java----异常处理

public class Demo {
    public static void main(String[] args){    	
    	test();
    }
    public static void test(){
    	int[] arr = {1,2,3};
    	try{
    		System.out.print(arr[8]);
    	}catch(ArrayIndexOutOfBoundsException e){
    		System.out.println(e);
    	}
    	catch(Exception e){
    		e.printStackTrace(); //可以打印栈错误信息
    		System.out.println("错误");
    	}finally{
    		System.out.println("无论是否产生异常,都要执行");//即使系统报错,程序会异常退出,也会执行,即使try中有return,finally也会在return之前执行
    	}
    }
}

public class Demo {
    public static void main(String[] args){    	
    	test();
    }
    public static int test() throws ArrayIndexOutOfBoundsException{
    	Scanner s = new Scanner(System.in);
    	try{
    		int[] arr = {1,2};
    		int x = arr[4];
    		return 1;
    	}catch(ArrayIndexOutOfBoundsException e){
//    		e.printStackTrace();
    		throw new ArrayIndexOutOfBoundsException("出错了");//主动抛出错误
//    		return 1;
    	}
    }
}