java网络通信技术之简单聊天小程序

这里是关于“Java网络通信技术之简单聊天小程序”的完整攻略。

简介

本篇攻略将为大家介绍如何使用Java网络通信技术开发简单聊天小程序。

聊天小程序主要由客户端和服务端两个部分组成，它们之间通过网络通信进行交互。在Java中，可以使用Socket实现网络通信。

下面我们将由客户端和服务端两个方面详细讲解。

客户端

客户端主要负责向服务端发送信息，并接收服务端的返回信息。

首先，客户端需要创建一个Socket对象，指定服务器IP地址和端口号：

Socket socket = new Socket("127.0.0.1", 8888);

通过这个Socket对象，我们就可以向服务器发送信息：

OutputStream os = socket.getOutputStream();
String message = "Hello Server!";
os.write(message.getBytes());

同样，客户端也可以通过Socket对象接收服务端返回的信息：

InputStream is = socket.getInputStream();
byte[] buffer = new byte[1024];
int length = is.read(buffer);
String message = new String(buffer, 0, length);
System.out.println("Received message: " + message);

服务端

服务端主要负责接收客户端发送来的信息，并向客户端返回信息。

服务端需要创建一个ServerSocket对象，并指定端口号：

ServerSocket serverSocket = new ServerSocket(8888);

服务端可以通过ServerSocket对象接收客户端的连接请求：

Socket socket = serverSocket.accept();

一旦服务端接收到客户端的连接请求，就可以通过Socket对象接收客户端发送过来的信息：

InputStream is = socket.getInputStream();
byte[] buffer = new byte[1024];
int length = is.read(buffer);
String message = new String(buffer, 0, length);
System.out.println("Received message: " + message);

服务端也可以通过Socket对象向客户端发送信息：

OutputStream os = socket.getOutputStream();
String message = "Hello Client!";
os.write(message.getBytes());

示例说明

下面给出两个代码示例来帮助理解：

示例一

客户端

import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;

public class Client {
    public static void main(String[] args) throws Exception {
        Socket socket = new Socket("127.0.0.1", 8888);
        OutputStream os = socket.getOutputStream();
        String message = "Hello Server!";
        os.write(message.getBytes());

        InputStream is = socket.getInputStream();
        byte[] buffer = new byte[1024];
        int length = is.read(buffer);
        String response = new String(buffer, 0, length);
        System.out.println("Received message from server: " + response);

        socket.close();
    }
}

服务端

import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {
    public static void main(String[] args) throws Exception {
        ServerSocket serverSocket = new ServerSocket(8888);

        Socket socket = serverSocket.accept();

        InputStream is = socket.getInputStream();
        byte[] buffer = new byte[1024];
        int length = is.read(buffer);
        String message = new String(buffer, 0, length);
        System.out.println("Received message from client: " + message);

        OutputStream os = socket.getOutputStream();
        String response = "Hello Client!";
        os.write(response.getBytes());

        socket.close();
        serverSocket.close();
    }
}

示例二

客户端

import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;

public class Client {
    public static void main(String[] args) throws Exception {
        Socket socket = new Socket("127.0.0.1", 8888);
        OutputStream os = socket.getOutputStream();
        String message = "How are you?";
        os.write(message.getBytes());

        InputStream is = socket.getInputStream();
        byte[] buffer = new byte[1024];
        int length = is.read(buffer);
        String response = new String(buffer, 0, length);
        System.out.println("Received message from server: " + response);

        socket.close();
    }
}

服务端

import java.io.InputStream;
import java.io.OutputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {
    public static void main(String[] args) throws Exception {
        ServerSocket serverSocket = new ServerSocket(8888);

        Socket socket = serverSocket.accept();

        InputStream is = socket.getInputStream();
        byte[] buffer = new byte[1024];
        int length = is.read(buffer);
        String message = new String(buffer, 0, length);
        System.out.println("Received message from client: " + message);

        OutputStream os = socket.getOutputStream();
        String response = "I'm fine!";
        os.write(response.getBytes());

        socket.close();
        serverSocket.close();
    }
}

以上就是关于Java网络通信技术之简单聊天小程序的完整攻略。