java socket通信例子

java socket 通信，简易聊天功能， 

参考：http://www.cnblogs.com/feijian/p/4461087.html

   服务端：

package com.lw.socket.server;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;

public class ChatServer extends ServerSocket {

	private static final int SERVER_PORT = 8000;

	private static final String KEY = "key";

	private static boolean isPrint = false;// 是否输出消息标志
	private static List<String> user_list = new ArrayList<>();// 登录用户集合
	private static List<ServerClientThread> thread_list = new ArrayList<ServerClientThread>();// 服务器已启用线程集合
	private static LinkedList<String> message_list = new LinkedList<String>();// 存放消息队列

	/**
	 * 创建服务端Socket,创建向客户端发送消息线程,监听客户端请求并处理
	 */
	public ChatServer() throws IOException {
		super(SERVER_PORT);// 创建ServerSocket
		new PrintOutThread();// 创建向客户端发送消息线程
		new ServerReadThread();// 创建向客户端发送消息线程（服务端输入数据推送到各客户端）

		try {
			while (true) {// 监听客户端请求，启个线程处理
				Socket socket = accept();
				new ServerClientThread(socket);
			}
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			close();
		}
	}

	/**
	 * 监听是否有输出消息请求线程类,向客户端发送消息
	 */
	class PrintOutThread extends Thread {

		public PrintOutThread() {
			start();
		}

		@Override
		public void run() {
			while (true) {
				if (isPrint) {// 将缓存在队列中的消息按顺序发送到各客户端，并从队列中清除。
					String message = message_list.getFirst();
					for (ServerClientThread thread : thread_list) {
						thread.sendMessage(message);
					}
					message_list.removeFirst();
					isPrint = message_list.size() > 0 ? true : false;
				}
			}
		}
	}

	/**
	 * 服务器向各客户端发送数据的线程
	 */
	class ServerReadThread extends Thread {
		
		public ServerReadThread() {
			start();
		}
		
		@Override
		public void run() {
			BufferedReader br = null;
			try {
				while (true) {
					System.out.println("服务端发送数据输入:");
					br = new BufferedReader(new InputStreamReader(System.in));
					String send = br.readLine();
					DateFormat dateTimeformat = new SimpleDateFormat("HH:mm:ss");
					String date = dateTimeformat.format(new Date());
					message_list.addLast(date + "【系统消息】：" + send);
					isPrint = true;
				}
			} catch (Exception e) {
				e.printStackTrace();
			} finally {
				try {
					if (br != null) {
						br.close();
					}
				} catch (IOException e) {
					e.printStackTrace();
				}
			}
		}
	}

	/**
	 * 服务器线程类
	 */
	class ServerClientThread extends Thread {
		private Socket client;
		private PrintWriter writer;
		private BufferedReader reader;
		private String name;

		public ServerClientThread(Socket s) throws IOException {
			client = s;
			writer = new PrintWriter(client.getOutputStream(), true);
			reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
			String read = reader.readLine();
			if(KEY.equals(read)) {
				writer.println("成功连上聊天室,请输入你的名字：");
				start();
			}
		}

		@Override
		public void run() {
			try {
				int flag = 0;
				String line = reader.readLine();
				while (!"byeClient".equals(line)) {
					// 查看在线用户列表
					if ("showuser".equals(line)) {
						writer.println(this.listOnlineUsers());
						line = reader.readLine();
					}
					// 第一次进入，保存名字
					if (flag++ == 0) {
						name = line;
						user_list.add(name);
						thread_list.add(this);
						writer.println(name + "你好,可以开始聊天了...");
						this.pushMessage("【" + name + "】进入聊天室...");
					} else {
						this.pushMessage("【" + name + "】 say : " + line);
					}
					line = reader.readLine();
				}
				writer.println("byeClient");
			} catch (Exception e) {
				e.printStackTrace();
			} finally {// 用户退出聊天室
				try {
					client.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
				thread_list.remove(this);
				user_list.remove(name);
				pushMessage("【" + name + "】退出了聊天室");
			}
		}

		// 放入消息队列末尾，准备发送给客户端
		private void pushMessage(String msg) {
			DateFormat dateTimeformat = new SimpleDateFormat("HH:mm:ss");
			String date = dateTimeformat.format(new Date());
			message_list.addLast(date + msg);
			isPrint = true;
		}

		// 向客户端发送一条消息
		private void sendMessage(String msg) {
			writer.println(msg);
		}

		// 统计在线用户列表
		private String listOnlineUsers() {
			String s = "--- 在线用户列表 ---\015\012";
			for (int i = 0; i < user_list.size(); i++) {
				s += "[" + user_list.get(i) + "]\015\012";
			}
			s += "--------------------";
			return s;
		}
	}

	public static void main(String[] args) {
		try {
			new ChatServer().close();// 启动服务端
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}

 

   客户端：

package com.lw.socket.client;

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

public class ChatClient extends Socket {

	private static final String SERVER_IP = "127.0.0.1";
	private static final int SERVER_PORT = 8000;
	
	private static final String PASSWORD = "pwd";
	private static final String KEY = "key";

	private Socket client;
	private PrintWriter writer;
	private BufferedReader reader;

	/**
	 * 与服务器连接，并输入发送消息
	 */
	public ChatClient() throws Exception {
		super(SERVER_IP, SERVER_PORT);
		client = this;
		writer = new PrintWriter(client.getOutputStream(), true);
		reader = new BufferedReader(new InputStreamReader(client.getInputStream()));
		new readLineThread();

		System.out.println("输入正确的密码连接服务器");
		while(true) {
			BufferedReader readerIn = new BufferedReader(new InputStreamReader(System.in));
			String input = readerIn.readLine();
			if(PASSWORD.equals(input)) {
				writer.println(KEY);
				break;
			} else {
				System.out.println("输入错误，请重新输入！");
			}
		}

		while (true) {
			reader = new BufferedReader(new InputStreamReader(System.in));
			String input = reader.readLine();
			writer.println(input);
		}
	}

	/**
	 * 用于监听服务器端向客户端发送消息线程类
	 */
	class readLineThread extends Thread {

		private BufferedReader buff;

		public readLineThread() {
			try {
				buff = new BufferedReader(new InputStreamReader(client.getInputStream()));
				start();
			} catch (Exception e) {
				e.printStackTrace();
			}
		}

		@Override
		public void run() {
			try {
				while (true) {
					String result = buff.readLine();
					if ("byeClient".equals(result)) {// 客户端申请退出，服务端返回确认退出
						break;
					} else {// 输出服务端发送消息
						System.out.println(result);
					}
				}
				reader.close();
				writer.close();
				client.close();
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	}

	public static void main(String[] args) {
		try {
			new ChatClient().close();// 启动客户端
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}