try{}catch{}finally{}使用总结

 1 import java.util.Scanner;
 2 
 3 
 4 class MyException extends Exception
 5 {
 6     public MyException(String Message) {
 7         super(Message);
 8     }
 9     public MyException(String message, Throwable cause) {
10         super(message, cause);
11     }
12     public MyException( Throwable cause) {
13         super(cause);
14     }
15 
16 }
17 
18 public class Juage {
19     public static void main(String[] args){
20         Scanner scan=new Scanner(System.in);
21         try {
22             int a = scan.nextInt();
23             if(a<0||a>100) {System.out.println("输入有误") ;}
24             else {
25                 if(a<60) System.out.println("不及格");
26                 if(a>=60&&a<70) System.out.println("及格");
27                 if(a>=70&&a<80) System.out.println("中");
28                 if(a>=80&&a<90) System.out.println("良");
29                 if(a>=90&&a<100) System.out.println("优");
30             }
31         }
32         catch (Exception e){
33             MyException mec=new MyException("输入有误",e);
34             System.err.println(e.toString());
35         }
36 
37     }
38 }