如何將我的文件從一個目錄複製到另一個目錄？

Question

我正在使用Android。我的要求是我有一個目錄有一些文件，後來我下載了一些其他文件到另一個目錄，我的意圖是將最新目錄中的所有文件複製到第一個目錄中。在將文件從最新複製到第一個目錄之前，我需要從第一個目錄中刪除所有文件。

Answer 1

void copyFile(File src, File dst) throws IOException { 
     FileChannel inChannel = new FileInputStream(src).getChannel(); 
     FileChannel outChannel = new FileOutputStream(dst).getChannel(); 
     try { 
      inChannel.transferTo(0, inChannel.size(), outChannel); 
     } finally { 
      if (inChannel != null) 
      inChannel.close(); 
      if (outChannel != null) 
      outChannel.close(); 
     } 
    } 

我不記得我在哪裏找到了這個，但它來自於我用來備份SQLite數據庫的有用文章。

Answer 2

你也必須使用下面的代碼：

public static void copyDirectoryOneLocationToAnotherLocation(File sourceLocation, File targetLocation) 
     throws IOException { 

    if (sourceLocation.isDirectory()) { 
     if (!targetLocation.exists()) { 
      targetLocation.mkdir(); 
     } 

     String[] children = sourceLocation.list(); 
     for (int i = 0; i < sourceLocation.listFiles().length; i++) { 

      copyDirectoryOneLocationToAnotherLocation(new File(sourceLocation, children[i]), 
        new File(targetLocation, children[i])); 
     } 
    } else { 

     InputStream in = new FileInputStream(sourceLocation); 

     OutputStream out = new FileOutputStream(targetLocation); 

     // Copy the bits from instream to outstream 
     byte[] buf = new byte[1024]; 
     int len; 
     while ((len = in.read(buf)) > 0) { 
      out.write(buf, 0, len); 
     } 
     in.close(); 
     out.close(); 
    } 

} 

Answer 3

阿帕奇fileutils中做到這一點很簡單，很好..

包括阿帕奇公地IO包添加公地io.jar

或

commons-io android gradle dependancy

compile 'commons-io:commons-io:2.4' 

添加該代碼

String sourcePath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/TongueTwister/sourceFile.3gp"; 
     File source = new File(sourcePath); 

     String destinationPath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/TongueTwister/destFile.3gp"; 
     File destination = new File(destinationPath); 
     try 
     { 
      FileUtils.copyFile(source, destination); 
     } 
     catch (IOException e) 
     { 
      e.printStackTrace(); 
     }