Java文件输入和从数据到文件输出的操作

嘿，那么aim正在开发一个程序，该程序从一个文本文件中读取运动数据，并将该数据的摘要打印到另一个文本文件中。输入文件由多条记录组成 txt文件中的示例输入如下所示：

   1) Joe Schmoe
   76.5 20 30 25 10 75.9
   Jilly Momilly Schmill
   50.5 30 30 35 37 28 32 35 34 34 49.2
   Gail Quail
   62.3 15 17 10 3 10 63.6
   Frank Crank
   83.2 5 83.2
   John Quann
   57.9 30 32 35 32 30 57.2       

我的问题是我不能让我的代码读取每个人，我只能让它读取第一个，或者让我进入无限循环或输入不匹配。 这是我的密码：

`//Doubler.java
import java.util.Scanner;
import java.io.File;
import java.io.FileNotFoundException;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.BufferedWriter;
import java.io.BufferedReader;
import java.io.FileOutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.io.PrintWriter;
import java.util.Scanner;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.FileNotFoundException;
import java.io.EOFException;
import java.io.IOException;

public class ExerciseSummary
{
    private Scanner inputStream = null;
    private PrintWriter outputStream = null;
    private int next = 0;
    private int sum = 0;
    private int count = 0;
    private double avg = 0;
    private double firstWeight = 0;
    private double lastWeight = 0;
    private String line;

    public static void main(String[] args)
        {
        ExerciseSummary summary = new ExerciseSummary();
        summary.connectToInputFile();
        summary.connectToOutputFile();
        summary.summaryData();
        summary.closeFiles();
        System.out.println("\nAll numbers from the input file have been");
        System.out.println("summarized and copied to the output file.");
    }

    public void connectToInputFile()
    {
        String inputFileName = getFileName("\nEnter name of input file: ");
        try
        {
            inputStream =
                new Scanner(new File(inputFileName));
        }
        catch(FileNotFoundException e)
        {
            System.out.println("File " + inputFileName + " not found.");
            System.exit(0);
        }
        catch(IOException e)
        {
            System.out.println("Error opening input file " + inputFileName);
            System.exit(0);
        }
    }

    private String getFileName(String prompt)
    {
        String fileName = null;
        System.out.print(prompt);
        Scanner keyboard = new Scanner(System.in);
        fileName = keyboard.next();
        return fileName; 
    }

    public void connectToOutputFile()
    {
        String outputFileName = getFileName("Enter name of output file: ");
        try
        {
            //outputStream = new PrintWriter(outFile);
            outputStream =
                new PrintWriter(outputFileName);
        }
        catch(IOException e)
        {
            System.out.println("Error opening output file " + outputFileName);
            //System.out.println(e.getMessage());
            System.exit(0);
        }
    }

    public void summaryData()
    {
        try 
        {
            while (inputStream.hasNext());
            {
                line = inputStream.nextLine();
                firstWeight = inputStream.nextDouble();
                while (inputStream.hasNextInt()) 
                {
                            sum += inputStream.nextInt();
                    count ++;
                    avg = (sum/count);
                    }
                lastWeight = inputStream.nextDouble();
                        outputStream.println(line + " " + firstWeight + " " + sum + " " +  count + " " +  lastWeight + " " + avg + " " + (lastWeight-firstWeight));
            }
        }
        catch (InputMismatchException e) 
        {
            System.out.print(e);
            System.exit(0);
        }
    }

    public void closeFiles()
    {
            inputStream.close();
            outputStream.close();
    }
}       

输出记录是输入记录的摘要。它由四个选项卡分隔的值组成：该参与者的数据天数、锻炼的总分钟数、每天锻炼的平均分钟数，以及如果参与者体重增加将为负数的总体重减轻量。该名称已被读入，但未再次打印出来。我们正在对数据进行匿名处理。根据上述记录，受试者的名字是乔·施莫，他的起始体重是76.5公斤。Joe锻炼了四天，在开始体重和最终体重之间有四个int值，总共85分钟20+30+25+10=85。他的最终体重是75.9公斤。输出记录为： 4 85 21.25 0.59999999943

我绞尽脑汁已经两个星期了，如果有任何帮助，我将不胜感激。谢谢你

无限循环：

while (inputStream.hasNext());
        {
            line = inputStream.nextLine();
            firstWeight = inputStream.nextDouble();
            while (inputStream.hasNextInt()) 
            {
                        sum += inputStream.nextInt();
                count ++;
                avg = (sum/count);
                }
            lastWeight = inputStream.nextDouble();
                    outputStream.println(line + " " + firstWeight + " " + sum + " " + count + " " +  lastWeight + " " + avg + " " + (lastWeight-firstWeight));
        }

)；while inputStream.hasNext是一个空表达式，因此java只需执行；而inputStream.hasNext和不使用该文件

下一个问题是InputMissmatchException： 扫描仪需要这行代码：

inputStream =
            new Scanner(new File("C:\\Test\\readTest.txt"));
inputStream.useLocale(Locale.ENGLISH);//this will help to interpret "." as decimal character

最后一个问题是，在while结束时需要这两行代码来使用换行符：

lastWeight = inputStream.nextDouble();
                    outputStream.println(line + " " + firstWeight + " " + sum + " " +  count + " " +  lastWeight + " " + avg + " " + (lastWeight-firstWeight));
if(inputStream.hasNext())
    inputStream.next(); // or even inputStream.nextLine();

现在我为第一人称： Joe Schmoe 76.5 85 4 75.9 21.0-0.599999943

---

结果是否正确？

无限循环或输入不匹配发生在哪里？在它询问输出文件的名称后，它进入无限循环。请将您的预期输出发布给第一人称。不匹配也发生在那里。当我使用hasNext或hasNext时，似乎有所不同；或拥有nextLine；这是期望的输出：4 85 21.25 0.599999999943谢谢，我甚至没有注意到现在它给了我java.util。InputMismatchException@user3389626如果输出正确，我认为这应该有效。对不起，我如何使用inputStream.useLocaleScale.ENGLISH；我需要进口什么东西吗？找不到符号：变量Localeimport java.util.Locale；工作正常吗？输出结果如何？这不是你想要的1:1输出，对吗？