扫描器，nextInt和InputMismatchException [英] Scanner, nextInt and InputMismatchException

问题描述

我试图读取一个文本文件，然后使用Java中的nextInt（）函数在循环中打印出整数。我的文本文件格式为：

$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $
d 5000 6

这里是我的代码：

  public static void main（String [] args）throws FileNotFoundException {
 
 String fileSpecified = args [0] +.txt; 
 
 FileReader fr = new FileReader（fileSpecified）; 
 BufferedReader br = new BufferedReader（fr）; 
扫描仪输入=新扫描仪（br）; （in.hasNextLine（））{
 System.out.println（next int =+ in.nextInt（））; 
 
 while（in.hasNextLine 
 
 
 $ / code $ / pre 
 $ b $我得到的错误是：
 
 
 pre $ 异常在线程mainjava.util.InputMismatchException $ b $在java.util.Scanner.throwFor（未知源）
在java.util.Scanner.next（未知源）$ b $在java.util.Scanner.nextInt（未知源）$ b $在java.util.Scanner.nextInt（未知源）
  

每当我在任何程序中使用nextInt（）时，都会得到这个错误。


  while（in.hasNext）
 （））{
 System.out.println（letter =+ in.next（））; 
 System.out.println（integer1 =+ in.nextInt（））; 
 System.out.println（integer2 =+ in.nextInt（））; 
} 
  

I'm trying to read a text file and then print out the integers in a loop using the nextInt() function in Java. The text file I have is of the form:

a 2000 2
b 3000 1
c 4000 5
d 5000 6

Here is my code:

public static void main(String[] args) throws FileNotFoundException {

  String fileSpecified = args[0] + ".txt";

  FileReader fr = new FileReader(fileSpecified);
  BufferedReader br = new BufferedReader (fr);
  Scanner in = new Scanner (br);

  while (in.hasNextLine()) {
    System.out.println ("next int = " + in.nextInt());
  }
}

The error I always get is:

Exception in thread "main" java.util.InputMismatchException
           at java.util.Scanner.throwFor(Unknown Source)
           at java.util.Scanner.next(Unknown Source)
           at java.util.Scanner.nextInt(Unknown Source)
           at java.util.Scanner.nextInt(Unknown Source)

I get this error everytime I use nextInt() in any program.

解决方案

You probably want something like this instead:

while (in.hasNext()) {
    System.out.println("letter = " + in.next());
    System.out.println("integer1 = " + in.nextInt());
    System.out.println("integer2 = " + in.nextInt());
}

这篇关于扫描器，nextInt和InputMismatchException的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！