IDEA 2018.2 集成开发工具。
1、用户上线，向服务器通知并注册。
2、同局域网下，所有注册用户可以进行群聊。
3、同局域网下，所有用户可与任意已注册用户进行私聊。
4、用户下线，通知服务器，服务器更新信息。
1、服务器端实例化一个ServerSocket对象，调用accept方法等待客户端连接到服务器。
2、客户端实例化 Socket 对象，并使用构造方法与服务器建立链接。
3、服务器端根据客户端输入信息，辨别客户端请求的功能从而做出相应响应。
为了能够高效的处理客户端的请求，在服务器端使用多线程处理客户端请求。并且使用 ConcurrentHashMap 来存储所有注册过的客户端。
服务器端：
import java.io.IOException;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;
import java.util.concurrent.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class ManyThreadServer {
//存储所有注册的客户端
private static Map<String, Socket> clientMap = new ConcurrentHashMap<String,Socket>();
//具体的处理每个客户端的请求
private static class ExcuteClient implements Runnable{
private Socket client;
public ExcuteClient(Socket client) {
this.client = client;
}
@Override
public void run() {
try {
//获取客户端的输出流，读取客户端消息，并处理
Scanner in = new Scanner(client.getInputStream());
String strFromClient;
while(true){
if(in.hasNextLine()){
strFromClient = in.nextLine();
//在Windows下默认换行是：\r\n,所以把\r要转换为空字符串
Pattern pattern = Pattern.compile("\r");
Matcher matcher = pattern.matcher(strFromClient);
strFromClient = matcher.replaceAll("");
//注册流程
if(strFromClient.startsWith("useName")){
String useName = strFromClient.split("\\:")[1];
registerUser(useName,client);
continue;
}
//群聊功能
if(strFromClient.startsWith("G")){
String msg = strFromClient.split("\\:")[1];
groupChat(msg,client);
continue;
}
//私聊功能
if(strFromClient.startsWith("P")){
String userName = strFromClient.split("\\:")[1].split("-")[0];
String msg = strFromClient.split("\\:")[1].split("-")[1];
privateChat(userName,msg,client);
continue;
}
//用户退出
if(strFromClient.startsWith("B")){
String userName = null;
//根据Socket找到UserName
for(String keyName : clientMap.keySet()){
if(clientMap.get(keyName).equals(client)){
userName = keyName;
}
}
System.out.println("用户" + userName + "下线了。。。");
clientMap.remove(userName);
System.out.println("当前共有用户" + clientMap.size() + "人");
continue;
}
else{
PrintStream out = new PrintStream(client.getOutputStream(),true,"UTF-8");
out.println("输入错误。。。");
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
private void registerUser(String name,Socket client){
System.out.println("用户：" + name + "已上线！");
clientMap.put(name,client);
System.out.println("当前在线人数：" + clientMap.size() + "人！");
//既然是用户在注册，所以这里服务器通知用户注册结果
try {
PrintStream out = new PrintStream(client.getOutputStream(),true,"UTF-8");
out.println("用户注册成功！");
} catch (IOException e) {
e.printStackTrace();
}
}
private void groupChat(String msg,Socket client){
//取出clientMap中所有的Entry对象，遍历每个用户，并且发送消息
Set<Map.Entry<String,Socket>> clientSet = clientMap.entrySet();
for(Map.Entry<String,Socket> entry:clientSet){
try {
Socket socket = entry.getValue();
//取得输出流，向客户端发送消息
PrintStream out = new PrintStream(socket.getOutputStream(),true,"UTF-8");
out.println("由端口号为"+ client.getPort() + "发来的群聊消息：" + msg);
} catch (IOException e) {
e.printStackTrace();
}
}
}
private void privateChat(String userName,String msg,Socket client){
Socket privateSocket = clientMap.get(userName);
try {
PrintStream out = new PrintStream(privateSocket.getOutputStream(),true,"UTF-8");
out.println("由端口号为：" + client.getPort() + "发来的消息：" + msg);
} catch (IOException e) {
e.printStackTrace();
}
}
}
public static void main(String[] args)throws Exception{
//为了提高效率，这里使用多线程进行处理
ExecutorService executorService = Executors.newFixedThreadPool(30);
//实例化ServerSocket对象，并指定IP为本地主机，端口号为6666
ServerSocket serverSocket = new ServerSocket(6666);
for(int i = 0; i < 30;i++){
System.out.println("等待用户连接。。。");
//等待客户端连接服务器
Socket client = serverSocket.accept();
System.out.println("有客户端连接，端口号为：" + client.getPort());
//启动线程，并处理客户端请求
executorService.submit(new ExcuteClient(client));
}
//关闭线程，关闭服务器
executorService.shutdown();
serverSocket.close();
}
}客户端：
import java.io.IOException;
import java.io.PrintStream;
import java.net.Socket;
import java.util.Scanner;
/**
* 接收服务端发来的消息
*/
class FromServer implements Runnable{
Socket client;
public FromServer(Socket client){
this.client = client;
}
@Override
public void run() {
try {
Scanner in = new Scanner(client.getInputStream());
while (true) {
if (in.hasNextLine()) {
System.out.println("服务器：" + in.nextLine());
}
//判断客户端是否退出，如果推出，跳出循环，并关闭流
if (client.isClosed()) {
System.out.println("客户端关闭。。。");
break;
}
}
in.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
/**
* 向服务端发出消息
*/
class ToServer implements Runnable{
Socket client;
public ToServer(Socket client){
this.client = client;
}
@Override
public void run() {
try {
Scanner scanner = new Scanner(System.in);
PrintStream out = new PrintStream(client.getOutputStream(),true,"UTF-8");
while (true) {
System.out.println("请输入信息：");
String strToserver;
if(scanner.hasNextLine()){
strToserver = scanner.nextLine().trim();
out.println(strToserver);
//客户端退出标志：B
if(strToserver.startsWith("B")){
System.out.println("客户端退出。。。");
scanner.close();
out.close();
client.close();
break;
}
}
}
} catch (IOException e) {
e.printStackTrace();
}
}
}
public class ManyThreadClient {
public static void main(String[] args){
try {
//实例化Socket对象，与服务器建立连接
Socket client = new Socket("127.0.0.1",6666);
//为了发送消息和接收消息可以同时进行，使用多线程进行处理
Thread thread1 = new Thread(new FromServer(client));
Thread thread2 = new Thread(new ToServer(client));
thread1.start();
thread2.start();
} catch (IOException e) {
e.printStackTrace();
}
}
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