异常处理：

①捕获异常

选中代码后ctrl+Alt+t:

try catch捕捉异常

②抛出异常

加上throws  异常类型

 自定义异常

 Exception.java:

package Exception;

//自定义运行时异常
public class ExceptionTest {
    public static void main(String[] args) {
        //保存一个合法的年龄

        try {
            saveAge(160);
            System.out.println("底层执行成功");
        } catch (Exception e) {
            e.printStackTrace();//输出异常信息
            System.out.println("底层执行失败");
        }
    }

    public static void saveAge(int age){
        if (age < 0 && age < 150) {
            System.out.println("年龄被成功保存："+age);
        }else{
            //用一个异常对象封装这个问题
            //throw抛出这个异常对象
            throw new AgeIllegalRunTimrException("age is illegal ,your age is " + age);
        }
    }
}

AgeIllegalRunTimrException.java:

package Exception;

//必须让这个类继承RuntimeException
public class AgeIllegalRunTimrException extends RuntimeException{
    public AgeIllegalRunTimrException(String message) {
        super(message);
    }

    public AgeIllegalRunTimrException() {
    }
}

输出：

Exception.AgeIllegalRunTimrException: age is illegal ,your age is 160
	at Exception.ExceptionTest.saveAge(ExceptionTest.java:21)
	at Exception.ExceptionTest.main(ExceptionTest.java:9)
底层执行失败