这个程序给我一个无限的菜单（do-while）

Question

我是新来的。我试图运行一个程序，每当我尝试执行它时总会给我一个无限的菜单循环。任何帮助将不胜感激。

public void show()throws IOException 
{ 
        BufferedReader z=new BufferedReader(new InputStreamReader(System.in)); 
        int ch; 
        input(); 
        calculate(); 

         System.out.println(" 1.Print the names of Employees having more than average salary"); 
         System.out.println(" 2.Find the maximum and minimum gross salary "); 
         System.out.println(" 3.To find the net salaries of employees in ascending order"); 
         System.out.println(" 4.To print the name of employee having the longest name"); 
         System.out.println(" 5.To find the reverse names of the employees"); 
         System.out.println(" 6.To find the reverse of employee's name"); 
         System.out.println(" 7.Exit"); 
         System.out.println("Enter your choice"); 
         ch=Integer.parseInt(z.readLine()); 


         switch(ch) 
         { 
          case 1:calc_avg(); 
          break; 
          case 2:max_and_min(); 
          break; 
          case 3:sort(); 
          break; 
          case 4:vowel(); 
          break; 
          case 5:longest(); 
          break; 
          case 6:reverse_name(); 
          break; 
          case 7: 
          System.out.println("Close"); 
          break; 
          default:System.out.println("Wrong choice ! "); 
          } 
          } 
          while(ch>=1&&ch<=7); 

}}

这总是给我一个无限循环。我该如何解决 ？

Answer 1

下面是如何正确地做;）

public void show()throws IOException { 
     BufferedReader z=new BufferedReader(new InputStreamReader(System.in)); 
     int ch=0; 
     input(); 
     calculate(); 
     System.out.println(" 1.Print the names of Employees having more than average salary"); 
     System.out.println(" 2.Find the maximum and minimum gross salary "); 
     System.out.println(" 3.To find the net salaries of employees in ascending order"); 
     System.out.println(" 4.To print the name of employee having the longest name"); 
     System.out.println(" 5.To find the reverse names of the employees"); 
     System.out.println(" 6.To find the reverse of employee's name"); 
     System.out.println(" 7.Exit"); 
     System.out.println("Enter your choice :"); 
     ch=Integer.parseInt(z.readLine()); 
     while(!(ch>=1&&ch<=7)){ 
      System.out.println("Wrong choice ! Please enter a good choice :"); 
      ch=Integer.parseInt(z.readLine()); 
     } 

     switch(ch){ 
     case 1: 
      calc_avg(); 
      break; 
     case 2: 
      max_and_min(); 
      break; 
     case 3: 
      sort(); 
      break; 
     case 4: 
      vowel(); 
      break; 
     case 5: 
      longest(); 
      break; 
     case 6: 
      reverse_name(); 
      break; 
     case 7: 
      System.out.println("Close"); 
      break; 
     } 
    }