從多個文件中取數據並移動到一個文件

Question

我需要一個名爲wonder1.txt的文件並將該文件中的日期寫入另一個文件。可以說我有更多的文件，如wonder2.txt,wonder3.txt,wonder4.txt。我如何在同一個文件中編寫其餘部分。

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

public class alice { 

    public static void main(String[] args) throws FileNotFoundException, IOException { 
    String fileName = ("/Users/DAndre/Desktop/Alice/wonder1.txt"); 
    BufferedReader br = new BufferedReader(new FileReader(fileName)); 
    try { 
     StringBuilder stringBuilder = new StringBuilder(); 
     String line = br.readLine(); 

     while (line != null) { 
      stringBuilder.append(line); 
      stringBuilder.append("\n"); 
      line = br.readLine(); 
     } 


     /** 
     * Pass original file content as string to another method which 
     * creates new file with same content. 
     */ 
     newFile(stringBuilder.toString()); 
    } finally { 
     br.close(); 
    } 


    } 

    public static void newFile(String fileContent) { 
    try { 
     String newFileLocation = "/Users/DAndre/Desktop/Alice/new1.txt"; 
     PrintWriter writer = new PrintWriter(newFileLocation); 
     writer.write(fileContent);//Writes original file content into new file 
     writer.close(); 
     System.out.println("File Created"); 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
    } 
} 

Answer 1

如果你有文件列表，那麼你可以循環它們一個接一個。您當前的代碼在循環內移動。 更簡單的方法是將所有文件放在一個文件夾中並從中讀取。

事情是這樣的：

File folder = new File("/Users/DAndre/Desktop/Alice"); 

    for (final File fileEntry : folder.listFiles()) { 
     String fileName = fileEntry.getAbsolutePath(); 
     BufferedReader br = new BufferedReader(new FileReader(fileName)); 
     try { 
      StringBuilder stringBuilder = new StringBuilder(); 
      String line = br.readLine(); 

      while (line != null) { 
       stringBuilder.append(line); 
       stringBuilder.append("\n"); 
       line = br.readLine(); 
      } 


      /** 
      * Pass original file content as string to another method which 
      * creates new file with same content. 
      */ 
      newFile(stringBuilder.toString()); 
     } finally { 
      br.close(); 
     } 
    }