一个简单的java socket程序

只有一个客户端的socket程序
服务器端程序：

package socketdemo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class MyServer {
	public static void main(String[] args) throws IOException {
		ServerSocket server = new ServerSocket(8800);
		Socket client = server.accept();
		BufferedReader in = new BufferedReader(new InputStreamReader(client
				.getInputStream()));
		PrintWriter out = new PrintWriter(client.getOutputStream());
		while (true) {
			String str = in.readLine();
			System.out.println(str); // 读取客户端，写入服务器端
			out.println("has receive....");// 写入客户端
			out.flush();
			if (str.equals("end"))
				break;
		}
		client.close();
	}
}

其中8800是端口号，可以任意指定一个系统没有被占用的端口号即可

客户端程序：

package socketdemo;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;

public class MyClient {
	static Socket server;

	public static void main(String[] args) throws Exception {
		server = new Socket(InetAddress.getLocalHost(), 8800);   //服务器的主机名（即ip地址）和端口号
		BufferedReader in = new BufferedReader(new InputStreamReader(server
				.getInputStream()));
		PrintWriter out = new PrintWriter(server.getOutputStream());
		BufferedReader wt = new BufferedReader(new InputStreamReader(System.in));

		while (true) {
			String str = wt.readLine();
			out.println(str);// 写入服务端
			out.flush();
			if (str.equals("end")) {
				break;
			}
			System.out.println(in.readLine()); // 读取服务器端，写入客户端，has receiving
		}
		server.close();
	}
}

执行时，可以在一台主机上执行，也可在两台主机执行，只要指定好ip地址和端口号即可。先执行服务器端程序，再开启客户端，客户端每输入一个字符串，都会在服务器端显示，直到客户端输入end，结束通信。。

多客户端程序，客户端程序不变，服务器端程序如下：

package socketdemo;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class MultiUserServer extends Thread { // 多客户端的服务器程序
	private Socket client;

	public MultiUserServer(Socket c) {
		this.client = c;
	}

	public void run() {
		try {
			BufferedReader in = new BufferedReader(new InputStreamReader(client
					.getInputStream()));
			PrintWriter out = new PrintWriter(client.getOutputStream());
			// Mutil User but can't parallel
			while (true) {
				String str = in.readLine();
				System.out.println(str);
				out.println("has receive....");
				out.flush();
				if (str.equals("end"))
					break;
			}
			client.close();
		} catch (IOException ex) {
		} finally {

		}
	}

	public static void main(String[] args) throws IOException {
		ServerSocket server = new ServerSocket(8800);
		while (true) {
			// transfer location change Single User or Multi User
			MultiUserServer mu = new MultiUserServer(server.accept());
			mu.start();
		}
	}
}