我刚学习Java中的异常处理.我想知道的不是尝试说：

throw new Exception("My Message");

和

String message=ex.getMessage();

System.out.println(message);

看看下面的代码,

class ExceptionTest {
    public static void main(String[] args) {
        ExceptionTest t1=new ExceptionTest();

        try {
            t1.riskyMethod();//call the risky or exception throwing method
        } catch(MyException myex) {
            System.out.println("Exception has been thrown");

            String message=myex.getMessage();//get the String passed during exception call
            System.out.println("The message retrieved is "+message);
            myex.printStackTrace();//prints name of exception and traces the function call stack
        }

    }//main ends

    void riskyMethod() throws MyException {//a method that can throw an excpetion
        int rand=(int)(Math.random()*10);///Math.rand return 0 to .9 range value

        if(rand>5) {
            //throw new MyException();  or try this
            //      MyException myexception=new MyException();
            //      myexception.setMessage("HI THIS IS A SAMPLE MESSAGE");
            String mymessage="Sample Exception Message...";
            throw new MyException(mymessage);
        }
        else
            System.out.println("No exception");
    }
}//Exception class ends 

虽然这很好,我想知道我是否可以避免调用超级(消息)等
并在我的子类MyException中设置一些变量’message’,它更改在调用exception.getMessage()时检索到的消息

换句话说,存储传递给构造函数的消息字符串的字符串变量的名称是什么,我可以手动设置它,是最终的还是私有的,如果有的话,有任何setter方法.对不起,我试过,但我只是一个初学者,无法浏览API

解决方法:

不,没有办法手动设置消息,但是你可以只使用自己的变量并覆盖getMessage()方法

例：

public class MyException extends Exception{

    public String message;

    public MyException(String message){
        this.message = message;
    }

    // Overrides Exception's getMessage()
    @Override
    public String getMessage(){
        return message;
    }

    // Testing
    public static void main(String[] args){
        MyException e = new MyException("some message");
        System.out.println(e.getMessage());
    }


}