文件副本卡在无限循环中

下面的代码似乎卡在无限循环中。我必须终止程序来停止它的运行。文件副本卡在无限循环中

下面是输出&代码 -

File copied from c:\projects\test\buildlist.txt to c:\projects\test\newtest\buildlist.txt 
File copied from c:\projects\test\GHTELE5S605A.jad to c:\projects\test\newtest\GHTELE5S605A.jad 
File copied from c:\projects\test\GHTELE5S605A.jar to c:\projects\test\newtest\GHTELE5S605A.jar 
File copied from c:\projects\test\GHTele5T240w400h.jad to c:\projects\test\newtest\GHTele5T240w400h.jad 
File copied from c:\projects\test\GHTele5T240w400h.jar to c:\projects\test\newtest\GHTele5T240w400h.jar 
File copied from c:\projects\test\newtest\buildlist.txt to c:\projects\test\newtest\newtest\buildlist.txt 
File copied from c:\projects\test\newtest\GHTELE5S605A.jad to c:\projects\test\newtest\newtest\GHTELE5S605A.jad 
File copied from c:\projects\test\newtest\GHTELE5S605A.jar to c:\projects\test\newtest\newtest\GHTELE5S605A.jar 
File copied from c:\projects\test\newtest\GHTele5T240w400h.jad to c:\projects\test\newtest\newtest\GHTele5T240w400h.jad 
File copied from c:\projects\test\newtest\GHTele5T240w400h.jar to c:\projects\test\newtest\newtest\GHTele5T240w400h.jar 
File copied from c:\projects\test\newtest\newtest\buildlist.txt to c:\projects\test\newtest\newtest\newtest\buildlist.txt 
File copied from c:\projects\test\newtest\newtest\GHTELE5S605A.jad to c:\projects\test\newtest\newtest\newtest\GHTELE5S605A.jad 
File copied from c:\projects\test\newtest\newtest\GHTELE5S605A.jar to c:\projects\test\newtest\newtest\newtest\GHTELE5S605A.jar 
File copied from c:\projects\test\newtest\newtest\GHTele5T240w400h.jad to c:\projects\test\newtest\newtest\newtest\GHTele5T240w400h.jad 
File copied from c:\projects\test\newtest\newtest\GHTele5T240w400h.jar to c:\projects\test\newtest\newtest\newtest\GHTele5T240w400h.jar 
File copied from c:\projects\test\newtest\newtest\newtest\buildlist.txt to c:\projects\test\newtest\newtest\newtest\newtest\buildlist.txt 
File copied from c:\projects\test\newtest\newtest\newtest\GHTELE5S605A.jad to c:\projects\test\newtest\newtest\newtest\newtest\GHTELE5S605A.jad 
File copied from c:\projects\test\newtest\newtest\newtest\GHTELE5S605A.jar to c:\projects\test\newtest\newtest\newtest\newtest\GHTELE5S605A.jar 
File copied from c:\projects\test\newtest\newtest\newtest\GHTele5T240w400h.jad to c:\projects\test\newtest\newtest\newtest\newtest\GHTele5T240w400h.jad 
File copied from c:\projects\test\newtest\newtest\newtest\GHTele5T240w400h.jar to c:\projects\test\newtest\newtest\newtest\newtest\GHTele5T240w400h.jar 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\buildlist.txt to c:\projects\test\newtest\newtest\newtest\newtest\newtest\buildlist.txt 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\GHTELE5S605A.jad to c:\projects\test\newtest\newtest\newtest\newtest\newtest\GHTELE5S605A.jad 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\GHTELE5S605A.jar to c:\projects\test\newtest\newtest\newtest\newtest\newtest\GHTELE5S605A.jar 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\GHTele5T240w400h.jad to c:\projects\test\newtest\newtest\newtest\newtest\newtest\GHTele5T240w400h.jad 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\GHTele5T240w400h.jar to c:\projects\test\newtest\newtest\newtest\newtest\newtest\GHTele5T240w400h.jar 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\newtest\buildlist.txt to c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\buildlist.txt 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\newtest\GHTELE5S605A.jad to c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\GHTELE5S605A.jad 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\newtest\GHTELE5S605A.jar to c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\GHTELE5S605A.jar 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\newtest\GHTele5T240w400h.jad to c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\GHTele5T240w400h.jad 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\newtest\GHTele5T240w400h.jar to c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\GHTele5T240w400h.jar 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\buildlist.txt to c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\newtest\buildlist.txt 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\GHTELE5S605A.jad to c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\newtest\GHTELE5S605A.jad 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\GHTELE5S605A.jar to c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\newtest\GHTELE5S605A.jar 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\GHTele5T240w400h.jad to c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\newtest\GHTele5T240w400h.jad 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\GHTele5T240w400h.jar to c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\newtest\GHTele5T240w400h.jar 
File copied from c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\newtest\buildlist.txt to c:\projects\test\newtest\newtest\newtest\newtest\newtest\newtest\newtest\newtest\buildlist.txt

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

    args = new String[2]; 
    args[0] = "c:\\projects\\test"; 
    args[1] = "c:\\projects\\test\\newtest"; 

     File srcFolder = new File(args[0]); 
     File destFolder = new File(args[1]); 

     //make sure source exists 
     if(!srcFolder.exists()){ 

      System.out.println("Directory does not exist."); 
      //just exit 
      System.exit(0); 

     }else{ 

      try{ 
      copyFolder(srcFolder,destFolder); 
      }catch(IOException e){ 
      e.printStackTrace(); 
      //error, just exit 
       System.exit(0); 
      } 
     } 

     System.out.println("Done"); 
    } 

    public static void copyFolder(File src, File dest) 
     throws IOException{ 

     if(src.isDirectory()){ 

      //if directory not exists, create it 
      if(!dest.exists()){ 
       dest.mkdir(); 
       System.out.println("Directory copied from " 
           + src + " to " + dest); 
      } 

      //list all the directory contents 
      String files[] = src.list(); 

      for (String file : files) { 
       //construct the src and dest file structure 
       File srcFile = new File(src, file); 
       File destFile = new File(dest, file); 
       //recursive copy 
       copyFolder(srcFile,destFile); 
      } 

     }else{ 
      //if file, then copy it 
      //Use bytes stream to support all file types 
      InputStream in = new FileInputStream(src); 
       OutputStream out = new FileOutputStream(dest); 

       byte[] buffer = new byte[1024]; 

       int length; 
       //copy the file content in bytes 
       while ((length = in.read(buffer)) > 0){ 
        out.write(buffer, 0, length); 
       } 

       in.close(); 
       out.close(); 
       System.out.println("File copied from " + src + " to " + dest); 
     } 
    } 
}

感谢您的帮助。

来源

2010-12-17 blue-sky

您应该学习如何使用调试器，这样您就可以在任何人回答您的发布之前就发现错误。 – perdian 2010-12-17 13:16:01

在循环列出的文件时过滤掉目标目录。

if (src.equals(destFolder)) { 
    continue; 
}

我建议你使用File[] files = src.listFiles();而不是src.list()。

并且注意将数组括号放在类型而不是变量上是更好的样式，即File[] files而不是File files[]。

另请注意：读取文件时发现错误。 InputStream.read(byte[])即使未到达文件结尾也可能返回0，请检查!= -1而不是> 0。

来源

2010-12-17 13:25:00

try{ 
    copyFolder(srcFolder,destFolder);  // <-- this is where your problem lies 
}catch(IOException e){

你的程序进入无限递归，因为在这个方法中，你再次为新创建的目录调用它。

您应该重写它，以便它只递归遍历源目录。

来源

2010-12-17 13:17:43 darioo

问题出在您将文件复制到源目录的子目录的事实。

当列出的文件和目录进行复制，你应该排除的目标目录，否则就必然会陷入一个死循环：

String files[] = src.list(); 
for (String file : files) { 
    // Test if the file is equal to the destination directory; 
    // - if so, just skip it ! (continue) 
    // - if not so, you can process the file 
}

来源

2010-12-17 13:29:55

感谢您的帮助 – 2010-12-17 14:39:30

如果你不需要写复制功能你自己，你应该用图书馆来做到这一点。像Apache commons IO一样。

否则检查您是否未将目标（作为源）复制到目标。

来源

2010-12-17 16:26:37 SPee

文件副本卡在无限循环中

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