缓存字节流-写coppy方法

package ba;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import java.util.*;

public class huancunTest {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		Date d1=new Date();
		Date d2=new Date();
		long l1=d1.getTime();
		copy("G:/a.png","G:/test/a.png");
		long l2=d2.getTime();
		System.out.println(l2-l1);

	}
	public static void copy(String str,String des){
		File srcFile = new File(str);
		File desFile = new File(des);
		BufferedInputStream bis = null;
		BufferedOutputStream bos = null;

		try {
			bis = new BufferedInputStream(new FileInputStream(srcFile));
			bos = new BufferedOutputStream(new FileOutputStream(desFile));

			byte[]b=new byte[1024];
			int len=0;
			try {
				while((len=bis.read(b))>0){
					bos.write(b,0,len);
				}
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}

		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}finally{
			if(bis!=null){
				try {
					bis.close();
					bos.close();
				} catch (IOException e) {
					// TODO Auto-generated catch block
					e.printStackTrace();
				}
			}
		}

	}

}