import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
public class LibrarySystem {
    public static CompletableFuture<String> asyncUpdateBookInfo(String bookId, String newTitle, String newAuthor) {
        return CompletableFuture.supplyAsync(() -> {
            boolean updateResult = updateBookInfo(bookId, newTitle, newAuthor);
            if (updateResult) {
                return "Update successful";
            } else {
                return "Update failed";
            }
        });
    }
    private static boolean updateBookInfo(String bookId, String newTitle, String newAuthor) {
        return true;
    }
    public static void main(String[] args) throws ExecutionException, InterruptedException {
        CompletableFuture<String> updateFuture = asyncUpdateBookInfo("123", "新标题", "新作者");
        String result = updateFuture.get();
        System.out.println(result);
    }
}

Assume you are developing a system to manage library books and you need to implement a feature to update book information.

You need to implement a method named `asyncUpdateBookInfo` that takes three parameters: `bookId` (the book's ID, type `String`), `newTitle` (the new title of the book, type `String`), and `newAuthor` (the new author of the book, type `String`). The method should asynchronously update the book information and return `"Update successful"` when the update succeeds, or `"Update failed"` if it encounters any errors.

Please use `CompletableFuture` to implement the asynchronous operation and assume you already have a synchronous method `updateBookInfo(String bookId, String newTitle, String newAuthor)` that can be called, which returns `true` when the update is successful and `false` when it fails.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
public class LibrarySystem {
    public static CompletableFuture<String> asyncUpdateBookInfo(String bookId, String newTitle, String newAuthor) {
        return CompletableFuture.supplyAsync(() -> {
        });
    }
    private static boolean updateBookInfo(String bookId, String newTitle, String newAuthor) {
        return true;
    }
}
```

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;
public class LibrarySystemTest {
    @Test
    public void testAsyncUpdateBookInfoSuccessful() throws ExecutionException, InterruptedException {
        CompletableFuture<String> updateFuture = LibrarySystem.asyncUpdateBookInfo("123", "新标题", "新作者");
        String result = updateFuture.get();
        assertEquals("Update successful", result);
    }
    @Test
    public void testAsyncUpdateBookInfoDifferentBookId() throws ExecutionException, InterruptedException {
        CompletableFuture<String> updateFuture = LibrarySystem.asyncUpdateBookInfo("456", "Another Title", "Another Author");
        String result = updateFuture.get();
        assertEquals("Update successful", result);
    }
    @Test
    public void testAsyncUpdateBookInfoEmptyTitle() throws ExecutionException, InterruptedException {
        CompletableFuture<String> updateFuture = LibrarySystem.asyncUpdateBookInfo("123", "", "新作者");
        String result = updateFuture.get();
        assertEquals("Update successful", result);
    }
    @Test
    public void testAsyncUpdateBookInfoEmptyAuthor() throws ExecutionException, InterruptedException {
        CompletableFuture<String> updateFuture = LibrarySystem.asyncUpdateBookInfo("123", "新标题", "");
        String result = updateFuture.get();
        assertEquals("Update successful", result);
    }
    @Test
    public void testAsyncUpdateBookInfoEmptyFields() throws ExecutionException, InterruptedException {
        CompletableFuture<String> updateFuture = LibrarySystem.asyncUpdateBookInfo("123", "", "");
        String result = updateFuture.get();
        assertEquals("Update successful", result);
    }
}


import java.util.regex.Pattern;
public class EmailValidator {
    public static boolean isValidEmail(String email) {
        String emailRegex = "^[\\w-\\.]+@[\\w-]+\\.[\\w-]{2,}$";
        Pattern pattern = Pattern.compile(emailRegex);
        if (email == null) {
            return false;
        }
        return pattern.matcher(email).matches();
    }
    public static void main(String[] args) {
        System.out.println(isValidEmail("example@example.com"));
        System.out.println(isValidEmail("example@example"));
        System.out.println(isValidEmail("example@.com"));
        System.out.println(isValidEmail("example.com"));
        System.out.println(isValidEmail("@example.com"));
        System.out.println(isValidEmail(" example@example.com "));
        System.out.println(isValidEmail("example@example.com."));
        System.out.println(isValidEmail("exa mple@example.com"));
    }
}

Please write a Java method to verify whether a string meets the format requirements of an email address. The method should accept a string parameter and return `true` if the string is a valid email address, otherwise return `false`. A valid email address is defined as: it must contain an `@` symbol, there must be characters before and after the `@` symbol, and there must be at least one `.` symbol after the `@` symbol, with characters following the `.` symbol. Note that the email address should not contain spaces.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.regex.Pattern;
public class EmailValidator {
    public static boolean isValidEmail(String email) {
    }
}
```

Question: Write a piece of python code to achieve the following function.
Find the maximum perfect square number that is less than the nth Fibonacci number.
The function's name is max_square_number, and the input is an integer n.

Answer:
```python
def max_square_number(n):
 if n <= 2:
 return 0 # For the first two numbers in the Fibonacci sequence, no complete square numbers can be used.

 fibs = [0, 1] # Store the first two numbers of the Fibonacci sequence
 squares = [] # Store the list of perfect square numbers

 max_square = 0
 i = 2

 while i <= n:
 fibs.append(fibs[i-1] + fibs[i-2]) # Calculate the next Fibonacci number
 i += 1

 fib = fibs[-1]
 perfect_squares = [i**2 for i in range(1, int(math.sqrt(fib)) + 1)]
 max_square = max(filter(lambda x: x < fib, perfect_squares))
 return max_square
```

----------------

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
public class EmailValidatorTest {
    @Test
    public void testValidEmail() {
        Assertions.assertTrue(EmailValidator.isValidEmail("example@example.com"));
    }
    @Test
    public void testInvalidEmailWithoutDomain() {
        Assertions.assertFalse(EmailValidator.isValidEmail("example@example"));
    }
    @Test
    public void testInvalidEmailWithoutUsername() {
        Assertions.assertFalse(EmailValidator.isValidEmail("example@.com"));
    }
    @Test
    public void testInvalidEmailMissingAtSymbol() {
        Assertions.assertFalse(EmailValidator.isValidEmail("example.com"));
    }
    @Test
    public void testInvalidEmailWhitespace() {
        Assertions.assertFalse(EmailValidator.isValidEmail(" example@example.com "));
    }
    @Test
    public void testInvalidEmailSpecialCharacter() {
        Assertions.assertFalse(EmailValidator.isValidEmail("example@example.com."));
    }
    @Test
    public void testInvalidEmailSpaceInAddress() {
        Assertions.assertFalse(EmailValidator.isValidEmail("exa mple@example.com"));
    }
}


import java.text.ParseException;
import java.text.SimpleDateFormat;
public class DateTimeFormatter {
    public static String validateDateTime(String input) {
        SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        formatter.setLenient(false);
        try {
            formatter.parse(input);
            return "输入有效";
        } catch (ParseException e) {
            return "输入格式错误，请重新输入";
        }
    }
    public static void main(String[] args) {
        String[] testInputs = {
            "2023-04-01 12:00:00",
            "2023-02-29 12:00:00",
            "2023-04-01 25:00:00",
            "2023/04/01 12:00:00"
        };
        for (String input : testInputs) {
            System.out.println(validateDateTime(input));
        }
    }
}

Please modify the task to focus on specifying the requirements and conditions for validating user input of date and time in a Java program. The user will enter the date and time as a string in the format "yyyy-MM-dd HH:mm:ss". Ensure that the entered date and time are valid. If the input format is incorrect, specify that the program should return an error message indicating the issue. Utilize `SimpleDateFormat` and `ParseException` for validation. Describe that if the date and time are valid, the program should return "Input is valid", and if not, it should return "Input format error, please re-enter".
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.text.ParseException;
import java.text.SimpleDateFormat;
public class DateTimeFormatter {
    public static String validateDateTime(String input) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class DateTimeFormatterTest {
    @Test
    public void testValidDateTime() {
        String input = "2023-04-01 12:00:00";
        String result = DateTimeFormatter.validateDateTime(input);
        assertEquals("输入有效", result);
    }
    @Test
    public void testInvalidDateFormat() {
        String input = "2023/04/01 12:00:00";
        String result = DateTimeFormatter.validateDateTime(input);
        assertEquals("输入格式错误，请重新输入", result);
    }
    @Test
    public void testInvalidDateTimeHour() {
        String input = "2023-04-01 25:00:00";
        String result = DateTimeFormatter.validateDateTime(input);
        assertEquals("输入格式错误，请重新输入", result);
    }
    @Test
    public void testInvalidDateLeapYear() {
        String input = "2023-02-29 12:00:00";
        String result = DateTimeFormatter.validateDateTime(input);
        assertEquals("输入格式错误，请重新输入", result);
    }
    @Test
    public void testEdgeCaseValidDateTime() {
        String input = "2023-12-31 23:59:59";
        String result = DateTimeFormatter.validateDateTime(input);
        assertEquals("输入有效", result);
    }
}


import java.util.Arrays;
import java.util.List;
public class LandClassification {
    public static boolean isBuildingArea(int type) {
        List<Integer> buildingTypes = Arrays.asList(1, 2, 3, 4);
        return buildingTypes.contains(type);
    }
    public static void checkFunction() {
        assert isBuildingArea(1) : "住宅区应该被识别为建筑区域";
        assert isBuildingArea(2) : "商业区应该被识别为建筑区域";
        assert isBuildingArea(3) : "工业区应该被识别为建筑区域";
        assert isBuildingArea(4) : "公共设施区应该被识别为建筑区域";
        assert !isBuildingArea(5) : "绿地区域不应该被识别为建筑区域";
        assert !isBuildingArea(6) : "道路不应该被识别为建筑区域";
        assert !isBuildingArea(0) : "未分类区域不应该被识别为建筑区域";
        System.out.println("所有测试通过！");
    }
    public static void main(String[] args) {
        checkFunction();
    }
}

Please write a Java method to determine whether a plot of land belongs to a construction area. The type of the plot is represented by an integer `type`, where:

- `1` represents a residential area
- `2` represents a commercial area
- `3` represents an industrial area
- `4` represents a public facility area
- `5` represents a green area
- `6` represents a road
- Other numbers represent unclassified areas

If the plot belongs to a residential area, commercial area, industrial area, or public facility area, it is considered a construction area.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.Arrays;
import java.util.List;
public class LandClassification {
    public static boolean isBuildingArea(int type) {
    }
    public static void checkFunction() {
    }
}
```

import org.junit.Test;
import static org.junit.Assert.*;
public class LandClassificationTest {
    @Test
    public void testIsBuildingArea_ForResidentialArea() {
        assertTrue(LandClassification.isBuildingArea(1));
    }
    @Test
    public void testIsBuildingArea_ForCommercialArea() {
        assertTrue(LandClassification.isBuildingArea(2));
    }
    @Test
    public void testIsBuildingArea_ForIndustrialArea() {
        assertTrue(LandClassification.isBuildingArea(3));
    }
    @Test
    public void testIsBuildingArea_ForUnknownArea() {
        assertFalse(LandClassification.isBuildingArea(5));
    }
    @Test
    public void testIsBuildingArea_ForRoads() {
        assertFalse(LandClassification.isBuildingArea(6));
    }
}


import java.util.Optional;
public class TokenValidator {
    public Boolean validateAccessToken(String accessToken) {
        if (!isTokenFormatValid(accessToken)) {
            return false;
        }
        String storedToken = "abc123";
        return accessToken.equals(storedToken);
    }
    private boolean isTokenFormatValid(String token) {
        return token != null && token.length() > 5;
    }
    public static void main(String[] args) {
        TokenValidator validator = new TokenValidator();
        System.out.println("验证结果 (应为true): " + validator.validateAccessToken("abc123"));
        System.out.println("验证结果 (应为false): " + validator.validateAccessToken("abc"));
        System.out.println("验证结果 (应为false): " + validator.validateAccessToken(null));
    }
}

Please write a description of a Java method to validate a user's access token. The method should first check if the token format is correct, then compare it with the token stored in the database. If the token format is correct and matches the token in the database, it should return true; otherwise, it should return false. Ensure that your description considers handling possible exceptions and suggests using mock data in the database query to verify the method's correctness.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.Optional;
public class TokenValidator {
    public Boolean validateAccessToken(String accessToken) {
    }
    private boolean isTokenFormatValid(String token) {
    }
}
```

import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertTrue;
import org.junit.jupiter.api.Test;
public class TokenValidatorTest {
    @Test
    public void testValidateAccessToken_ValidToken() {
        TokenValidator validator = new TokenValidator();
        assertTrue(validator.validateAccessToken("abc123"));
    }
    @Test
    public void testValidateAccessToken_InvalidToken_ShortLength() {
        TokenValidator validator = new TokenValidator();
        assertFalse(validator.validateAccessToken("abc"));
    }
    @Test
    public void testValidateAccessToken_InvalidToken_Null() {
        TokenValidator validator = new TokenValidator();
        assertFalse(validator.validateAccessToken(null));
    }
    @Test
    public void testValidateAccessToken_InvalidToken_WrongToken() {
        TokenValidator validator = new TokenValidator();
        assertFalse(validator.validateAccessToken("wrongToken"));
    }
    @Test
    public void testValidateAccessToken_InvalidToken_EmptyString() {
        TokenValidator validator = new TokenValidator();
        assertFalse(validator.validateAccessToken(""));
    }
}


public class ParkingAssistant {
    public void autoStop(double distance) {
        if (distance <= 10.0) {
            System.out.println("停车成功");
        } else {
            System.out.println("继续行驶");
        }
    }
    public static void main(String[] args) {
        ParkingAssistant assistant = new ParkingAssistant();
        assistant.autoStop(5);
        assistant.autoStop(15);
        assistant.autoStop(10);
    }
}

Please write a Java program to implement a simple parking assistance system. When the vehicle approaches an obstacle at least 10 meters, the system should automatically stop the vehicle. You need to complete the following tasks:

- Define a class named `ParkingAssistant`.
- In this class, implement a method named `autoStop` that takes one parameter representing the distance between the vehicle and the obstacle (unit: meters).
- If the distance is less than or equal to 10 meters, the method should print "Parking successful", indicating the vehicle has stopped.
- Otherwise, print "Continue driving", indicating the vehicle can safely drive.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
public class ParkingAssistant {
    public void autoStop(double distance) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
public class ParkingAssistantTest {
    @Test
    public void testAutoStopWhenDistanceEqualToFive() {
        ParkingAssistant assistant = new ParkingAssistant();
        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
        System.setOut(new PrintStream(outContent));
        assistant.autoStop(5);
        assertTrue(outContent.toString().contains("停车成功"));
    }
    @Test
    public void testAutoStopWhenDistanceEqualToFifteen() {
        ParkingAssistant assistant = new ParkingAssistant();
        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
        System.setOut(new PrintStream(outContent));
        assistant.autoStop(15);
        assertTrue(outContent.toString().contains("继续行驶"));
    }
    @Test
    public void testAutoStopWhenDistanceEqualToTen() {
        ParkingAssistant assistant = new ParkingAssistant();
        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
        System.setOut(new PrintStream(outContent));
        assistant.autoStop(10);
        assertTrue(outContent.toString().contains("停车成功"));
    }
    @Test
    public void testAutoStopWhenDistanceLessThanTen() {
        ParkingAssistant assistant = new ParkingAssistant();
        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
        System.setOut(new PrintStream(outContent));
        assistant.autoStop(7.5);
        assertTrue(outContent.toString().contains("停车成功"));
    }
    @Test
    public void testAutoStopWhenDistanceGreaterThanTen() {
        ParkingAssistant assistant = new ParkingAssistant();
        ByteArrayOutputStream outContent = new ByteArrayOutputStream();
        System.setOut(new PrintStream(outContent));
        assistant.autoStop(12.5);
        assertTrue(outContent.toString().contains("继续行驶"));
    }
}


import java.util.Objects;
import java.util.Optional;
class Book {
    private String title;
    private Optional<String> audiobook;
    public Book(String title, Optional<String> audiobook) {
        this.title = title;
        this.audiobook = audiobook;
    }
    public Optional<String> getAudiobook() {
        return audiobook;
    }
}
class AudiobookChecker {
    public void checkAudiobook(Book book, Optional<String> expectedAudiobook) throws AudiobookMismatchException {
        if (!Objects.equals(book.getAudiobook(), expectedAudiobook)) {
            throw new AudiobookMismatchException("有声书版本不匹配");
        }
    }
}
class AudiobookMismatchException extends Exception {
    public AudiobookMismatchException(String message) {
        super(message);
    }
}
public class AudiobookCheckDemo {
    public static void main(String[] args) {
        Book book1 = new Book("Java Programming", Optional.of("Java Programming Audiobook"));
        Book book2 = new Book("Python Programming", Optional.empty());
        AudiobookChecker checker = new AudiobookChecker();
        try {
            checker.checkAudiobook(book1, Optional.of("Java Programming Audiobook"));
            System.out.println("书籍1有声书版本检查通过");
        } catch (AudiobookMismatchException e) {
            System.out.println(e.getMessage());
        }
        try {
            checker.checkAudiobook(book2, Optional.empty());
            System.out.println("书籍2有声书版本检查通过");
        } catch (AudiobookMismatchException e) {
            System.out.println(e.getMessage());
        }
        try {
            checker.checkAudiobook(book1, Optional.of("错误的有声书版本"));
        } catch (AudiobookMismatchException e) {
            System.out.println("书籍1有声书版本检查未通过: " + e.getMessage());
        }
    }
}

Assume you are developing a book management system and need to implement a feature to check whether a book has an audiobook version.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.Objects;
import java.util.Optional;
class Book {
    private String title;
    private Optional<String> audiobook;
    public Book(String title, Optional<String> audiobook) {}
    public Optional<String> getAudiobook() {}
}
class AudiobookChecker {
    public void checkAudiobook(Book book, Optional<String> expectedAudiobook) throws AudiobookMismatchException {}
}
class AudiobookMismatchException extends Exception {
    public AudiobookMismatchException(String message) {}
}
```

import java.util.Optional;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
class BookTest {
    @Test
    void testGetAudiobook() {
        Book bookWithAudiobook = new Book("Java Programming", Optional.of("Java Programming Audiobook"));
        assertEquals(Optional.of("Java Programming Audiobook"), bookWithAudiobook.getAudiobook());
        Book bookWithoutAudiobook = new Book("Python Programming", Optional.empty());
        assertEquals(Optional.empty(), bookWithoutAudiobook.getAudiobook());
    }
}
class AudiobookCheckerTest {
    @Test
    void testCheckAudiobookMatch() throws AudiobookMismatchException {
        Book book = new Book("Java Programming", Optional.of("Java Programming Audiobook"));
        AudiobookChecker checker = new AudiobookChecker();
        checker.checkAudiobook(book, Optional.of("Java Programming Audiobook"));
    }
    @Test
    void testCheckAudiobookMismatch() {
        Book book = new Book("Java Programming", Optional.of("Java Programming Audiobook"));
        AudiobookChecker checker = new AudiobookChecker();
        assertThrows(AudiobookMismatchException.class, () -> {
            checker.checkAudiobook(book, Optional.of("Wrong Audiobook"));
        });
    }
    @Test
    void testCheckAudiobookEmptyMatch() throws AudiobookMismatchException {
        Book book = new Book("Python Programming", Optional.empty());
        AudiobookChecker checker = new AudiobookChecker();
        checker.checkAudiobook(book, Optional.empty());
    }
    @Test
    void testCheckAudiobookEmptyMismatch() {
        Book book = new Book("Python Programming", Optional.empty());
        AudiobookChecker checker = new AudiobookChecker();
        assertThrows(AudiobookMismatchException.class, () -> {
            checker.checkAudiobook(book, Optional.of("Some Audiobook"));
        });
    }
}


import java.util.Objects;
class StudentScore {
    private int studentId;
    private String studentName;
    private int mathScore;
    private int englishScore;
    private int scienceScore;
    public StudentScore(int studentId, String studentName, int mathScore, int englishScore, int scienceScore) {
        this.studentId = studentId;
        this.studentName = studentName;
        this.mathScore = mathScore;
        this.englishScore = englishScore;
        this.scienceScore = scienceScore;
    }
    @Override
    public String toString() {
        return "StudentScore{" +
                "studentId=" + studentId +
                ", studentName='" + studentName + '\'' +
                ", mathScore=" + mathScore +
                ", englishScore=" + englishScore +
                ", scienceScore=" + scienceScore +
                '}';
    }
}
public class ScoreProcessor {
    public StudentScore generateStudentScore(Object[] objectArray) {
        int studentId = Integer.parseInt(String.valueOf(objectArray[0]));
        String studentName = String.valueOf(objectArray[1]);
        int mathScore = Integer.parseInt(String.valueOf(objectArray[2]));
        int englishScore = Integer.parseInt(String.valueOf(objectArray[3]));
        int scienceScore = Integer.parseInt(String.valueOf(objectArray[4]));
        return new StudentScore(studentId, studentName, mathScore, englishScore, scienceScore);
    }
    public static void main(String[] args) {
        ScoreProcessor processor = new ScoreProcessor();
        Object[] data = {1, "张三", "90", "85", "88"};
        StudentScore score = processor.generateStudentScore(data);
        System.out.println(score);
    }
}

Please write a Java program to handle student grade information. Given an array of objects, each object represents different grade information of a student, including student ID, name, math grade, English grade, science grade, etc. You need to encapsulate this information into a student grade object and return this object. Please ensure that your code can handle different data types; for example, the math grade may be given in string form and needs to be converted to an integer.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.Objects;
class StudentScore {
    private int studentId;
    private String studentName;
    private int mathScore;
    private int englishScore;
    private int scienceScore;
    public StudentScore(int studentId, String studentName, int mathScore, int englishScore, int scienceScore) {
    }
    @Override
    public String toString() {
    }
}
public class ScoreProcessor {
    public StudentScore generateStudentScore(Object[] objectArray) {
    }
}
```

import org.junit.Test;
import static org.junit.Assert.*;
public class ScoreProcessorTest {
    @Test(expected = ArrayIndexOutOfBoundsException.class)
    public void testGenerateStudentScoreWithEmptyArray() {
        ScoreProcessor processor = new ScoreProcessor();
        Object[] emptyArray = {};
        processor.generateStudentScore(emptyArray);
    }
    @Test(expected = NumberFormatException.class)
    public void testGenerateStudentScoreWithInvalidDataType() {
        ScoreProcessor processor = new ScoreProcessor();
        Object[] invalidDataArray = {1, "张三", "NotANumber", "85", "88"};
        processor.generateStudentScore(invalidDataArray);
    }
    @Test
    public void testGenerateStudentScoreWithValidData(){
        ScoreProcessor processor = new ScoreProcessor();
        Object[] data = {1, "张三", "90", "85", "88"};
        StudentScore expected = new StudentScore(1, "张三", 90, 85, 88);
        StudentScore actual = processor.generateStudentScore(data);
        assertEquals(expected.toString(), actual.toString());
    }
    @Test
    public void testGenerateStudentScoreWithNegativeScores() {
        ScoreProcessor processor = new ScoreProcessor();
        Object[] data = {2, "李四", "-10", "85", "88"};
        StudentScore expected = new StudentScore(2, "李四", -10, 85, 88);
        StudentScore actual = processor.generateStudentScore(data);
        assertEquals(expected.toString(), actual.toString());
    }
    @Test
    public void testGenerateStudentScoreWithEmptyName() {
        ScoreProcessor processor = new ScoreProcessor();
        Object[] data = {3, "", "50", "75", "90"};
        StudentScore expected = new StudentScore(3, "", 50, 75, 90);
        StudentScore actual = processor.generateStudentScore(data);
        assertEquals(expected.toString(), actual.toString());
    }
}


import java.util.Scanner;
public class SimpleCalculator {
    public double add(double a, double b) {
        return a + b;
    }
    public double subtract(double a, double b) {
        return a - b;
    }
    public double multiply(double a, double b) {
        return a * b;
    }
    public double divide(double a, double b) {
        if (b == 0) {
            System.out.println("错误：除数不能为0。");
            return 0;
        }
        return a / b;
    }
    public static void main(String[] args) {
        SimpleCalculator calculator = new SimpleCalculator();
        Scanner scanner = new Scanner(System.in);
        System.out.println("请输入两个数字和一个操作符（+、-、*、/），例如：3 + 4");
        double num1 = scanner.nextDouble();
        String operator = scanner.next();
        double num2 = scanner.nextDouble();
        switch (operator) {
            case "+":
                System.out.println("结果是：" + calculator.add(num1, num2));
                break;
            case "-":
                System.out.println("结果是：" + calculator.subtract(num1, num2));
                break;
            case "*":
                System.out.println("结果是：" + calculator.multiply(num1, num2));
                break;
            case "/":
                System.out.println("结果是：" + calculator.divide(num1, num2));
                break;
            default:
                System.out.println("未知的操作符：" + operator);
                break;
        }
    }
}

Please write a Java program to implement a simple calculator class `SimpleCalculator`. This class should be able to perform basic arithmetic operations: addition, subtraction, multiplication, and division. Ensure that your implementation can handle division by zero and, in such cases, print a friendly error message instead of crashing the program. Ensure that your code is easy to understand, with reasonable variable naming, and includes necessary comments.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.Scanner;
public class SimpleCalculator {
    public double add(double a, double b) {
    }
    public double subtract(double a, double b) {
    }
    public double multiply(double a, double b) {
    }
    public double divide(double a, double b) {
    }
}
```

import static org.junit.jupiter.api.Assertions.assertEquals;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
public class SimpleCalculatorTest {
    private SimpleCalculator calculator;
    @BeforeEach
    public void setUp() {
        calculator = new SimpleCalculator();
    }
    @Test
    public void testAdd() {
        double result = calculator.add(2, 3);
        assertEquals(5, result, 0.001);
    }
    @Test
    public void testSubtract() {
        double result = calculator.subtract(5, 3);
        assertEquals(2, result, 0.001);
    }
    @Test
    public void testMultiply() {
        double result = calculator.multiply(4, 3);
        assertEquals(12, result, 0.001);
    }
    @Test
    public void testDivide() {
        double result = calculator.divide(6, 3);
        assertEquals(2, result, 0.001);
    }
    @Test
    public void testDivideByZero() {
        double result = calculator.divide(6, 0);
        assertEquals(0, result, 0.001);
    }
}


import java.util.HashMap;
import java.util.Map;
public class HealthAdvice {
    public static String getHealthAdvice(int age) {
        if (age < 12) {
            return "多喝水";
        } else if (age >= 12 && age <= 18) {
            return "保持适当的运动";
        } else if (age >= 19 && age <= 40) {
            return "保持健康饮食";
        } else if (age >= 41 && age <= 60) {
            return "定期体检";
        } else {
            return "保持积极的生活态度";
        }
    }
    public static void checkHealthAdvice() {
        Map<Integer, String> testCases = new HashMap<>();
        testCases.put(5, "多喝水");
        testCases.put(15, "保持适当的运动");
        testCases.put(30, "保持健康饮食");
        testCases.put(50, "定期体检");
        testCases.put(70, "保持积极的生活态度");
        boolean isCorrect = true;
        for (Map.Entry<Integer, String> entry : testCases.entrySet()) {
            String advice = getHealthAdvice(entry.getKey());
            if (!advice.equals(entry.getValue())) {
                isCorrect = false;
                System.out.println("错误: 对于年龄 " + entry.getKey() + " 的建议应该是 '" + entry.getValue() + "'，但你的方法返回了 '" + advice + "'");
            }
        }
        if (isCorrect) {
            System.out.println("所有测试用例都通过了！");
        }
    }
    public static void main(String[] args) {
        checkHealthAdvice();
    }
}

Please write a Java method that returns corresponding health advice based on the user's age. Specific requirements are as follows:

- If the user's age is less than 12 years old, the advice is "Drink plenty of water".
- If the user's age is between 12 and 18 years old (including 12 and 18), the advice is "Maintain proper exercise".
- If the user's age is between 19 and 40 years old (including 19 and 40), the advice is "Maintain a healthy diet".
- If the user's age is between 41 and 60 years old (including 41 and 60), the advice is "Have regular checkups".
- If the user's age is over 60 years old, the advice is "Stay positive".
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.HashMap;
import java.util.Map;
public class HealthAdvice {
    public static String getHealthAdvice(int age) {
    }
    public static void checkHealthAdvice() {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class HealthAdviceTest {
    @Test
    public void testGetHealthAdviceUnder12() {
        assertEquals("多喝水", HealthAdvice.getHealthAdvice(5));
    }
    @Test
    public void testGetHealthAdviceBetween12And18() {
        assertEquals("保持适当的运动", HealthAdvice.getHealthAdvice(15));
    }
    @Test
    public void testGetHealthAdviceBetween19And40() {
        assertEquals("保持健康饮食", HealthAdvice.getHealthAdvice(30));
    }
    @Test
    public void testGetHealthAdviceBetween41And60() {
        assertEquals("定期体检", HealthAdvice.getHealthAdvice(50));
    }
    @Test
    public void testGetHealthAdviceAbove60() {
        assertEquals("保持积极的生活态度", HealthAdvice.getHealthAdvice(70));
    }
}


import java.util.ArrayList;
import java.util.List;
public class DataProcessor {
    public List<String> processData(List<String> lines) {
        List<String> result = new ArrayList<>();
        for (String line : lines) {
            if (!line.startsWith("#")) {
                result.add(line.toUpperCase());
            }
        }
        return result;
    }
    public boolean checkResult(List<String> input, List<String> expected) {
        List<String> output = processData(input);
        return output.equals(expected);
    }
    public static void main(String[] args) {
        DataProcessor processor = new DataProcessor();
        List<String> input = List.of("# This is a comment", "Hello, World!", "Java Programming");
        List<String> expected = List.of("HELLO, WORLD!", "JAVA PROGRAMMING");
        boolean isCorrect = processor.checkResult(input, expected);
        System.out.println("The processData method is " + (isCorrect ? "correct" : "incorrect"));
    }
}

Please design a Java program to handle data from a text file and convert it into a specific format output. Specifically, you need to write a class named `DataProcessor` that contains a method named `processData`. This method takes a list of strings as input, with each string representing a line of data from the file. You need to convert each line of data based on the following rules: if a line starts with "#", ignore that line; otherwise, convert the line to uppercase and add it to the result list. Finally, the `processData` method returns the list of converted data.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.ArrayList;
import java.util.List;
public class DataProcessor {
    public List<String> processData(List<String> lines) {
    }
    public boolean checkResult(List<String> input, List<String> expected) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
import java.util.ArrayList;
import java.util.List;
public class DataProcessorTest {
    @Test
    public void testProcessData_withComments() {
        DataProcessor processor = new DataProcessor();
        List<String> input = List.of("# This is a comment", "Hello, World!", "Java Programming");
        List<String> expected = List.of("HELLO, WORLD!", "JAVA PROGRAMMING");
        List<String> result = processor.processData(input);
        assertEquals(expected, result);
    }
    @Test
    public void testProcessData_withoutComments() {
        DataProcessor processor = new DataProcessor();
        List<String> input = List.of("Hello, World!", "Java Programming");
        List<String> expected = List.of("HELLO, WORLD!", "JAVA PROGRAMMING");
        List<String> result = processor.processData(input);
        assertEquals(expected, result);
    }
    @Test
    public void testProcessData_emptyList() {
        DataProcessor processor = new DataProcessor();
        List<String> input = new ArrayList<>();
        List<String> expected = new ArrayList<>();
        List<String> result = processor.processData(input);
        assertEquals(expected, result);
    }
    @Test
    public void testCheckResult_correct() {
        DataProcessor processor = new DataProcessor();
        List<String> input = List.of("Goodbye, World!", "Unit Testing");
        List<String> expected = List.of("GOODBYE, WORLD!", "UNIT TESTING");
        boolean result = processor.checkResult(input, expected);
        assertTrue(result);
    }
    @Test
    public void testCheckResult_incorrect() {
        DataProcessor processor = new DataProcessor();
        List<String> input = List.of("Goodbye, World!", "Unit Testing");
        List<String> expected = List.of("GOODBYE, WORLD!");
        boolean result = processor.checkResult(input, expected);
        assertFalse(result);
    }
}


import java.util.Objects;
public class Student {
    private String name;
    private int id;
    public Student(String name, int id) {
        this.name = name;
        this.id = id;
    }
    @Override
    public boolean equals(Object obj) {
        if (this == obj) return true;
        if (!(obj instanceof Student)) return false;
        Student other = (Student) obj;
        return Objects.equals(name, other.name) && id == other.id;
    }
    public static void main(String[] args) {
        Student student1 = new Student("张三", 101);
        Student student2 = new Student("张三", 101);
        Student student3 = new Student("李四", 102);
        System.out.println("student1 和 student2 是否相等: " + student1.equals(student2));
        System.out.println("student1 和 student3 是否相等: " + student1.equals(student3));
    }
}

Please design a Java program to compare whether two student objects are equal. The student object includes a name (String type) and a student ID (int type). If both the names and student IDs of the two students are the same, then the two student objects are considered equal. Please implement a method `equals` to complete this comparison.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.Objects;
public class Student {
    private String name;
    private int id;
    public Student(String name, int id) {
    }
    @Override
    public boolean equals(Object obj) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class StudentTest {
    @Test
    public void testEqualsSameObject() {
        Student student = new Student("张三", 101);
        assertTrue(student.equals(student));
    }
    @Test
    public void testEqualsDifferentType() {
        Student student = new Student("张三", 101);
        Object obj = new Object();
        assertFalse(student.equals(obj));
    }
    @Test
    public void testEqualsEqualObjects() {
        Student student1 = new Student("张三", 101);
        Student student2 = new Student("张三", 101);
        assertTrue(student1.equals(student2));
    }
    @Test
    public void testEqualsDifferentObjects() {
        Student student1 = new Student("张三", 101);
        Student student3 = new Student("李四", 102);
        assertFalse(student1.equals(student3));
    }
    @Test
    public void testEqualsNullObject() {
        Student student1 = new Student("张三", 101);
        assertFalse(student1.equals(null));
    }
}


import java.util.HashMap;
import java.util.Map;
public class BookManager {
    private Map<String, String> books;
    public BookManager() {
        books = new HashMap<>();
        books.put("978-3-16-148410-0", "《Java编程思想》");
        books.put("978-4-16-148410-1", "《Effective Java》");
        books.put("978-5-16-148410-2", "《Java并发编程实战》");
    }
    public String searchBookByISBN(String isbn) {
        return books.getOrDefault(isbn, "未找到图书");
    }
    public static void main(String[] args) {
        BookManager manager = new BookManager();
        System.out.println(manager.searchBookByISBN("978-3-16-148410-0"));
        System.out.println(manager.searchBookByISBN("000-0-00-000000-0"));
    }
}

Please write a Java program to manage the book information in a library. Implement a feature that allows users to search for book details by ISBN number and display the results on the console. Ensure your program can handle situations where no book is found, in which case it should output "Book not found."
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.HashMap;
import java.util.Map;
public class BookManager {
    private Map<String, String> books;
    public BookManager() {
    }
    public String searchBookByISBN(String isbn) {
    }
}
```

import static org.junit.Assert.*;
import org.junit.Before;
import org.junit.Test;
public class BookManagerTest {
    private BookManager bookManager;
    @Before
    public void setUp() throws Exception {
        bookManager = new BookManager();
    }
    @Test
    public void testSearchBookByExistingISBN() {
        String result = bookManager.searchBookByISBN("978-3-16-148410-0");
        assertEquals("《Java编程思想》", result);
    }
    @Test
    public void testSearchBookByNonExistingISBN() {
        String result = bookManager.searchBookByISBN("000-0-00-000000-0");
        assertEquals("未找到图书", result);
    }
    @Test
    public void testSearchBookByAnotherExistingISBN() {
        String result = bookManager.searchBookByISBN("978-4-16-148410-1");
        assertEquals("《Effective Java》", result);
    }
    @Test
    public void testSearchBookByAnotherExistingISBN2() {
        String result = bookManager.searchBookByISBN("978-5-16-148410-2");
        assertEquals("《Java并发编程实战》", result);
    }
    @Test
    public void testSearchBookWithNullISBN() {
        String result = bookManager.searchBookByISBN(null);
        assertEquals("未找到图书", result);
    }
}


import java.util.Objects;
public class Book {
    private String author;
    public Book(String author) {
        this.author = author;
    }
    public String getAuthorName() {
        return author;
    }
    public static void main(String[] args) {
        check("路遥", new Book("路遥").getAuthorName());
        check("鲁迅", new Book("鲁迅").getAuthorName());
    }
    public static void check(String expected, String actual) {
        if (Objects.equals(expected, actual)) {
            System.out.println("测试通过");
        } else {
            System.out.println("测试失败");
        }
    }
}

Please write a Java program to implement a function of a simple book management system: getting the current book's author name. In this system, each book has an author. Please define a `Book` class that contains a private member variable `author` (a string representing the author's name), and provide a public method `getAuthorName` to return the name of the book's author.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.Objects;
public class Book {
    private String author;
    public Book(String author) {
    }
    public String getAuthorName() {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;
public class BookTest {
    @Test
    public void testAuthorNameIsLuYao() {
        Book book = new Book("路遥");
        assertEquals("路遥", book.getAuthorName());
    }
    @Test
    public void testAuthorNameIsLuXun() {
        Book book = new Book("鲁迅");
        assertEquals("鲁迅", book.getAuthorName());
    }
    @Test
    public void testAuthorNameIsNull() {
        Book book = new Book(null);
        assertEquals(null, book.getAuthorName());
    }
    @Test
    public void testAuthorNameIsEmpty() {
        Book book = new Book("");
        assertEquals("", book.getAuthorName());
    }
    @Test
    public void testAuthorNameIsDifferent() {
        Book book = new Book("韩寒");
        assertEquals("韩寒", book.getAuthorName());
    }
}


import java.io.*;
class Employee implements Serializable {
    private String name;
    private int id;
    public Employee(String name, int id) {
        this.name = name;
        this.id = id;
    }
    @Override
    public String toString() {
        return "Employee{" +
                "name='" + name + '\'' +
                ", id=" + id +
                '}';
    }
}
public class EmployeeSerializationDemo {
    public static void serializeEmployee(Employee emp, String filePath) {
        try (ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(filePath))) {
            out.writeObject(emp);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static Employee deserializeEmployee(String filePath) {
        Employee emp = null;
        try (ObjectInputStream in = new ObjectInputStream(new FileInputStream(filePath))) {
            emp = (Employee) in.readObject();
        } catch (IOException | ClassNotFoundException e) {
            e.printStackTrace();
        }
        return emp;
    }
    public static void main(String[] args) {
        String filePath = "employee.ser";
        Employee emp = new Employee("张三", 12345);
        serializeEmployee(emp, filePath);
        System.out.println("Employee对象序列化成功");
        Employee deserializedEmp = deserializeEmployee(filePath);
        System.out.println("反序列化的Employee对象: " + deserializedEmp);
    }
}

Please write a Java program to serialize an `Employee` object to a file, and then deserialize the object from the file. Ensure that your program can handle potential exceptions and properly close all resources after the operation. You need to define an `Employee` class, which should contain at least two properties: `name` and `id`, and this class must implement the `Serializable` interface. Provide a `serializeEmployee` method for object serialization and a `deserializeEmployee` method for object deserialization.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.io.*;
class Employee implements Serializable {
    private String name;
    private int id;
    public Employee(String name, int id) {
    }
    @Override
    public String toString() {
    }
}
public class EmployeeSerializationDemo {
    public static void serializeEmployee(Employee emp, String filePath) {
    }
    public static Employee deserializeEmployee(String filePath) {
    }
}
```

import static org.junit.Assert.*;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.io.*;
class EmployeeTest {
    private final String filePath = "employee_test.ser";
    private Employee emp;
    @Before
    public void setUp() {
        emp = new Employee("张三", 12345);
    }
    @After
    public void tearDown() {
        new File(filePath).delete();
    }
    @Test
    public void testSerializeEmployeeNotNull() {
        EmployeeSerializationDemo.serializeEmployee(emp, filePath);
        assertNotNull(new File(filePath).exists());
    }
    @Test
    public void testDeserializeEmployee() {
        EmployeeSerializationDemo.serializeEmployee(emp, filePath);
        Employee deserializedEmp = EmployeeSerializationDemo.deserializeEmployee(filePath);
        assertEquals(emp.toString(), deserializedEmp.toString());
    }
    @Test
    public void testDeserializeEmployeeFileNotFound() {
        Employee deserializedEmp = EmployeeSerializationDemo.deserializeEmployee("non_existent_file.ser");
        assertNull(deserializedEmp);
    }
    @Test
    public void testSerializeEmployeeIOException() {
        String invalidPath = "";
        EmployeeSerializationDemo.serializeEmployee(emp, invalidPath);
        assertFalse(new File(invalidPath).exists());
    }
    @Test
    public void testDeserializeEmployeeClassNotFound() {
        try (ObjectOutputStream out = new ObjectOutputStream(new FileOutputStream(filePath))) {
            out.writeObject("String object");
        } catch (IOException e) {
            e.printStackTrace();
        }
        Employee deserializedEmp = EmployeeSerializationDemo.deserializeEmployee(filePath);
        assertNull(deserializedEmp);
    }
}


import java.awt.Color;
import java.awt.image.BufferedImage;
public class ColorInverter {
    public static BufferedImage invertColors(BufferedImage originalImage) {
        int width = originalImage.getWidth();
        int height = originalImage.getHeight();
        BufferedImage invertedImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        for (int y = 0; y < height; y++) {
            for (int x = 0; x < width; x++) {
                Color originalColor = new Color(originalImage.getRGB(x, y));
                int red = 255 - originalColor.getRed();
                int green = 255 - originalColor.getGreen();
                int blue = 255 - originalColor.getBlue();
                Color invertedColor = new Color(red, green, blue);
                invertedImage.setRGB(x, y, invertedColor.getRGB());
            }
        }
        return invertedImage;
    }
    public static void checkFunction() {
        System.out.println("检查逻辑需要根据实际情况实现");
    }
    public static void main(String[] args) {
        BufferedImage originalImage = null;
        BufferedImage resultImage = invertColors(originalImage);
    }
}

Please modify the Java program to invert the colors of an image. Given an image (assumed to be an instance of the `MyPicture` class), invert the RGB values of each pixel in the image. The new RGB value should be calculated as `255 - original RGB value`. Ensure that the processed image has RGB values within the range of 0 to 255. Implement a method named `invertColors` that takes a `MyPicture` object as input and returns a new `MyPicture` object representing the processed image.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.awt.Color;
import java.awt.image.BufferedImage;
public class ColorInverter {
    public static BufferedImage invertColors(BufferedImage originalImage) {
    }
    public static void checkFunction() {
    }
}
```

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import java.awt.Color;
import java.awt.image.BufferedImage;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
public class ColorInverterTest {
    private BufferedImage originalImage;
    @BeforeEach
    public void setUp() {
        originalImage = new BufferedImage(2, 2, BufferedImage.TYPE_INT_RGB);
        originalImage.setRGB(0, 0, new Color(100, 150, 200).getRGB());
        originalImage.setRGB(0, 1, new Color(50, 50, 50).getRGB());
        originalImage.setRGB(1, 0, new Color(0, 0, 0).getRGB());
        originalImage.setRGB(1, 1, new Color(255, 255, 255).getRGB());
    }
    @Test
    public void testInvertColors_NotNull() {
        BufferedImage invertedImage = ColorInverter.invertColors(originalImage);
        assertNotNull(invertedImage);
    }
    @Test
    public void testInvertColors_Dimensions() {
        BufferedImage invertedImage = ColorInverter.invertColors(originalImage);
        assertEquals(originalImage.getWidth(), invertedImage.getWidth());
        assertEquals(originalImage.getHeight(), invertedImage.getHeight());
    }
    @Test
    public void testInvertColors_CorrectInversion() {
        BufferedImage invertedImage = ColorInverter.invertColors(originalImage);
        Color originalColor0_0 = new Color(originalImage.getRGB(0, 0));
        Color invertedColor0_0 = new Color(invertedImage.getRGB(0, 0));
        assertEquals(255 - originalColor0_0.getRed(), invertedColor0_0.getRed());
        assertEquals(255 - originalColor0_0.getGreen(), invertedColor0_0.getGreen());
        assertEquals(255 - originalColor0_0.getBlue(), invertedColor0_0.getBlue());
        Color originalColor1_1 = new Color(originalImage.getRGB(1, 1));
        Color invertedColor1_1 = new Color(invertedImage.getRGB(1, 1));
        assertEquals(255 - originalColor1_1.getRed(), invertedColor1_1.getRed());
        assertEquals(255 - originalColor1_1.getGreen(), invertedColor1_1.getGreen());
        assertEquals(255 - originalColor1_1.getBlue(), invertedColor1_1.getBlue());
    }
    @Test
    public void testInvertColors_BlackToWhite() {
        originalImage.setRGB(0, 0, Color.BLACK.getRGB());
        BufferedImage invertedImage = ColorInverter.invertColors(originalImage);
        assertEquals(Color.WHITE.getRGB(), invertedImage.getRGB(0, 0));
    }
    @Test
    public void testInvertColors_WhiteToBlack() {
        originalImage.setRGB(0, 0, Color.WHITE.getRGB());
        BufferedImage invertedImage = ColorInverter.invertColors(originalImage);
        assertEquals(Color.BLACK.getRGB(), invertedImage.getRGB(0, 0));
    }
}


import java.util.OptionalDouble;
public double retrieveGlobalStatistic(String statisticName, double fallbackValue) {
    OptionalDouble result = GlobalStatsDatabase.queryStatistic(statisticName);
    return result.orElse(fallbackValue);
}
class GlobalStatsDatabase {
    public static OptionalDouble queryStatistic(String name) {
        if ("playerCount".equals(name)) {
            return OptionalDouble.of(1000000.0);
        } else if ("averageScore".equals(name)) {
            return OptionalDouble.of(350.5);
        }
        return OptionalDouble.empty();
    }
}
public static void main(String[] args) {
    double playerCount = retrieveGlobalStatistic("playerCount", 0.0);
    double averageScore = retrieveGlobalStatistic("averageScore", 0.0);
    double nonExistingStat = retrieveGlobalStatistic("nonExistingStat", 10.0);
    System.out.println("Player Count: " + playerCount);
    System.out.println("Average Score: " + averageScore);
    System.out.println("Non-existing Stat: " + nonExistingStat);
}

Please write a Java method that retrieves the value of a specified statistic from a simulated global statistics database. If the statistic exists, return its value; if it does not, return a default value. Please implement the method according to the following requirements:

- The method name should be `retrieveGlobalStatistic`.
- It accepts two parameters: a `String` named `statisticName` which represents the name of the statistic, and a `double` named `fallbackValue` which represents the default value.
- Assume there is an external library providing a class named `GlobalStatsDatabase`, which has a static method `queryStatistic` that accepts a `String` parameter and returns an `OptionalDouble` result.
- If the `OptionalDouble` returned by `queryStatistic` has a value, return that value; otherwise, return `fallbackValue`.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.OptionalDouble;
public double retrieveGlobalStatistic(String statisticName, double fallbackValue) {
}
class GlobalStatsDatabase {
    public static OptionalDouble queryStatistic(String name) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
import java.util.OptionalDouble;
class GlobalStatsDatabaseTest {
    public double retrieveGlobalStatistic(String statisticName, double fallbackValue) {
        OptionalDouble result = GlobalStatsDatabase.queryStatistic(statisticName);
        return result.orElse(fallbackValue);
    }
    static class GlobalStatsDatabase {
        public static OptionalDouble queryStatistic(String name) {
            if ("playerCount".equals(name)) {
                return OptionalDouble.of(1000000.0);
            } else if ("averageScore".equals(name)) {
                return OptionalDouble.of(350.5);
            }
            return OptionalDouble.empty();
        }
    }
    @Test
    void testPlayerCount() {
        double result = retrieveGlobalStatistic("playerCount", 0.0);
        assertEquals(1000000.0, result);
    }
    @Test
    void testAverageScore() {
        double result = retrieveGlobalStatistic("averageScore", 0.0);
        assertEquals(350.5, result);
    }
    @Test
    void testNonExistingStat() {
        double result = retrieveGlobalStatistic("nonExistingStat", 10.0);
        assertEquals(10.0, result);
    }
    @Test
    void testFallbackValueForNonExistingStat() {
        double result = retrieveGlobalStatistic("someRandomStat", 5.5);
        assertEquals(5.5, result);
    }
    @Test
    void testFallbackValueForEmptyStringStat() {
        double result = retrieveGlobalStatistic("", 1.1);
        assertEquals(1.1, result);
    }
}


import java.util.HashMap;
class Book {
    String title;
    String author;
    String isbn;
    public Book(String title, String author, String isbn) {
        this.title = title;
        this.author = author;
        this.isbn = isbn;
    }
}
public class BookManager {
    static HashMap<String, Book> libraryBooks = new HashMap<>();
    static {
        libraryBooks.put("123456789", new Book("Java Programming", "John Doe", "123456789"));
        libraryBooks.put("987654321", new Book("Python Programming", "Jane Doe", "987654321"));
    }
    public static boolean isBookAvailable(String isbn) {
        return libraryBooks.containsKey(isbn);
    }
    public static void checkAvailability(String[] isbns) {
        for (String isbn : isbns) {
            System.out.println("ISBN " + isbn + ": " + (isBookAvailable(isbn) ? "Available" : "Not Available"));
        }
    }
    public static void main(String[] args) {
        String[] testIsbns = {"123456789", "987654321", "111111111"};
        checkAvailability(testIsbns);
    }
}

Please write a Java program to manage the book information in a library. The specific requirements are as follows:

- A `Book` class is required, containing the book title (`title`), author (`author`), and ISBN number (`isbn`).
- In the `BookManager` class, implement a method `isBookAvailable` that accepts an ISBN number as a parameter and returns a boolean value indicating whether the book is available in the library.
- To simplify the problem, assume that the book information of the library is stored in a static `HashMap`, with the key being the ISBN number and the value being the `Book` object.
- Provide a `checkAvailability` method to verify the correctness of the `isBookAvailable` method. This method should be able to check several ISBN numbers and print whether each ISBN number corresponds to an available book.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.HashMap;
class Book {
    String title;
    String author;
    String isbn;
    public Book(String title, String author, String isbn) {
    }
}
public class BookManager {
    static HashMap<String, Book> libraryBooks = new HashMap<>();
    static {
    }
    public static boolean isBookAvailable(String isbn) {
    }
    public static void checkAvailability(String[] isbns) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class BookManagerTest {
    @Test
    public void testIsBookAvailableAvailable() {
        assertTrue(BookManager.isBookAvailable("123456789"));
    }
    @Test
    public void testIsBookAvailableNotAvailable() {
        assertFalse(BookManager.isBookAvailable("111111111"));
    }
    @Test
    public void testIsBookAvailableAnotherBook() {
        assertTrue(BookManager.isBookAvailable("987654321"));
    }
    @Test
    public void testCheckAvailabilityWithOnlyAvailableBooks() {
        String[] isbns = {"123456789", "987654321"};
        BookManager.checkAvailability(isbns);
    }
    @Test
    public void testCheckAvailabilityWithMixedBooks() {
        String[] isbns = {"123456789", "987654321", "111111111"};
        BookManager.checkAvailability(isbns);
    }
}


import java.util.HashMap;
import java.util.Map;
public class ShoppingCart {
    private Map<String, Integer> cart;
    public ShoppingCart() {
        cart = new HashMap<>();
    }
    public void addProduct(String productId, int quantity) {
        cart.merge(productId, quantity, Integer::sum);
    }
    public void removeProduct(String productId) throws Exception {
        if (!cart.containsKey(productId)) {
            throw new Exception("Product not found in the cart.");
        }
        cart.remove(productId);
    }
    public boolean checkProductExists(String productId) {
        return cart.containsKey(productId);
    }
    public static void main(String[] args) {
        ShoppingCart cart = new ShoppingCart();
        try {
            cart.addProduct("apple", 2);
            cart.addProduct("banana", 3);
            cart.addProduct("apple", 1);
            System.out.println(cart.checkProductExists("apple"));
            cart.removeProduct("banana");
            System.out.println(cart.checkProductExists("banana"));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Please design the functionality for a simple shopping cart in Java. In this shopping cart, users should be able to add items to the cart, as well as remove items from the cart. Each item has a unique identifier. If the user attempts to add an item that already exists in the cart, the program should update the quantity of that item instead of adding it again. Similarly, if the user attempts to remove an item that does not exist in the cart, the program should alert the user. Design the logic to handle these scenarios, and ensure there is a way to check if a specific item exists in the cart.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.HashMap;
import java.util.Map;
public class ShoppingCart {
    private Map<String, Integer> cart;
    public ShoppingCart() {
    }
    public void addProduct(String productId, int quantity) {
    }
    public void removeProduct(String productId) throws Exception {
    }
    public boolean checkProductExists(String productId) {
        return false;
    }
}
```

import org.junit.Before;
import org.junit.Test;
import static org.junit.Assert.*;
public class ShoppingCartTest {
    private ShoppingCart cart;
    @Before
    public void setUp() {
        cart = new ShoppingCart();
    }
    @Test
    public void testAddProduct() {
        cart.addProduct("apple", 2);
        assertTrue(cart.checkProductExists("apple"));
    }
    @Test
    public void testAddMultipleProducts() {
        cart.addProduct("apple", 2);
        cart.addProduct("banana", 3);
        assertTrue(cart.checkProductExists("apple"));
        assertTrue(cart.checkProductExists("banana"));
    }
    @Test
    public void testRemoveProduct() throws Exception {
        cart.addProduct("apple", 2);
        cart.removeProduct("apple");
        assertFalse(cart.checkProductExists("apple"));
    }
    @Test(expected = Exception.class)
    public void testRemoveProductNotFound() throws Exception {
        cart.removeProduct("orange");
    }
    @Test
    public void testCheckProductExists() {
        cart.addProduct("banana", 3);
        assertTrue(cart.checkProductExists("banana"));
        assertFalse(cart.checkProductExists("apple"));
    }
}


import java.util.List;
import java.util.Arrays;
import java.util.ArrayList;
public class ProductTagValidator {
    private List<String> productTags;
    public ProductTagValidator(String... tags) {
        this.productTags = new ArrayList<>(Arrays.asList(tags));
    }
    public void validateTagsDoNotContain(String... tagsToCheck) throws IllegalArgumentException {
        if (tagsToCheck == null) {
            throw new IllegalArgumentException("标签数组不能为null");
        }
        for (String tag : tagsToCheck) {
            if (productTags.contains(tag)) {
                throw new IllegalArgumentException("商品的标签列表不应包含标签: " + tag);
            }
        }
    }
    public static void main(String[] args) {
        ProductTagValidator validator = new ProductTagValidator("电子", "书籍", "家具");
        try {
            validator.validateTagsDoNotContain("电子", "食品");
            System.out.println("验证通过，商品标签列表不包含指定的标签。");
        } catch (IllegalArgumentException e) {
            System.out.println(e.getMessage());
        }
    }
}

Please design a Java method that verifies whether a list of tags in a product object does not contain a specified set of tags. If the product's tag list contains any of these specified tags, the method should throw an exception.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.List;
import java.util.Arrays;
import java.util.ArrayList;
public class ProductTagValidator {
    private List<String> productTags;
    public ProductTagValidator(String... tags) {
    }
    public void validateTagsDoNotContain(String... tagsToCheck) throws IllegalArgumentException {
    }
}
```

import org.junit.Test;
import org.junit.Before;
import static org.junit.Assert.*;
import java.util.IllegalFormatException;
public class ProductTagValidatorTest {
    private ProductTagValidator validator;
    @Before
    public void setUp() {
        validator = new ProductTagValidator("电子", "书籍", "家具");
    }
    @Test(expected = IllegalArgumentException.class)
    public void testTagsDoNotContain_throwsException_whenTagIsContained() {
        validator.validateTagsDoNotContain("电子", "食品");
    }
    @Test
    public void testTagsDoNotContain_noException_whenTagsAreNotContained() {
        validator.validateTagsDoNotContain("食品", "玩具");
    }
    @Test(expected = IllegalArgumentException.class)
    public void testTagsDoNotContain_throwsException_whenOneTagIsContained() {
        validator.validateTagsDoNotContain("书籍");
    }
    @Test(expected = IllegalArgumentException.class)
    public void testTagsDoNotContain_throwsException_whenTagsToCheckIsNull() {
        validator.validateTagsDoNotContain((String[]) null);
    }
    @Test
    public void testTagsDoNotContain_noException_whenEmptyTagsToCheck() {
        validator.validateTagsDoNotContain();
    }
}


import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class FileToStringConverter {
    public static String fileContentToString(String filePath) throws IOException {
        StringBuilder contentBuilder = new StringBuilder();
        try (BufferedReader br = new BufferedReader(new FileReader(filePath))) {
            String currentLine;
            while ((currentLine = br.readLine()) != null) {
                contentBuilder.append(currentLine).append("\n");
            }
        }
        return contentBuilder.toString();
    }
    public static void main(String[] args) {
        try {
            String filePath = "example.txt";
            String content = fileContentToString(filePath);
            System.out.println(content);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Please write a Java method that can convert the content of a text file into a string. Ensure your method can handle large files and consider performance optimization when reading the file. Additionally, if the file does not exist or cannot be read, your method should throw an appropriate exception. Please follow the guidelines below to implement your solution:

- Use the necessary Java packages.
- Ensure the code snippet is entirely standalone and clear.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
public class FileToStringConverter {
    public static String fileContentToString(String filePath) throws IOException {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertThrows;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
public class FileToStringConverterTest {
    @Test
    public void testFileContentToString_validFile() throws IOException {
        Path tempFile = Files.createTempFile("testFile", ".txt");
        Files.write(tempFile, "line1\nline2\nline3".getBytes());
        String result = FileToStringConverter.fileContentToString(tempFile.toString());
        assertEquals("line1\nline2\nline3\n", result);
        Files.delete(tempFile);
    }
    @Test
    public void testFileContentToString_emptyFile() throws IOException {
        Path tempFile = Files.createTempFile("emptyFile", ".txt");
        String result = FileToStringConverter.fileContentToString(tempFile.toString());
        assertEquals("", result);
        Files.delete(tempFile);
    }
    @Test
    public void testFileContentToString_invalidFile() {
        assertThrows(IOException.class, () -> {
            FileToStringConverter.fileContentToString("non_existent_file.txt");
        });
    }
    @Test
    public void testFileContentToString_singleLineFile() throws IOException {
        Path tempFile = Files.createTempFile("singleLineFile", ".txt");
        Files.write(tempFile, "singleLine".getBytes());
        String result = FileToStringConverter.fileContentToString(tempFile.toString());
        assertEquals("singleLine\n", result);
        Files.delete(tempFile);
    }
    @Test
    public void testFileContentToString_fileWithNewLines() throws IOException {
        Path tempFile = Files.createTempFile("newLineFile", ".txt");
        Files.write(tempFile, "line1\n\nline2\n".getBytes());
        String result = FileToStringConverter.fileContentToString(tempFile.toString());
        assertEquals("line1\n\nline2\n", result);
        Files.delete(tempFile);
    }
}


import java.lang.System;
class Book {
    private String name;
    private String author;
    public void setBookInfo(String name, String author) {
        this.name = name;
        this.author = author;
    }
    public String getName() {
        return name;
    }
    public String getAuthor() {
        return author;
    }
}
public class BookManager {
    public void testSetBookInfo() {
        System.out.println("测试设置图书信息");
        Book book = new Book();
        book.setBookInfo("Java编程思想", "Bruce Eckel");
        System.out.println("书名: " + book.getName() + ", 作者: " + book.getAuthor());
    }
    public static void main(String[] args) {
        new BookManager().testSetBookInfo();
    }
}

Please design a Java program to manage book information. The specific requirements are as follows:

- There needs to be a `Book` class that includes two attributes: the book name (`name`) and the author (`author`).
- In the `Book` class, implement a method `setBookInfo` that takes two string parameters to set the book name and author.
- Additionally, there should be a `BookManager` class containing a method `testSetBookInfo` to test whether the `setBookInfo` method in the `Book` class can correctly set the book name and author.
- The `testSetBookInfo` method should print out the set book name and author to verify whether the setting was successful.
- Ensure all necessary packages are imported.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.lang.System;
class Book {
    private String name;
    private String author;
    public void setBookInfo(String name, String author) {
    }
    public String getName() {
        return null;
    }
    public String getAuthor() {
        return null;
    }
}
public class BookManager {
}
```

import static org.junit.jupiter.api.Assertions.assertEquals;
import org.junit.jupiter.api.Test;
class BookTest {
    @Test
    void testSetBookInfoAndGetters() {
        Book book = new Book();
        book.setBookInfo("Java编程思想", "Bruce Eckel");
        assertEquals("Java编程思想", book.getName());
        assertEquals("Bruce Eckel", book.getAuthor());
    }
    @Test
    void testSetBookInfoWithEmptyName() {
        Book book = new Book();
        book.setBookInfo("", "Bruce Eckel");
        assertEquals("", book.getName());
        assertEquals("Bruce Eckel", book.getAuthor());
    }
    @Test
    void testSetBookInfoWithEmptyAuthor() {
        Book book = new Book();
        book.setBookInfo("Java编程思想", "");
        assertEquals("Java编程思想", book.getName());
        assertEquals("", book.getAuthor());
    }
    @Test
    void testSetBookInfoWithNullName() {
        Book book = new Book();
        book.setBookInfo(null, "Bruce Eckel");
        assertEquals(null, book.getName());
        assertEquals("Bruce Eckel", book.getAuthor());
    }
    @Test
    void testSetBookInfoWithNullAuthor() {
        Book book = new Book();
        book.setBookInfo("Java编程思想", null);
        assertEquals("Java编程思想", book.getName());
        assertEquals(null, book.getAuthor());
    }
}


import java.util.Arrays;
public class ArrayAverageCalculator {
    public static double calculateAverage(int[] numbers) {
        if (numbers == null || numbers.length == 0) {
            return 0;
        }
        return Arrays.stream(numbers).average().orElse(0);
    }
    public static void check() {
        int[] testData1 = {1, 2, 3, 4, 5};
        int[] testData2 = {};
        int[] testData3 = {10, 20, 30, 40, 50};
        System.out.println("平均值 (应为3): " + calculateAverage(testData1));
        System.out.println("平均值 (应为0): " + calculateAverage(testData2));
        System.out.println("平均值 (应为30): " + calculateAverage(testData3));
    }
    public static void main(String[] args) {
        check();
    }
}

Please write a Java method to compute and return the average of all elements in an array. The method should accept an integer array as a parameter and return the calculated average. If the array is empty, it should return 0.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.Arrays;
public class ArrayAverageCalculator {
    public static double calculateAverage(int[] numbers) {
    }
    public static void check() {
    }
}
```

import org.junit.Assert;
import org.junit.Test;
public class ArrayAverageCalculatorTest {
    @Test
    public void testCalculateAverageWithPositiveNumbers() {
        int[] numbers = {1, 2, 3, 4, 5};
        double expected = 3.0;
        double actual = ArrayAverageCalculator.calculateAverage(numbers);
        Assert.assertEquals(expected, actual, 0.0001);
    }
    @Test
    public void testCalculateAverageWithEmptyArray() {
        int[] numbers = {};
        double expected = 0.0;
        double actual = ArrayAverageCalculator.calculateAverage(numbers);
        Assert.assertEquals(expected, actual, 0.0001);
    }
    @Test
    public void testCalculateAverageWithNullArray() {
        int[] numbers = null;
        double expected = 0.0;
        double actual = ArrayAverageCalculator.calculateAverage(numbers);
        Assert.assertEquals(expected, actual, 0.0001);
    }
    @Test
    public void testCalculateAverageWithAnotherSetOfPositiveNumbers() {
        int[] numbers = {10, 20, 30, 40, 50};
        double expected = 30.0;
        double actual = ArrayAverageCalculator.calculateAverage(numbers);
        Assert.assertEquals(expected, actual, 0.0001);
    }
    @Test
    public void testCalculateAverageWithSingleElement() {
        int[] numbers = {7};
        double expected = 7.0;
        double actual = ArrayAverageCalculator.calculateAverage(numbers);
        Assert.assertEquals(expected, actual, 0.0001);
    }
}


import java.util.ArrayList;
import java.util.List;
public class BookManager {
    static class Book {
        String title;
        String author;
        public Book(String title, String author) {
            this.title = title;
            this.author = author;
        }
    }
    private List<Book> books;
    public BookManager() {
        this.books = new ArrayList<>();
    }
    public void addBook(String title, String author) {
        books.add(new Book(title, author));
    }
    public String findAuthorByTitle(String title) {
        for (Book book : books) {
            if (book.title.equals(title)) {
                return book.author;
            }
        }
        return "书籍不存在";
    }
    public static void main(String[] args) {
        BookManager manager = new BookManager();
        manager.addBook("Java编程思想", "Bruce Eckel");
        manager.addBook("Effective Java", "Joshua Bloch");
        System.out.println(manager.findAuthorByTitle("Java编程思想"));
        System.out.println(manager.findAuthorByTitle("未知书籍"));
    }
}

Please write a Java program to manage book information in a library. The specific requirements are as follows:

- There needs to be a method to add book information to a list. Each book's information includes the book title and author name.
- Another method is required to search by book title and return the author's name. If the book does not exist, it should return a specific message, such as "Book not found."

Ensure that your code is completely self-contained and that all packages used are imported at the beginning of the code snippet.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.ArrayList;
import java.util.List;
public class BookManager {
    static class Book {
        String title;
        String author;
        public Book(String title, String author) {
        }
    }
    private List<Book> books;
    public BookManager() {
    }
    public void addBook(String title, String author) {
    }
    public String findAuthorByTitle(String title) {
    }
}
```

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class BookManagerTest {
    private BookManager manager;
    @BeforeEach
    public void setUp() {
        manager = new BookManager();
    }
    @Test
    public void testAddBook() {
        manager.addBook("Java编程思想", "Bruce Eckel");
        assertEquals("Bruce Eckel", manager.findAuthorByTitle("Java编程思想"));
    }
    @Test
    public void testFindAuthorByTitle_ExistingBook() {
        manager.addBook("Java编程思想", "Bruce Eckel");
        String author = manager.findAuthorByTitle("Java编程思想");
        assertEquals("Bruce Eckel", author);
    }
    @Test
    public void testFindAuthorByTitle_NonExistingBook() {
        manager.addBook("Java编程思想", "Bruce Eckel");
        String author = manager.findAuthorByTitle("未知书籍");
        assertEquals("书籍不存在", author);
    }
    @Test
    public void testAddMultipleBooks() {
        manager.addBook("Java编程思想", "Bruce Eckel");
        manager.addBook("Effective Java", "Joshua Bloch");
        assertEquals("Joshua Bloch", manager.findAuthorByTitle("Effective Java"));
    }
    @Test
    public void testFindAuthorByTitle_CaseSensitive() {
        manager.addBook("Java编程思想", "Bruce Eckel");
        String author = manager.findAuthorByTitle("java编程思想");
        assertEquals("书籍不存在", author);
    }
}


import java.util.ArrayList;
import java.util.List;
public class BookManager {
    private List<Book> books = new ArrayList<>();
    public String addBook(String title, String author, String isbn, int year) {
        Book newBook = new Book(title, author, isbn, year);
        books.add(newBook);
        return "Book added successfully!";
    }
    public static void main(String[] args) {
        BookManager manager = new BookManager();
        String result = manager.addBook("Java Programming", "John Doe", "123456789", 2020);
        System.out.println(result);
    }
    private static class Book {
        String title;
        String author;
        String isbn;
        int year;
        public Book(String title, String author, String isbn, int year) {
            this.title = title;
            this.author = author;
            this.isbn = isbn;
            this.year = year;
        }
    }
}

Please write a Java method for adding new book information in a simple book management system. The method should take the book's title, author, ISBN number, and publication year as parameters and save this information in the system. Ensure that your code handles the basic logic of adding a book and can return a message indicating that the book has been successfully added.

Please follow these guidelines to complete this task:

- The problem description should be as concise and fluent as possible.
- The code snippet should be entirely self-contained and clear.
- The code must import all used packages at the beginning.
- Try to make the code snippet different from the given code snippet (including class names, function names, docstrings, and variable names).
- The problem and solution should be written in Chinese (the code implementation must not use Chinese, code comments should be in English).
Please implement complete code in Java that does not include the Main function, and follow the type definitions below:

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
import java.util.ArrayList;
import java.util.List;
public class BookManagerTest {
    @Test
    public void testAddBook_ValidDetails_ReturnsSuccessMessage() {
        BookManager manager = new BookManager();
        String result = manager.addBook("Effective Java", "Joshua Bloch", "9780134685991", 2018);
        assertEquals("Book added successfully!", result);
    }
    @Test
    public void testAddBook_TitleIsEmpty_ReturnsSuccessMessage() {
        BookManager manager = new BookManager();
        String result = manager.addBook("", "Unknown Author", "0000000000", 2021);
        assertEquals("Book added successfully!", result);
    }
    @Test
    public void testAddBook_AuthorNameIsEmpty_ReturnsSuccessMessage() {
        BookManager manager = new BookManager();
        String result = manager.addBook("Unknown Title", "", "0000000000", 2021);
        assertEquals("Book added successfully!", result);
    }
    @Test
    public void testAddBook_EmptyISBN_ReturnsSuccessMessage() {
        BookManager manager = new BookManager();
        String result = manager.addBook("Some Book", "Some Author", "", 2022);
        assertEquals("Book added successfully!", result);
    }
    @Test
    public void testAddBook_YearZero_ReturnsSuccessMessage() {
        BookManager manager = new BookManager();
        String result = manager.addBook("Ancient Book", "Ancient Author", "1111111111", 0);
        assertEquals("Book added successfully!", result);
    }
    private static class BookManager {
        private List<Book> books = new ArrayList<>();
        public String addBook(String title, String author, String isbn, int year) {
            Book newBook = new Book(title, author, isbn, year);
            books.add(newBook);
            return "Book added successfully!";
        }
    }
    private static class Book {
        String title;
        String author;
        String isbn;
        int year;
        public Book(String title, String author, String isbn, int year) {
            this.title = title;
            this.author = author;
            this.isbn = isbn;
            this.year = year;
        }
    }
}


import java.util.HashMap;
import java.util.Map;
public class BookFinder {
    private Map<Integer, String> books;
    public BookFinder() {
        books = new HashMap<>();
        books.put(1, "Java编程思想");
        books.put(2, "Effective Java");
        books.put(3, "深入理解Java虚拟机");
    }
    public String findBookNameById(int bookId) {
        return books.getOrDefault(bookId, "未找到");
    }
    public static void main(String[] args) {
        BookFinder finder = new BookFinder();
        check(finder.findBookNameById(1), "Java编程思想");
        check(finder.findBookNameById(4), "未找到");
    }
    private static void check(String actual, String expected) {
        if (actual.equals(expected)) {
            System.out.println("测试通过");
        } else {
            System.out.println("测试失败");
        }
    }
}

Please describe how a Java program could implement a simple book management system's book search function. In this system, each book has a unique ID and a title. You need to explain the method that searches for the title of a book by its ID. If a book with the corresponding ID is found, indicate how the title can be returned; if not found, specify a way to indicate it was not found. Describe how the program could be self-contained and include all necessary import statements.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.HashMap;
import java.util.Map;
public class BookFinder {
    private Map<Integer, String> books;
    public BookFinder() {
    }
    public String findBookNameById(int bookId) {
    }
}
```

import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.Test;
public class BookFinderTest {
    @Test
    public void testFindBookNameById_bookExists() {
        BookFinder finder = new BookFinder();
        Assertions.assertEquals("Java编程思想", finder.findBookNameById(1));
    }
    @Test
    public void testFindBookNameById_bookExists2() {
        BookFinder finder = new BookFinder();
        Assertions.assertEquals("Effective Java", finder.findBookNameById(2));
    }
    @Test
    public void testFindBookNameById_bookExists3() {
        BookFinder finder = new BookFinder();
        Assertions.assertEquals("深入理解Java虚拟机", finder.findBookNameById(3));
    }
    @Test
    public void testFindBookNameById_bookNotExists() {
        BookFinder finder = new BookFinder();
        Assertions.assertEquals("未找到", finder.findBookNameById(4));
    }
    @Test
    public void testFindBookNameById_bookNotExistsNegative() {
        BookFinder finder = new BookFinder();
        Assertions.assertEquals("未找到", finder.findBookNameById(-1));
    }
}


import java.util.logging.Logger;
public class DatabaseErrorChecker {
    private static final Logger logger = Logger.getLogger(DatabaseErrorChecker.class.getName());
    public static void checkDbError(String operation, int errorCode) {
        if (errorCode != 0) {
            String errorMessage = operation + ": DbError " + errorCode;
            logger.severe(errorMessage);
            throw new DatabaseOperationException(errorMessage);
        }
    }
    public static void main(String[] args) {
        try {
            checkDbError("UpdateUser", 1001);
        } catch (DatabaseOperationException e) {
            System.out.println("Caught exception: " + e.getMessage());
        }
    }
}
class DatabaseOperationException extends RuntimeException {
    public DatabaseOperationException(String message) {
        super(message);
    }
}

Please write a Java method to check for errors in database operations and log the error information. If an error is found, the method should throw an exception containing the operation name and specific error code. Ensure your method is self-contained and imports the necessary packages.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.logging.Logger;
public class DatabaseErrorChecker {
    private static final Logger logger = Logger.getLogger(DatabaseErrorChecker.class.getName());
    public static void checkDbError(String operation, int errorCode) {
    }
}
class DatabaseOperationException extends RuntimeException {
    public DatabaseOperationException(String message) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class DatabaseErrorCheckerTest {
    @Test
    public void testCheckDbErrorWithNoError() {
        assertDoesNotThrow(() -> DatabaseErrorChecker.checkDbError("SelectUser", 0));
    }
    @Test
    public void testCheckDbErrorWithError() {
        DatabaseOperationException exception = assertThrows(DatabaseOperationException.class, () -> {
            DatabaseErrorChecker.checkDbError("UpdateUser", 1001);
        });
        assertEquals("UpdateUser: DbError 1001", exception.getMessage());
    }
    @Test
    public void testCheckDbErrorAnotherOperationWithError() {
        DatabaseOperationException exception = assertThrows(DatabaseOperationException.class, () -> {
            DatabaseErrorChecker.checkDbError("DeleteUser", 1002);
        });
        assertEquals("DeleteUser: DbError 1002", exception.getMessage());
    }
    @Test
    public void testCheckDbErrorWithZeroErrorCode() {
        assertDoesNotThrow(() -> DatabaseErrorChecker.checkDbError("InsertUser", 0));
    }
    @Test
    public void testCheckDbErrorWithNegativeErrorCode() {
        DatabaseOperationException exception = assertThrows(DatabaseOperationException.class, () -> {
            DatabaseErrorChecker.checkDbError("FetchUser", -1);
        });
        assertEquals("FetchUser: DbError -1", exception.getMessage());
    }
}


import java.util.Arrays;
public class CoordinateMapper {
    public static long[] map3DPoint(double longitude, double minLongitude, double maxLongitude,
                                    double latitude, double minLatitude, double maxLatitude,
                                    double timestamp, double minTimestamp, double maxTimestamp,
                                    long maxValue) {
        long x = mapValue(longitude, minLongitude, maxLongitude, maxValue);
        long y = mapValue(latitude, minLatitude, maxLatitude, maxValue);
        long z = mapValue(timestamp, minTimestamp, maxTimestamp, maxValue);
        return new long[]{x, y, z};
    }
    private static long mapValue(double value, double minValue, double maxValue, long targetMaxValue) {
        return Math.round((value - minValue) / (maxValue - minValue) * targetMaxValue);
    }
    public static void main(String[] args) {
        double longitude = 116.4074, minLongitude = 116.0, maxLongitude = 117.0;
        double latitude = 39.9042, minLatitude = 39.0, maxLatitude = 40.0;
        double timestamp = 1588000000, minTimestamp = 1587000000, maxTimestamp = 1589000000;
        long maxValue = 1000;
        long[] mappedCoordinates = map3DPoint(longitude, minLongitude, maxLongitude, latitude, minLatitude, maxLatitude, timestamp, minTimestamp, maxTimestamp, maxValue);
        System.out.println("映射后的坐标: " + Arrays.toString(mappedCoordinates));
    }
}

Please write a Java method to map the coordinates of a 3D point (longitude, latitude, time) into a new 3D coordinate system. The maximum value of each dimension in the new coordinate system is specified by the user. Specifically, you need to map the original 3D point to a new coordinate system where the minimum value is 0, and the maximum value is the user-specified maximum, based on the given minimum and maximum values of the longitude, latitude, and time. Ensure that your method can handle various inputs and returns a long array containing the mapped x, y, z coordinates.
Please use Java to implement the complete code without the Main function. Please follow the following type definitions:

```java
import java.util.Arrays;
public class CoordinateMapper {
    public static long[] map3DPoint(double longitude, double minLongitude, double maxLongitude,
                                    double latitude, double minLatitude, double maxLatitude,
                                    double timestamp, double minTimestamp, double maxTimestamp,
                                    long maxValue) {
    }
    private static long mapValue(double value, double minValue, double maxValue, long targetMaxValue) {
    }
}
```

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class CoordinateMapperTest {
    @Test
    public void testMap3DPoint_withinBounds() {
        double longitude = 116.4074, minLongitude = 116.0, maxLongitude = 117.0;
        double latitude = 39.9042, minLatitude = 39.0, maxLatitude = 40.0;
        double timestamp = 1588000000, minTimestamp = 1587000000, maxTimestamp = 1589000000;
        long maxValue = 1000;
        long[] result = CoordinateMapper.map3DPoint(longitude, minLongitude, maxLongitude,
                                                     latitude, minLatitude, maxLatitude,
                                                     timestamp, minTimestamp, maxTimestamp,
                                                     maxValue);
        assertArrayEquals(new long[]{407, 904, 500}, result);
    }
    @Test
    public void testMap3DPoint_edgeValues() {
        double longitude = 116.0, minLongitude = 116.0, maxLongitude = 117.0;
        double latitude = 40.0, minLatitude = 39.0, maxLatitude = 40.0;
        double timestamp = 1587000000, minTimestamp = 1587000000, maxTimestamp = 1589000000;
        long maxValue = 1000;
        long[] result = CoordinateMapper.map3DPoint(longitude, minLongitude, maxLongitude,
                                                     latitude, minLatitude, maxLatitude,
                                                     timestamp, minTimestamp, maxTimestamp,
                                                     maxValue);
        assertArrayEquals(new long[]{0, 1000, 0}, result);
    }
    @Test
    public void testMap3DPoint_midRangeValues() {
        double longitude = 116.5, minLongitude = 116.0, maxLongitude = 117.0;
        double latitude = 39.5, minLatitude = 39.0, maxLatitude = 40.0;
        double timestamp = 1588000000, minTimestamp = 1587000000, maxTimestamp = 1589000000;
        long maxValue = 1000;
        long[] result = CoordinateMapper.map3DPoint(longitude, minLongitude, maxLongitude,
                                                     latitude, minLatitude, maxLatitude,
                                                     timestamp, minTimestamp, maxTimestamp,
                                                     maxValue);
        assertArrayEquals(new long[]{500, 500, 500}, result);
    }
    @Test
    public void testMap3DPoint_minValues() {
        double longitude = 116.0, minLongitude = 116.0, maxLongitude = 117.0;
        double latitude = 39.0, minLatitude = 39.0, maxLatitude = 40.0;
        double timestamp = 1587000000, minTimestamp = 1587000000, maxTimestamp = 1589000000;
        long maxValue = 1000;
        long[] result = CoordinateMapper.map3DPoint(longitude, minLongitude, maxLongitude,
                                                     latitude, minLatitude, maxLatitude,
                                                     timestamp, minTimestamp, maxTimestamp,
                                                     maxValue);
        assertArrayEquals(new long[]{0, 0, 0}, result);
    }
    @Test
    public void testMap3DPoint_maxValues() {
        double longitude = 117.0, minLongitude = 116.0, maxLongitude = 117.0;
        double latitude = 40.0, minLatitude = 39.0, maxLatitude = 40.0;
        double timestamp = 1589000000, minTimestamp = 1587000000, maxTimestamp = 1589000000;
        long maxValue = 1000;
        long[] result = CoordinateMapper.map3DPoint(longitude, minLongitude, maxLongitude,
                                                     latitude, minLatitude, maxLatitude,
                                                     timestamp, minTimestamp, maxTimestamp,
                                                     maxValue);
        assertArrayEquals(new long[]{1000, 1000, 1000}, result);
    }
}