Java声明异常，抛出异常

import java.text.ParseException;
import java.text.SimpleDateFormat;


public class Throw {
    public static void main(String[] args) {
		//会报错
        int[] arr ={1,2,3,4,5};
        System.out.println(arr[10]); //越界
        // ArrayIndexOutOfBoundsException
		
		//throw ，throws
        method1(); //空指针异常
        int[] arr_AIOBE ={};
        int max = getMax(arr_AIOBE);

    }

    //throws是告诉系统可能存在的异常,警告其小心一点!
    private static void method1() throws NullPointerException {
        int[] arr =null;
        for (int i = 0; i < arr.length; i++) {
            System.out.println(arr[i]);
        }
    }
}

    public static int getMax(int[] arr)
    {
        if(arr.length==0 || arr == null)
        {
            System.out.println("Error!");
            throw  new RuntimeException();
            //有不正常操作,造一个异常来终止操作!
        }
        int max = arr[0];
        for (int i = 0; i < arr.length; i++) {
            if(arr[i]> max)
            {
                max = arr[i];
            }
        }
        return  max;

    }