將使用BufferedReader讀取的數字相加

Question

我試圖在我的scores.txt文件中獲得20個數字的均值，但我無法弄清楚如何去做。每次我嘗試，我的輸出都搞砸了。思考？

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

    String file ="/Users/vienna01pd2016/Desktop/scores/src/scores/scores.txt"; 
    processFile("/Users/vienna01pd2016/Desktop/scores/src/scores/scores.txt"); 
    //calls method processFile 
    } 


    public static void processFile (String file) 
    throws IOException, FileNotFoundException{ 
    String line; 
    //lines is declared as a string 


    BufferedReader inputReader = 
     new BufferedReader (new InputStreamReader 
(new FileInputStream(file))); 

    while ((line = inputReader.readLine()) != null){ 

     //System.out.println(line); 
     double Value = Double.parseDouble(line); 
    System.out.println(Value); 

Answer 1

如果你有每行一個號碼，我會閱讀使用BufferedReader中的每一行，把它放在一個列表，以及將它添加到一個號碼，那麼你可以通過數字量除以全部在列表中：

package Testers; 

import java.io.BufferedReader; 
import java.io.File; 
import java.io.IOException; 
import java.io.FileReader; 
import java.util.ArrayList; 

public class MeanGetter { 

    public static ArrayList<Double> ls = new ArrayList<Double>(); 

    public static void main(String[] args){ 
     String filepath = "/Users/vienna01pd2016/Desktop/scores/src/scores/scores.txt"; 
     double total = processFile(/*new File(filepath).getAbsolutePath()*/ filepath); 
     double mean = total/ls.size(); 
     System.out.println("mean: " + mean); 
    } 

    private static double processFile(String path) { 
     double n = 0; 
     try { 
      BufferedReader reader = new BufferedReader(new FileReader(new File(path))); 
      String line; 
      while ((line = reader.readLine()) != null){ 
       double d = Double.parseDouble(line); 
       n = n + d; 
       ls.add(d); 
      } 
      reader.close(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
     return 0; 


    } 

}