Java文本文件输入

Java text file input

提问by Hannah Livestrong

i am currently doing a small task in java which i am very new to so please excuse any silly mistakes i have made. Basically i am trying to take 2 values from a text document, import them into my java document and then multiply them together. These 2 numbers are meant to represent the hourly pay and amount of hours worked, then the output is the total amount the member of staff has earned. This what i have so far ...

我目前正在用 Java 做一个小任务，我对它很陌生，所以请原谅我犯的任何愚蠢的错误。基本上，我试图从文本文档中获取 2 个值，将它们导入到我的 java 文档中，然后将它们相乘。这 2 个数字代表时薪和工作时数，那么输出就是该员工的总收入。这是我到目前为止...

import java.util.*;
import java.io.*;  

public class WorkProject 
{ 

    Scanner inFile = new Scanner(new FileReader("staffnumbers.txt"));

    double Hours;
    double Pay;

    Hours = inFile.nextDouble();
    Pay = inFile.nextDouble();
    double earned = Length * Width;

            System.out.println(earned);
    }

What i have so far is basically me trying to get the .txt document into my java file. I'm not sure if this is right and then i'm not sure where to go to get the values to multiply and have it outputted. I understand what i have so far is probably just the very start of what i need but any help will be massively appreciated as i am keen to learn. Thanks so much .... Hannah

到目前为止我所拥有的基本上是我试图将 .txt 文档放入我的 java 文件中。我不确定这是否正确，然后我不确定去哪里让值相乘并输出。我知道到目前为止我所拥有的可能只是我需要的东西的开始，但由于我渴望学习，因此将非常感谢任何帮助。非常感谢......汉娜

采纳答案by jlars62

I don't know what Amount earnedis. So my guess is you need to change the last line to

我不知道什么Amount earned是。所以我的猜测是您需要将最后一行更改为

double amountEarned = Hours * Pay; //this multiplies the values
System.out.println(amountEarned);  //this outputs the value to the console

EDIT: Putting code inside a mainmethod:

编辑：将代码放入main方法中：

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

      Scanner inFile = new Scanner(new FileReader("C:\staffnumbers.txt"));

      double Hours;
      double Pay;

      Hours = inFile.nextDouble();
      Pay = inFile.nextDouble();
      double amountEarned = Hours * Pay;

      System.out.println(amountEarned);
    }
}

回答by Matt

// Matt Stillwell
// April 12th 2016
// File must be placed in root of the project folder for this example 

import java.io.File;
import java.util.Scanner;

public class Input
{

    public static void main(String[] args)
    {

        // declarations
        Scanner ifsInput;
        String sFile;

        // initializations
        ifsInput = null;
        sFile = "";

        // attempts to create scanner for file
        try
        {
            ifsInput = new Scanner(new File("document.txt"));
        }
        catch(FileNotFoundException e)
        {
            System.out.println("File Doesnt Exist");
            return;
        }

        // goes line by line and concatenates the elements of the file into a string
        while(ifsInput.hasNextLine())
            sFile = sFile + ifsInput.nextLine() + "\n";     

        // prints to console
        System.out.println(sFile);

    }
}