关于Java异常的疑问

Question

众所周知下面的代码编译不过：

public class test{
    private static void haha(){
        throw new Exception();
    }
    public static void main(String[] args) {
        haha();
        return;
    }
}

javac test.java

未报告的异常错误Exception; 必须对其进行捕获或声明以便抛出。

但是下面的代码没有进行错误处理，却能够通过编译：

public class test{
    public static void main(String[] args) {
        String s = new String("test");
        System.out.println(s.substring(0,6));
        return;
    }
}

javac test.java
java test

Exception in thread "main" java.lang.StringIndexOutOfBoundsException: String index out of range: 6
        at java.lang.String.substring(Unknown Source)
        at test.main(test.java:4)

请问这是什么原因？

Answer 1

StringIndexOutOfBoundsException inherits RuntimeException and does not need to be explicitly processed.

Answer 2

The first exception thrown is a checked exception, which is a compiler exception, so it must be handled manually. The second thrown StringIndexOutOfBoundsException is an unchecked exception and a runtime exception, so there is no need to handle it manually