java将一个目录下的所有数据复制到另一个目录下

/*
  将"C:\\JavaProducts\\Source"下的所有数据复制到"C:\\Target"下
*/

import java.io.*;

public class JavaCopyDemo{
  final static String SOURCESTRING = "C:\\JavaProducts\\Source";
  final static String TARGETSTRING = "C:\\Target";
  
  public static void main(String[] args){
    if(!(new File(SOURCESTRING)).exists()){
      System.out.println("源文件" + SOURCESTRING + "不存在，无法复制！");
      return;
    }else if((new File(TARGETSTRING)).exists()){
      System.out.println("目标文件" + TARGETSTRING + "已经存在，无法复制！");
      return;
    }else{
      if((new File(SOURCESTRING)).isFile()){
        copyFile(new File(SOURCESTRING),new File(TARGETSTRING));
      }else if((new File(SOURCESTRING)).isDirectory()){
        copyDirectory(SOURCESTRING,TARGETSTRING);
      }
    }
  }
  
  private static void copyFile(File sourceFile,File targetFile){
    if(!sourceFile.canRead()){
      System.out.println("源文件" + sourceFile.getAbsolutePath() + "不可读，无法复制！");
      return;
    }else{
      System.out.println("开始复制文件" + sourceFile.getAbsolutePath() + "到" + targetFile.getAbsolutePath());
      FileInputStream fis = null;
      BufferedInputStream bis = null;
      FileOutputStream fos = null;
      BufferedOutputStream bos = null;
      
      try{
        fis = new FileInputStream(sourceFile);
        bis = new BufferedInputStream(fis);
        fos = new FileOutputStream(targetFile);
        bos = new BufferedOutputStream(fos);
        int len = 0;
        while((len = bis.read()) != -1){
          bos.write(len);  
        }
        bos.flush();
        
      }catch(FileNotFoundException e){
        e.printStackTrace();  
      }catch(IOException e){
        e.printStackTrace();
      }finally{
        try{
          if(fis != null){
            fis.close();  
          }
          if(bis != null){
            bis.close();  
          }
          if(fos != null){
            fos.close();  
          }
          if(bos != null){
            bos.close();  
          }
          System.out.println("文件" + sourceFile.getAbsolutePath() + "复制到" + targetFile.getAbsolutePath() + "完成");
        }catch(IOException e){
          e.printStackTrace();
        }
      }
    }
  }
  
  private static void copyDirectory(String sourcePathString,String targetPathString){
    if(!new File(sourcePathString).canRead()){
      System.out.println("源文件夹" + sourcePathString + "不可读，无法复制！");
      return;
    }else{
      (new File(targetPathString)).mkdirs();
      System.out.println("开始复制文件夹" + sourcePathString + "到" + targetPathString);
      File[] files = new File(sourcePathString).listFiles();
      for(int i = 0; i < files.length; i++){
        if(files[i].isFile()){
          copyFile(new File(sourcePathString + File.separator + files[i].getName()),new File(targetPathString + File.separator + files[i].getName()));  
        }else if(files[i].isDirectory()){
          copyDirectory(sourcePathString + File.separator + files[i].getName(),targetPathString + File.separator + files[i].getName());
        }  
      }
      System.out.println("复制文件夹" + sourcePathString + "到" + targetPathString + "结束");
    }
  }
}