服務端

package lesson02;

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

/**
 * 服務端接收檔案
 */
public class TcpServerDemo2 {

    public static void main(String[] args) throws IOException {
        //1、建立服務
        ServerSocket serverSocket = new ServerSocket(9000);
        //2、監聽客戶端的連線
 

        Socket socket = serverSocket.accept();//阻塞式監聽，會一直等待客戶端連線
        //3、獲取輸入流
        InputStream is = socket.getInputStream();

        //4、檔案輸出
        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);
        }

        //通知客戶端我接收完畢了
        OutputStream os = socket.getOutputStream();
        os.write("我接收完畢了，你可以斷開了".getBytes());

        //5、關閉資源
        fos.close();
        is.close();
        socket.close();
        serverSocket.close();

    }

}

客戶端

package lesson02;

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

/**
 * 客戶端上傳檔案
 */
public class TcpClientDemo2 {

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

        //1、建立一個Socket連線
        Socket socket = new Socket(InetAddress.getByName("127.0.0.1"), 90000);
        //2、建立一個輸出流
        OutputStream os = socket.getOutputStream();

        //3、讀取檔案
        FileInputStream fis = new FileInputStream(new File("toux.jpg"));
        //4、寫出檔案
        byte[] buffer = new byte[1024];
        int len;
        while ((len = fis.read(buffer)) != -1){
            os.write(buffer, 0, len);
        }

        //通知伺服器，我已經結束了
        socket.shutdownOutput(); //我已經傳輸完了

        //確定伺服器接收完畢，才能夠斷開連線
        InputStream inputStream = socket.getInputStream();
        //Sting 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、關閉資源
        fis.close();
        os.close();
        socket.close();

    }

}