//TCP客戶端
public class TCPClient {

    public static void main(String[] args)throws IOException {
        Socket socket = new Socket("127.0.0.1",8888);
        OutputStream out = socket.getOutputStream();
        FileInputStream fis = new FileInputStream("d:\\jay.jpg");
        byte[] data = new byte
 
[1024];
        int len = 0;
        while((len = fis.read(data)) != -1){
            out.write(data,0,len);
        }
        
        //給伺服器寫終止序列
        socket.shutdownOutput();
        
        //得到的迴應
        InputStream in = socket.getInputStream();
        len = in.read(data);
        System.out.println(
 
new String(data,0,len));
        
        //關閉資源
        fis.close();
        socket.close();
    }

}

TCP服務端：

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Random;

 
public class TCPServer {

    public static void main(String[] args) throws IOException{
        ServerSocket server = new ServerSocket(8888);
        Socket socket = server.accept();
        //處理客戶端傳來的檔案流
        InputStream in = socket.getInputStream();
        File upload = new File("d:\\upload");
        if(!upload.exists()){
            upload.mkdir();
        }
        String filename = "taobao" + System.currentTimeMillis() + new Random().nextInt(999999) +".jpg";
        FileOutputStream fos = new FileOutputStream(upload+File.separator+filename);
        int len = 0;
        byte[] data = new byte[1024];
        while((len = in.read(data)) != -1){
            fos.write(data,0,len);
        }

        //回覆客戶端
        socket.getOutputStream().write("上傳成功！".getBytes());
        
        //關閉流資源
        fos.close();
        socket.close();
        server.close();
    }

}

 進階：（多執行緒圖片上傳服務）

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

public class TCPThreadServer {

    public static void main(String[] args) throws IOException{
        ServerSocket server = new ServerSocket(8888);
        while(true){
            //獲取到一個客戶端，必須開啟新執行緒
            Socket socket = server.accept();
            new Thread(new Upload(socket)).start();            
        }
    }

}

TCP服務端程式碼封裝到 run 方法中

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Random;

public class Upload implements Runnable{
    private static Socket socket;
    
    public Upload(Socket socket){
        this.socket = socket;
    }
    
    public void run(){
        try{
            //處理客戶端傳來的檔案流
            InputStream in = socket.getInputStream();
            File upload = new File("d:\\upload");
            if(!upload.exists()){
                upload.mkdir();
            }
            String filename = "itcast" + System.currentTimeMillis() + new Random().nextInt(999999) +".jpg";
            FileOutputStream fos = new FileOutputStream(upload+File.separator+filename);
            int len = 0;
            byte[] data = new byte[1024];
            while((len = in.read(data)) != -1){
                fos.write(data,0,len);
            }

            //回覆客戶端
            socket.getOutputStream().write("上傳成功！".getBytes());
            
            //關閉流資源
            fos.close();
            socket.close();
        }catch(Exception ex){}
        
    }
}