简单的网络多客户端通信例子

一个简单的多客户端回答问题服务端，可以自动记录hashmap里没有的问题。
代码很简单，容易看懂 就不做解释了

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.HashMap;
import java.util.Scanner;


public class ServerTest {


	public static void main(String[] args) {
		ServerTest serverTest=new ServerTest();
		HashMap<String, String> quesMap = serverTest.creatMap();

		try {
			int i=1;
			ServerSocket serverSocket=new ServerSocket(8189);
			System.out.println("服务端启动，等待客户端连接...");
			while (true) {
				Socket incoming=serverSocket.accept();
				System.out.println("连接数 "+i);
				Runnable r =new ThreadHandler(incoming,quesMap);
				Thread t = new Thread(r);
				t.start();
				i++;
			}
			
		} catch (IOException e) {
			e.printStackTrace();
		}

	}
	
	public HashMap<String, String> creatMap(){
		HashMap<String, String> quesMap= new HashMap<String, String>();
		quesMap.put("what is your name?", "my name is otto");
                quesMap.put("what is your age?", "i'm 24");
		return quesMap;
	}

}

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.HashMap;
import java.util.Scanner;

public class ThreadHandler implements Runnable{

	public ThreadHandler(Socket i,HashMap<String, String> hashMap){
		this.hashMap=hashMap;
		this.incoming=i;
	}


	public void run() {
		try{
		try {
			InputStream inStream = incoming.getInputStream();
			OutputStream outStream = incoming.getOutputStream();
			
			Scanner inScanner= new Scanner(inStream);
			PrintWriter out = new PrintWriter(outStream,true); 
			
			out.println("you can type EXIT to exit!");
			out.println("**************************");
			System.out.println("已经链接！");
			boolean done = false;
			boolean locked = false;
			String key=null;
			while (!done && inScanner.hasNextLine()) {
					String line=inScanner.nextLine();
					System.out.println(line);
					if(!locked && hashMap.containsKey(line)){
						out.println("Echo :"+hashMap.get(line));
						
					}else{
						if(locked==true){
						hashMap.put(key,line);
						locked=false;
						out.println("Echo:问题和答案已经保存！");
						}else {
							out.println("Echo:抱歉，目前只能回答有限问题！");
							out.println("但是系统将记录你的问题，如知道答案，请输入");
							key=line;
							  locked = true;
						}
						
					 
					}
					 if(line.trim().equals("EXIT"))done=true;
			
				}
			
		
			} finally{
				incoming.close();
			}
		}catch (IOException e) {
		e.printStackTrace();
		}
		}

	private Socket incoming;
	private HashMap<String, String> hashMap;
}