java复制文件

package com.test.tes;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.util.Date;

/**
 * 复制文件到指定目录下
 * @author Wdnncey
 *
 */

public class Copy {

     public static long forJava(File f1,File f2) throws Exception{
          long time=new Date().getTime();
          int length=2097152;
          FileInputStream in=new FileInputStream(f1);
          FileOutputStream out=new FileOutputStream(f2);
          byte[] buffer=new byte[length];
          while(true){
           int ins=in.read(buffer);
           if(ins==-1){
            in.close();
            out.flush();
            out.close();
            return new Date().getTime()-time;
           }else
            out.write(buffer,0,ins);
          }
         }

    public static void main(String[] args) {
        try {
            forJava(new File("1.zip"), new File("e:\\a\\b\\2.zip"));
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

}