Java网络编程TCP如何实现文件上传功能

package com.kuang.lesson02;

import java.io.*;
import java.net.InetAddress;
import java.net.Socket;

//客户端
public class TcpClientDemo2 {
    public static void main(String[] args) throws Exception {
        //1、创建一个Socket连接
        Socket socket = new Socket(InetAddress.getByName("127.0.0.1"),9000);
        //2、创建一个输出流
        OutputStream os = socket.getOutputStream();
        //3、读取文件
        FileInputStream fis = new FileInputStream(new File("sendFile.jpg"));
        //4、写出文件
        byte[] buffer = new byte[1024];
        int len;
        while ((len=fis.read(buffer))!=-1) {
            os.write(buffer,0,len);
        }

        //通知服务器，我已经结束了
        socket.shutdownOutput();

        //确定服务器接收完毕，才能断开连接
        InputStream inputStream = socket.getInputStream();
        //String byte[]
        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        byte[] buffer2 = new byte[1024];
        int len2;
        while ((len2=inputStream.read(buffer2))!=-1) {
            baos.write(buffer2,0,len2);
        }

        System.out.println(baos.toString());


        //5、关闭资源
        fis.close();
        os.close();
        socket.close();
    }
}

package com.kuang.lesson02;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;

//服务端
public class TcpServerDemo02 {
    public static void main(String[] args) throws Exception {
        //1、创建服务
        ServerSocket serverSocket = new ServerSocket(9000);
        //2、监听客户端的连接
        //阻塞式监听，会一直等待客户端连接
        Socket socket = serverSocket.accept();
        //3、获取输入流
        InputStream is = socket.getInputStream();
        //4、文件输出
        FileOutputStream fos = new FileOutputStream(new File("receive.jpg"));
        byte[] buffer = new byte[1024];
        int len;
        while ((len=is.read(buffer))!=-1) {
            fos.write(buffer,0,len);
        }

        //通知客户端我接收完毕
        OutputStream os = socket.getOutputStream();
        os.write("我接收完毕了，你可以断开了".getBytes());

        //5、关闭资源
        fos.close();
        is.close();
        socket.close();
        serverSocket.close();
    }

}