ext7_server.java

1) 利用InetAddress类的方法获取主机的名称和IP地址。 2) 利用URL类获取网络资源。 3) 使用Socket编程：客户机发送数据到服务器

import java.io.*;
import java.net.*;

public class Ext7_Server extends Thread
{
	static int ServerPort=5000;//服务端口5000
	public static int i=0;
	public static String[] Count=new String[10];//用来记录客户登陆情况
	private Socket Server;

	public Ext7_Server()
	{

	}

	//***********************************************************
	//运行服务器
	//************************************************************
	public void run()
	{
		ServerThread.Show("服务器端程序启动...");
        try{
        	ServerSocket serversocket=new ServerSocket(ServerPort);

          while(true)
          {

              Server=serversocket.accept();
              ServerThread ct=new ServerThread(Server);
              ct.start();
          }
      }catch(Exception   e){
          e.printStackTrace();
          ServerThread.Show("服务器端程序关闭。。。");
          System.exit(0);
      }
	}

	//*******************************************************
	//对用户进行标志
	//*******************************************************
	public static synchronized void SendMessage(String msg)
	{
		Count[i]=msg;
		i=(i+1)%10;
		Count[i]="*";//以“*”为标志
	}

	public static void main(String[] args)
	{
		Ext7_Server sp=new Ext7_Server();
		sp.start();
	}
}

//********************************************************
//服务端核心
//********************************************************
class ServerThread extends Thread
{
	private static int ii=0;
	private Socket s;
	String msg=null;
	ServerSocket serverSocket=null;
	Socket socket=null;
	BufferedReader Min=null;
	PrintWriter Mout=null;

	public ServerThread(Socket s)
	{
		this.s=s;
	}

	public void run()
	{
		try
		{
			Min=new BufferedReader(new InputStreamReader(s.getInputStream()));
			Mout=new PrintWriter(s.getOutputStream());
			SendToAll STA=new SendToAll();
			STA.start();
			msg=Min.readLine();
			ii++;
			System.out.println("有人进入了聊天室,现在有"+ii+"个人在聊天");
			while(!msg.equals("exit"))
			{
				Ext7_Server.SendMessage(msg);
				msg=Min.readLine();
			}
			if(msg.equals("exit"))
			{
				--ii;
				System.out.println("有人离开了聊天室，现在有"+ii+"个人在聊天");
				Min.close();
				Mout.close();
				s.close();
			}
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}
	}

	static void Show(String info)
	{
		System.out.println(info);
	}

	class SendToAll extends Thread
	{
		private int j=-1;
		public void run()
		{
			//cli=new Socket(5001);
			while(true)
			{
				try
				{
					sleep(500);
					if(j==-1)
					{
						if(!Ext7_Server.Count[0].equals("*"))
						{
							Mout.println(Ext7_Server.Count[0]);
							Mout.flush();
							j=1;
						}
						else
						{
							Mout.println(Ext7_Server.Count[1]);
							Mout.flush();
							j=2;
						}
					}
					while(!Ext7_Server.Count[j].equals("*"))
					{
						Mout.println(Ext7_Server.Count[j]);
						Mout.flush();
						j=(j+1)%10;
					}
				}
				catch(Exception e)
				{

				}
			}
		}
	}


}
//}