Java输入不匹配异常处理

Question

我正在处理输入输出异常处理问题，我正在为类编写库存管理程序。我现在正在处理的选项是添加一个客户。首先，他们根据客户是批发还是零售来选择1或2。如果他们不小心输入了一个非int值，我想停止该程序。尽管我的try-catch，我仍然得到一个输入不匹配异常这里是我的代码。

 int i = 0; 


     try 
     { 
     System.out.println("Please indicate if customer is wholesale or retail. Type 1 for wholesale or 2 for retail"); 
     i = scan.nextInt(); 
     } 



     catch (InputMismatchException e) 
     { 
     System.out.println("You did not input a valid value. Please enter an Integer value between 1 and 2"); 


     } 


     while (i<1 || i>2) 
     { 
      System.out.println("You did not enter a valid value. Please enter an integer between 1 and 2"); 
      i = scan.nextInt(); 
     } 


    // The data validation previously provided was not running correctly so I changed the logic around 


     if (i == 2) 
     { 
      next.setType("Retail"); 
      System.out.println("The customer is Retail"); 
      System.out.println(""); 

     } 
     else if (i == 1) 
     { 
      next.setType("Wholesale"); 
      System.out.println("The customer is Wholesale"); 
      System.out.println(""); 

     } 

Answer 1

你应该移动的try/catch内循环：

int i = 0; 

while (i < 1 || i > 2) 
{ 
    try 
    { 
     System.out.println("Please indicate if customer is wholesale or retail. Type 1 for wholesale or 2 for retail"); 
     i = scan.nextInt(); 
    } 
    catch (InputMismatchException e) 
    { 
     System.out.println("You did not input a valid value. Please enter an Integer value between 1 and 2"); 
     scan.next(); 
    } 
} 
... 

在异常处理程序会吃他们进入任何无效的输入的scan.next()，否则你到nextInt()下一次调用将失败不管什么。