线程"main" java.lang.NumberFormat异常：对于输入字符串："3 50"

Question

我的代码使用Netbeans IDE。当我尝试运行它时，我得到了这个错误：

Exception in thread "main" java.lang.NumberFormatException: For input string: "3    50"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    at java.lang.Integer.parseInt(Integer.java:492)
    at java.lang.Integer.parseInt(Integer.java:527)
    at spacely.sprockets.broc.east.SpacelySprocketsBrocEast.main(SpacelySprocketsBrocEast.java:32)

我还没能在程序中找出会导致这种情况的错误。我的代码在下面。如果有人能为我指明正确的方向，我将不胜感激。谢谢

 package spacely.sprockets.broc.east;
 import java.io.BufferedReader;
 import java.io.FileReader;
 import java.io.File;
 import java.io.FileWriter;
 import java.io.BufferedWriter;
 import java.io.IOException;
 public class SpacelySprocketsBrocEast
 {

     public static void main(String[] args)
     {
         BufferedReader br = null;
         BufferedWriter bw = null;
        try
        {
            br = new BufferedReader(new FileReader("sprocketorders.txt"));
            String line;
            String element[] = new String[2];
            int   sum[] = new int[5];
            File file = new File ("sprocketorders.txt");
            while ((line = br.readLine()) != null)
            {
                element = line.split(" ");
                switch(Integer.parseInt(element[0]))
                {
                    case 1:
                        sum[0] = sum[0] + Integer.parseInt(element[1]);
                        break;
                    case 2:
                        sum[1] = sum[1] + Integer.parseInt(element[1]);
                        break;
                    case 3:
                        sum[2] = sum[2] + Integer.parseInt(element[1]);
                        break;
                    case 4:
                        sum[3] = sum[3] + Integer.parseInt(element[1]);
                        break;
                    case 5:
                        sum[4] = sum[4] + Integer.parseInt(element[1]);
                        break;
                }
            }
            if (!file.exists())
            {
                file.createNewFile();
            }
            FileWriter fw = new FileWriter(file.getAbsoluteFile());
            bw = new BufferedWriter(fw);
            bw.write("Spacely SprocketsnTaking Sprockets into the FuturenSales Summary ReportnSprocket Number Total Quantity Soldn");
            for(int i = 0; i < sum.length; i++)
                bw.write((i + 1) + "t" + sum[i] + "n");
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        finally
        {
            try
            {
                if (br != null)
                    br.close();
                if (bw != null)
                    bw.close();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
        }
     }
 }

Answer 1

错误消息似乎相当明确。Java不知道如何将3 50解释为单个整数。

如果您想知道原因，请使用调试器或将print语句放在该行之前。抛出异常之前的最后几张照片应该很有启发性。