zoukankan      html  css  js  c++  java
  • 09异常处理

    动手动脑一:

             代码:

                       import javax.swing.*;

    class AboutException {

                   public static void main(String[] a)

                              {

                int i=1, j=0, k;//double可以被0整除,整数和浮点型运算不一样

          k=i/j;

             try

             {

                      

                       k = i/j;    // Causes division-by-zero exception

                       //throw new Exception("Hello.Exception!");

             }

            

             catch ( ArithmeticException e)

             {

                       System.out.println("被0除.  "+ e.getMessage());

             }

            

             catch (Exception e)

             {

                       if (e instanceof ArithmeticException)

                                System.out.println("被0除");

                       else

                       { 

                                System.out.println(e.getMessage());

                               

                       }

             }

            

             finally

         {

                         JOptionPane.showConfirmDialog(null,"OK"+k);

         }

                      

      }

    }

    结论:

    Try{

                                //可能发生运行错误的代码;

                       }

                       catch(异常类型     异常对象引用){

                                //用于处理异常的代码

                       }

                       finally{

                                //用于“善后” 的代码

                       }

    动手动脑二:

    截图:

    动手动脑三:

    截图:

    动手动脑四:

    代码:

    public class EmbededFinally {

     

       

             public static void main(String args[]) {

           

                       int result;

           

                       try {

               

                                System.out.println("in Level 1");

     

              

                               try {

                   

                                         System.out.println("in Level 2");

      // result=100/0;  //Level 2

                  

                                        try {

                      

                                                 System.out.println("in Level 3");

                         

                                                 result=100/0;  //Level 3

                   

                                         }

                   

                                         catch (Exception e) {

                       

                                                   System.out.println("Level 3:" + e.getClass().toString());

                   

                                         }

                   

                   

                                         finally {

                       

                                                   System.out.println("In Level 3 finally");

                   

                                         }

                    

                  

                                         // result=100/0;  //Level 2

     

               

                                         }

               

                                catch (Exception e) {

                  

                                        System.out.println("Level 2:" + e.getClass().toString());

              

                               }

                               finally {

                   

                                         System.out.println("In Level 2 finally");

              

                                 }

                

                                // result = 100 / 0;  //level 1

           

                       }

           

                       catch (Exception e) {

               

                                System.out.println("Level 1:" + e.getClass().toString());

           

                       }

           

                       finally {

              

                     System.out.println("In Level 1 finally");

           

                       }

       

             }

     

    }

    截图:

    总结:在一个方法体中finally执行的是相对应的catch的内容

    动手动脑五:

    代码:

     

    public class SystemExitAndFinally {

     

       

             public static void main(String[] args)

        {

           

                       try{

     

               

                                System.out.println("in main");

               

                                throw new Exception("Exception is thrown in main");

     

                                   //System.exit(0);

     

           

                       }

           

                       catch(Exception e)

     

                     {

               

                                System.out.println(e.getMessage());

               

                                System.exit(0);

           

                       }

           

                       finally

           

                       {

               

                                System.out.println("in finally");

           

                       }

             }

    }

    截图:

    总结:当catch中有exit退出程序时,这时就不在执行finally

  • 相关阅读:
    Mysql:用户操作命令
    Cookie和Set-Cookie
    Matcher中appendReplacement()方法与replaceAll()方法的联系
    记录一次mysql执行异常(磁盘空间)
    ehcache简单配置
    md5
    mysql后台运行简单的备份脚本
    shell脚本研习
    SpringBoot根据条件,去注入需要的Bean
    springboot后台跨域设置
  • 原文地址:https://www.cnblogs.com/shouhutian/p/6102832.html
Copyright © 2011-2022 走看看