请写出简单的java socket通信代码

当然可以，以下是一个简单的 Java Socket 通信代码示例：

Server 端代码：

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

public class Server {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = new ServerSocket(8888);
        System.out.println("Server started, waiting for client...");

        Socket clientSocket = serverSocket.accept();
        System.out.println("Client connected: " + clientSocket.getInetAddress().getHostAddress());

        BufferedReader in = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
        PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);

        String inputLine;
        while ((inputLine = in.readLine()) != null) {
            System.out.println("Client: " + inputLine);
            out.println("Server: " + inputLine);
        }

        in.close();
        out.close();
        clientSocket.close();
        serverSocket.close();
    }
}

Client 端代码：

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

public class Client {
    public static void main(String[] args) throws IOException {
        Socket socket = new Socket("localhost", 8888);
        System.out.println("Connected to server: " + socket.getInetAddress().getHostAddress());

        BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
        PrintWriter out = new PrintWriter(socket.getOutputStream(), true);

        BufferedReader stdIn = new BufferedReader(new InputStreamReader(System.in));
        String userInput;
        while ((userInput = stdIn.readLine()) != null) {
            out.println(userInput);
            System.out.println("Server: " + in.readLine());
        }

        in.close();
        out.close();
        stdIn.close();
        socket.close();
    }
}

这个示例中，Server 端监听 8888 端口，等待客户端连接。客户端连接后，Server 端通过 BufferedReader 和 PrintWriter 分别获取输入流和输出流，然后通过 while 循环不断读取客户端发送的消息，并将消息原样返回给客户端。

Client 端连接到 Server 端的 8888 端口，同样通过 BufferedReader 和 PrintWriter 分别获取输入流和输出流，然后通过 while 循环不断读取用户输入的消息，并将消息发送给 Server 端，然后等待 Server 端返回的消息并打印出来。

这样就实现了一个简单的 Java Socket 通信。