package athere.tp; 

import java.io.*;
import java.net.*;
import java.util.Date;
/**
 *  服務器實現,用線程池管理的服務器程序
 */
public class PooledDBServer{

    private int maxConnections;		//最大線程數

    private int listenPort;			//偵聽端口號

    public PooledDBServer(int port , int maxCon){
        this.listenPort = port;
        this.maxConnections = maxCon;
    }

    /**
     * 初始化線程池中的線程,創建完的每個線程處于待命的狀態,處理客戶端的請求
     */
    private void setupHandlers(){
        for(int i=0 ; i<maxConnections ; ++i){
        	//創建PooledConnectionHandle對象,該類實現了runnable接口
        	PooledConnectionHandle connectionHandle = new PooledConnectionHandle();
        	//啟動線程
        	new Thread(connectionHandle,"handle"+i).start();
        }
    }

   	/**
   	 * 套接字開始偵聽,開始接收請求
   	 */
    public void acceptConnection(){
        try{
        	System.out.println(new Date() + " Server Listened Port:" + listenPort);
            ServerSocket server = new ServerSocket(listenPort,5);
            Socket incomingSocket = null;
            while(true){
                incomingSocket  = server.accept();
                System.out.println(new Date() + " Accept a Socket:"+incomingSocket.toString());
                /* 處理連接請求:
                 * 將客戶socket傳給PooledConnectionHandle的靜態方法processRequest
                 * processRequest將socket放入請求隊列
                 */
                PooledConnectionHandle.processRequest(incomingSocket);
            }
        }catch(BindException e){
            System.out.println(new Date() + " Unable to bind to port.");
            e.printStackTrace();
        }catch(IOException e){
            System.out.println(new Date());
            e.printStackTrace();
        }
    }

    //test start
    //將server 在cmd 命令行中啟動即可調試
    public static void main(String[] args){
    	PooledDBServer tmp = new PooledDBServer(8059,20);
    	tmp.setupHandlers();
    	tmp.acceptConnection();
    }
    //test end
    
}