Java中的自定义异常实现方式

public class MyCustomException extends Exception {
    public MyCustomException() {
        super();
    }
    public MyCustomException(String message) {
        super(message);
    }
    // 可选：带原因（Throwable）的构造器
    public MyCustomException(String message, Throwable cause) {
        super(message, cause);
    }
}

public class BusinessException extends RuntimeException {
    private int errorCode;

    public BusinessException(int errorCode, String message) {
        super(message);
        this.errorCode = errorCode;
    }
    public int getErrorCode() {
        return errorCode;
    }
}

public void validateAge(int age) throws InvalidAgeException {
    if (age < 0) {
        throw new InvalidAgeException("年龄不能为负数");
    }
}

// 调用处
try {
    validateAge(-1);
} catch (InvalidAgeException e) {
    System.err.println("错误信息：" + e.getMessage());
}

public class InsufficientBalanceException extends RuntimeException {
    public InsufficientBalanceException(String message) {
        super(message);
    }
}

// 使用场景
public void withdraw(double amount) {
    if (amount > balance) {
        throw new InsufficientBalanceException("余额不足，当前余额：" + balance);
    }
}

// 根异常
public class BaseException extends RuntimeException {
    private String code;

    public BaseException(String code, String message) {
        super(message);
        this.code = code;
    }
    public String getCode() { return code; }
}

// 子类异常
public class UserNotFoundException extends BaseException {
    public UserNotFoundException() {
        super("USER_404", "用户不存在");
    }
}

throw new ValidationException("参数 %s 的值 %d 超出范围", "age", 150);

try {
    // 可能抛出IOException的代码
} catch (IOException e) {
    throw new DataLoadException("加载数据失败", e); // 传递原始异常
}