java 四种方式实现字符流文件的拷贝对比

package Copy;

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

/*
 * 文件复制方式，字节流，一个4个方式
 * 1.字节流读写单个字节
 * 2.字节流读写字节数组
 * 3.字节缓冲区读写单个字节
 * 4.字节缓冲区读写字节数组
 */
public class Copy {
    public static void main(String[] args) throws IOException {
        long s=System.currentTimeMillis();
        copy_4(new File("E:\\应用软件\\vm.exe"),new File("c:\\vm.exe"));
        long e=System.currentTimeMillis();
        System.out.println(e-s);
    }
    /*
     * 方法：实现文件复制
     *     4.字节流缓冲区流读写字节数组
     */
    public static void copy_4(File src,File desc)throws IOException{
        BufferedInputStream bis=new BufferedInputStream(new FileInputStream(src));
        BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(desc));
        int len=0;
        byte[] bytes=new byte[1024];
        while((len=bis.read(bytes))!=-1){
            bos.write(bytes,0,len);
        }
        bos.close();
        bis.close();
    }
    /*
     *    方法：实现文件复制    
     *     3，字节流缓冲区流读写单个字节
     */
    public static void copy_3(File src,File desc)throws IOException{
        BufferedInputStream bis=new BufferedInputStream(new FileInputStream(src));
        BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(desc));
        int len=0;
        while((len=bis.read())!=-1){
            bos.write(len);
        }
        bos.close();
        bis.close();
    }
    
    /*
     * 方法:实现复制
     *     2.字节流读写字节数组
     */
    public static void copy_2(File src,File desc)throws IOException{
        FileInputStream fis=new FileInputStream(src);
        FileOutputStream fos=new FileOutputStream(desc);
        int len=0;
        byte[] bytes=new byte[1024];
        while((len=fis.read(bytes))!=-1){
            fos.write(bytes,0,len);            
        }
        fos.close();
        fis.close();
    }

    /*
     * 方法：实现文件复制
     * 1.字节流读写单个字节
     */
    public static void copy_1(File src,File desc) throws IOException{
        FileInputStream fis=new FileInputStream(src);
        FileOutputStream fos=new FileOutputStream(desc);
        int len=0;
        while((len=fis.read())!=-1){
            fos.write( len);
            
        }
        fos.close();
        fis.close();
    }

}