Java Custom Exceptions Guide

In Java, there are several steps to customize exceptions.

1. Create a class that inherits from the Exception class or a subclass, serving as a custom exception class.
2. In a custom exception class, you can define a constructor method and add parameters as needed.
3. You can use the keyword “super” to call the constructor of the parent class in the constructor method.
4. You can add additional methods or properties in a custom exception class to meet specific exception handling needs.

Here is an example code:

public class MyException extends Exception {

    public MyException() {
        super();
    }

    public MyException(String message) {
        super(message);
    }

    public MyException(String message, Throwable cause) {
        super(message, cause);
    }

    public MyException(Throwable cause) {
        super(cause);
    }

    // 其他方法或属性
}

When using custom exceptions, you can choose the appropriate constructor method to create and throw an exception as needed. For example:

public class MyClass {

    public void myMethod() throws MyException {
        // 某些操作发生异常时，抛出自定义异常
        throw new MyException("发生了自定义异常");
    }
}

When calling the myMethod() method, a custom exception will be thrown if an error occurs, and the exception can be handled in the catch block.