关于Socket套接字的一些基本知识与认识可以参见上一篇或自行查阅。
ServerSocket和Socket实现群聊与私聊涉及到多线程编程,实现过程的重点是利用Socket通信的原理,即不断的在服务端和客户端创建输入输出流来相互传递、交换数据等以达到通信的目的。具体实现如下:
服务端:
import java.io.*;
import java.net.*;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
public class TCPServer {
private ServerSocket serverSocket;
/**
* 创建线程池来管理客户端的连接线程
* 避免系统资源过度浪费
*/
private ExecutorService exec;
// 存放客户端之间私聊的信息
private Map<String,PrintWriter> storeInfo;
public TCPServer() {
try {
serverSocket = new ServerSocket(6789);
storeInfo = new HashMap<String, PrintWriter>();
exec = Executors.newCachedThreadPool();
} catch (Exception e) {
e.printStackTrace();
}
}
// 将客户端的信息以Map形式存入集合中
private void putIn(String key,PrintWriter value) {
synchronized(this) {
storeInfo.put(key, value);
}
}
// 将给定的输出流从共享集合中删除
private synchronized void remove(String key) {
storeInfo.remove(key);
System.out.println("当前在线人数为:"+ storeInfo.size());
}
// 将给定的消息转发给所有客户端
private synchronized void sendToAll(String message) {
for(PrintWriter out: storeInfo.values()) {
out.println(message);
}
}
// 将给定的消息转发给私聊的客户端
private synchronized void sendToSomeone(String name,String message) {
PrintWriter pw = storeInfo.get(name); //将对应客户端的聊天信息取出作为私聊内容发送出去
if(pw != null) pw.println(message);
}
public void start() {
try {
while(true) {
System.out.println("等待客户端连接... ... ");
Socket socket = serverSocket.accept();
// 获取客户端的ip地址
InetAddress address = socket.getInetAddress();
System.out.println("客户端:“" + address.getHostAddress() + "”连接成功! ");
/*
* 启动一个线程,由线程来处理客户端的请求,这样可以再次监听
* 下一个客户端的连接
*/
exec.execute(new ListenrClient(socket)); //通过线程池来分配线程
}
} catch(Exception e) {
e.printStackTrace();
}
}
/**
* 该线程体用来处理给定的某一个客户端的消息,循环接收客户端发送
* 的每一个字符串,并输出到控制台
*/
class ListenrClient implements Runnable {
private Socket socket;
private String name;
public ListenrClient(Socket socket) {
this.socket = socket;
}
// 创建内部类来获取昵称
private String getName() throws Exception {
try {
//服务端的输入流读取客户端发送来的昵称输出流
BufferedReader bReader = new BufferedReader(
new InputStreamReader(socket.getInputStream(), "UTF-8"));
//服务端将昵称验证结果通过自身的输出流发送给客户端
PrintWriter ipw = new PrintWriter(
new OutputStreamWriter(socket.getOutputStream(), "UTF-8"),true);
//读取客户端发来的昵称
while(true) {
String nameString = bReader.readLine();
if ((nameString.trim().length() == 0) || storeInfo.containsKey(nameString)) {
ipw.println("FAIL");
} else {
ipw.println("OK");
return nameString;
}
}
} catch(Exception e) {
throw e;
}
}
@Override
public void run() {
try {
/*
* 通过客户端的Socket获取客户端的输出流
* 用来将消息发送给客户端
*/
PrintWriter pw = new PrintWriter(
new OutputStreamWriter(socket.getOutputStream(), "UTF-8"), true);
/*
* 将客户昵称和其所说的内容存入共享集合HashMap中
*/
name = getName();
putIn(name, pw);
Thread.sleep(100);
// 服务端通知所有客户端,某用户上线
sendToAll("[系统通知] “" + name + "”已上线");
/*
* 通过客户端的Socket获取输入流
* 读取客户端发送来的信息
*/
BufferedReader bReader = new BufferedReader(
new InputStreamReader(socket.getInputStream(), "UTF-8"));
String msgString = null;
while((msgString = bReader.readLine()) != null) {
// 检验是否为私聊(格式:@昵称:内容)
if(msgString.startsWith("@")) {
int index = msgString.indexOf(":");
if(index >= 0) {
//获取昵称
String theName = msgString.substring(1, index);
String info = msgString.substring(index+1, msgString.length());
info = name + ":"+ info;
//将私聊信息发送出去
sendToSomeone(theName, info);
continue;
}
}
// 遍历所有输出流,将该客户端发送的信息转发给所有客户端
System.out.println(name+":"+ msgString);
sendToAll(name+":"+ msgString);
}
} catch (Exception e) {
// e.printStackTrace();
} finally {
remove(name);
// 通知所有客户端,某某客户已经下线
sendToAll("[系统通知] "+name + "已经下线了。");
if(socket!=null) {
try {
socket.close();
} catch(IOException e) {
e.printStackTrace();
}
}
}
}
}
public static void main(String[] args) {
TCPServer server = new TCPServer();
server.start();
}
}
客户端:
import java.io.*;
import java.net.*;
import java.util.Scanner;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
public class TCPClient {
static private Socket clientSocket;
public TCPClient() {}
public static void main(String[] args) throws Exception {
Scanner scanner = new Scanner(System.in);
String serverIP;
System.out.println("请设置服务器IP:");
serverIP = scanner.next();
clientSocket = new Socket(serverIP, 6789);
TCPClient client = new TCPClient();
client.start();
}
public void start() {
try {
Scanner scanner = new Scanner(System.in);
setName(scanner);
// 接收服务器端发送过来的信息的线程启动
ExecutorService exec = Executors.newCachedThreadPool();
exec.execute(new ListenrServser());
// 建立输出流,给服务端发信息
PrintWriter pw = new PrintWriter(
new OutputStreamWriter(clientSocket.getOutputStream(), "UTF-8"), true);
while(true) {
pw.println(scanner.nextLine());
}
} catch(Exception e) {
e.printStackTrace();
} finally {
if (clientSocket !=null) {
try {
clientSocket.close();
} catch(IOException e) {
e.printStackTrace();
}
}
}
}
private void setName(Scanner scan) throws Exception {
String name;
//创建输出流
PrintWriter pw = new PrintWriter(
new OutputStreamWriter(clientSocket.getOutputStream(), "UTF-8"),true);
//创建输入流
BufferedReader br = new BufferedReader(
new InputStreamReader(clientSocket.getInputStream(),"UTF-8"));
while(true) {
System.out.println("请创建您的昵称:");
name = scan.nextLine();
if (name.trim().equals("")) {
System.out.println("昵称不得为空");
} else {
pw.println(name);
String pass = br.readLine();
if (pass != null && (!pass.equals("OK"))) {
System.out.println("昵称已经被占用,请重新输入:");
} else {
System.out.println("昵称“"+name+"”已设置成功,可以开始聊天了");
break;
}
}
}
}
// 循环读取服务端发送过来的信息并输出到客户端的控制台
class ListenrServser implements Runnable {
@Override
public void run() {
try {
BufferedReader br = new BufferedReader(
new InputStreamReader(clientSocket.getInputStream(), "UTF-8"));
String msgString;
while((msgString = br.readLine())!= null) {
System.out.println(msgString);
}
} catch(Exception e) {
e.printStackTrace();
}
}
}
}
运行结果:
开始自己的实现也不是很完整,后来也是借鉴别人比较好的思想后完善的,权当分享。
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