如何在Java项目中实现一个简单的图片上传功能

import java.io.*;import java.net.*;class picsend{  public static void main(String[] args) throws Exception  {    if(args.length!=1)    {      System.out.println("请选择一张.jpg图片");      return;    }    File file = new File(args[0]);    if (!(file.exists() && file.isFile()))    {      System.out.println("图片有问题(不是文件或不存在)");      return;    }    if(!file.getName().endsWith(".jpg"))    {      System.out.println("图片格式不对，请重新选择图片");      return;    }    if(file.length()>1024*1024*10)    {      System.out.println("图片过大，无法上传");      return;    }    Socket s = new Socket("192.168.33.1",10006);//建立服务    FileInputStream fis = new FileInputStream("d:\\美女.jpg");//读取图片    OutputStream out = s.getOutputStream();//读到的写入    byte [] b = new byte[1024];    int len = 0;    while((len = fis.read(b))!= -1)    {      out.write(b,0,len);    }    s.shutdownOutput();//标记结束    InputStream in = s.getInputStream();//读服务端返回数据    byte [] bin = new byte[1024];    int num = in.read(bin);    System.out.println(new String(bin,0,num));    fis.close();    s.close();  }}class picThread implements Runnable{  private Socket s;  picThread(Socket s)  {    this.s = s;  }  public void run()  {    int count = 1;    String ip = s.getInetAddress().getHostAddress();//得到ip    try    {      System.out.println(ip+".............connect");      InputStream in = s.getInputStream();//读到流中数据      File file = new File(ip+"("+(count)+")"+".jpg");      while(file.exists())//判断文件是否存在        file = new File(ip+"("+(count++)+")"+".jpg");      FileOutputStream fos = new FileOutputStream(file);//写入      byte [] b = new byte[1024];      int len = 0;      while((len = in.read(b))!=-1)      {        fos.write(b,0,len);      }      OutputStream out = s.getOutputStream();//写入服务端传过来数据      out.write("上传成功！".getBytes());      fos.close();      s.close();    }    catch (Exception e)    {      throw new RuntimeException("上传失败");    }  }}class picrece{  public static void main(String[] args) throws Exception  {    ServerSocket ss = new ServerSocket(10006);    while(true)    {      Socket s = ss.accept();//接收      new Thread(new picThread(s)).start();    }  }}