java实现图片上传

/*
 *  java multiple upload demo
 *  @author:luowen
 *  @time:2013-11-06
 * */

import java.io.*;
import java.net.*;


class UploadClient
{
    public static void main(String[] args)throws Exception
    {

        if(args.length != 1)
        {
            System.out.println("输入错误,请正确输入");
            return;
        }
        
        File file = new File(args[0]);

        if(!(file.exists() && file.isFile()))
        {
            System.out.println("你输入的不是存在,或者不是文件");
            return ;
        }

        if(!file.getName().endsWith(".jpg"))
        {
            System.out.println("你输入的文件格式不正确,请输入.jpg格式的文件");
            return ;
        }

        if(file.length() >= 1024*1024*5)
        {
            System.out.println("你输入的文件过大,请输入小于5M的文件");
            return ;
        }

        Socket s = new Socket("127.0.0.1",10000);

        FileInputStream fos = new FileInputStream(file);
        OutputStream os = s.getOutputStream();

        byte[] by = new byte[1024];
        int len;

        while((len = fos.read(by)) != -1)
        {
            os.write(by,0,len);
        }

        s.shutdownOutput();

        InputStream is = s.getInputStream();

        byte[] by1 = new byte[1024];
        int num;
        while((num = is.read(by)) != -1)
        System.out.println(new String(by,0,num));

        fos.close();
        s.close();

    }
}

class UploadServer
{
    public static void main(String[] args)
    {
        try
        {
            ServerSocket ss = new ServerSocket(10000);

            while(true)
            {
                Socket s = ss.accept();
                new Thread(new UploadThread(s)).start();
            }
        
        }
        catch(Exception e)
        {
            throw new RuntimeException("监听端口失败!");
        }

    }

}

class UploadThread implements Runnable
{
    private Socket s;
    UploadThread(Socket s)
    {
        this.s = s;
    }
    public void run()
    {
        String ip = s.getInetAddress().getHostAddress();
        try
        {
            System.out.println(ip + "================connected!");
            
            int count = 0;

            File file = new File(ip+"("+count+").jpg");

            while(file.exists())
                file = new File(ip+"("+(count++)+").jpg");

            FileOutputStream fos = new FileOutputStream(file);

            InputStream is = s.getInputStream();

            byte[] by = new byte[1024];
            int len ;

            while((len = is.read(by)) != -1)
            {
                fos.write(by,0,len);
            }

            PrintWriter pw = new PrintWriter(s.getOutputStream(),true);
            pw.println(ip + "上传成功!");

            s.close();
            fos.close();
        }
        catch(Exception e)
        {
            throw new RuntimeException(ip + "上传失败!");
        }


    }
}