怎样抛出自己定义的异常

 继承Exception类

public class MyFirstException extends Exception{

    public MyFirstException(){
        
    }
    public MyFirstException(String msg){
        super(msg);
    }
    public MyFirstException(String msg,Throwable cause){
        super(msg,cause);
    }
    public MyFirstException(Throwable cause){
        super(cause);
    }
    
}

继承Throwable类

public class MySecondException extends Throwable{

    public MySecondException(){
        
    }
    public MySecondException(String msg){
        super(msg);
    }
    public MySecondException(String msg,Throwable cause){
        super(msg,cause);
    }
    public MySecondException(Throwable cause){
        super(cause);
    }
    
}

插曲：

方法里中有throw的时候，方法名一定要有throws抛出异常

 果然第一行抛出异常后就停止了，第二行TestOneTwoException.secondException()没有执行

回来：

1.要有自己定义的异常类

2.要有方法抛出了这个异常，下面的firstException()和secondException()

3.有调用这个方法TestOneTwoException.firstException()

public class TestOneTwoException {

    public static void firstException() throws MyFirstException{
        throw new MyFirstException("First异常");
    }
    
    public static void secondException() throws MySecondException{
        throw new MySecondException("Second异常");
    }
    
    public static void main(String[] args) {
        try {
            TestOneTwoException.firstException();
        } catch (MyFirstException e) {
            // TODO: handle exception
            System.out.println("11111"+e);
        } 
        
        
        try {
            TestOneTwoException.secondException();
        }catch(MySecondException e){
            
            System.out.println("22222"+e);
            
        }
    }
    
    
    
    
}