java 异常

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;

public class Test3 {
    public static void main(String[] args) {
        //异常分类  1.编译期  2.运行期
        //

        SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd");
        Date parse = null;
        try {
            parse = simpleDateFormat.parse("2021-3-3");  //parse 需要捕捉，不然编译报错
        } catch (ParseException e) {
            e.printStackTrace();
        }
        System.out.println(parse);


        int i = 1 / 0; // by zero
        int[] arr = {1, 2, 3,};
        System.out.println(arr[3]);//下标：0  1  2，无3

        System.out.println("hello,world");
    }
}

public class Test4 {
    public static void main(String[] args) {
        //自定义异常，这只是个例子
        try {
            TestE testE = new TestE();
            testE.do1();
        } catch (MyExcetion e) {
            e.printStackTrace();
        }

        System.out.println("hello,world");
    }

    public static class TestE {
        public void do1() throws MyExcetion {
            throw new MyExcetion("123");
        }
    }

    public static class MyExcetion extends Exception {
        public MyExcetion() {
            super();
        }

        public MyExcetion(String msg) {
            super("MyExcetion:" + msg);
        }
    }
}