Java培训总结笔记（三）

throw new ArrayIndexOutOfBoundsException();
   //手动抛出;JVM运行时帮你抛出

public class Launcher {
    public static void main(String[] args){
        m1();
    }
    public static void m1(){
        m2();
    }
    public static void m2(){
        int[] arr = new int[2];
        arr[2] =1;
    }
}
/*Exception in thread "main" java.lang.ArrayIndexOutOfBoundsException: 2
at Launcher.m2(Launcher.java:13)
at Launcher.m1(Launcher.java:9)
at Launcher.main(Launcher.java:6)
*/

public class Launcher {
    public static void main(String[] args){
        try{
            m1();
        }catch(ArrayIndexOutOfBoundsException e){
            e.printStackTrace();
        }catch(Exception e){
            e.printStackTrace();
        }finally{
            System.out.println("finally");
        }
    }
    public static void m1(){
        m2();
    }
    public static void m2(){
        int[] arr = new int[2];
        arr[2] =1;
    }
}
//catch可以有多个，顺序从小到大

public class MyException extends Exception //继承自Exception
{
    public MyException(){
        super();
    }
    public MyException(String msg){
        super(msg);
    }
}
public static void main(String[] args)throws MyException{
    throw new MyException("出现异常了");
    //throw new NullPointerException();
    }