mappoolservlet.java

基于JAVA的GIS地图定义预装载模块,地图平台为MAPXTREME,可加速客户端初始化地图的时间

package com.bro.map.pool;

/**
 * <p>Title: MapService</p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2003</p>
 * <p>Company: BRO</p>
 * @author 陈顺华
 * @version 1.0
 */

import com.mapinfo.mapj.MapJ;

import javax.servlet.*;
import javax.servlet.http.*;

public class MapPoolServlet extends HttpServlet
{
	MapJPool mapPool;
	PoolThread poolThread;

	/*地图数据文件路径*/
	private String m_mapPath    = "C:\\mapxtreme\\maps\\";
	private String m_fileToLoad = "c:\\data\\world.mdf";

	/*ServletContexName，供MapService调用*/
	private String m_poolName   = "MapPool";

	/*池大小，线程睡眠时间*/
	private int    m_PoolSize   = 20;
	private long   m_delay      = 300000;

	public void init(ServletConfig cfg) throws ServletException
	{
	  super.init(cfg);
	  //ServletContextName
      String strParam = getInitParameter("ServletContextName");
      if(strParam != null)
         m_poolName = strParam;
	  //地图文件，存放table 文件的路径
      strParam = getInitParameter("mapPath");
      if(strParam != null)
         m_mapPath = strParam;
      //地图集文件
      strParam = getInitParameter("fileToLoad");
      if(strParam != null)
         m_fileToLoad = strParam;
	  //池大小
      strParam = getInitParameter("PoolSize");
      if(strParam != null)
         m_PoolSize = Integer.valueOf(strParam).intValue();
	  //线程睡眠时间
      strParam = getInitParameter("TreadDelay");
      if(strParam != null)
         m_delay = Long.valueOf(strParam).longValue();

	  mapPool    = new MapJPool(m_PoolSize , m_fileToLoad);
	  poolThread = new PoolThread(mapPool ,  m_delay);
	  poolThread.start();

	  getServletContext().setAttribute(m_poolName , this);
	  System.out.println(m_poolName + "池创建成功");
	}

	public MapJ getMapJ() throws Exception
	{
		MapJ map = null;
		if (mapPool != null)
		{
			map = mapPool.getMapJ();
		}
		return map;	
	}

	public void destroy()
	{
	  getServletContext().removeAttribute(m_poolName);
	  if (poolThread != null)
	  {
		  poolThread.stop();
		  poolThread = null;
	  }
	  if (mapPool != null)
	  {
		  mapPool.destroy();
	  }
	  super.destroy();
	}

}