将指定文件夹下所有文件复制另一个文件夹中

import java.io.*;


public class DirectoryCopy{


 public static void main(String[] args)throws Exception{
  
  File f = new File("E:\\tool\\java\\j2se1.5\\docs");
  
  if(f.isDirectory()){ 
   String str = "F:\\upload\\" ;
   File d = new File(str);
   d.mkdir();
   copy(f,str);

  }
  

 }
 public static void copy(File f,String str)throws Exception{
  File[] fs = f.listFiles(); 
  FileInputStream in ;
  FileOutputStream out;
  for(int i=0 ; i<fs.length; i++){
   if(fs[i].isDirectory()) { 
    File file = new File(str+fs[i].getName());
    file.mkdir();
    copy(fs[i],str+fs[i].getName()+"\\");
   }
   in = new FileInputStream(fs[i]);
   out= new FileOutputStream(str+fs[i].getName());
   byte[] context = new byte[1024] ;
   int length;
   while((length=in.read(context))!=-1){
    out.write(context,0,length);
    out.flush();
   } 
   out.close();  
   in.close(); 
  }
 }

}