java内存中初始化数据字典

1.在web.xml中配置监听，注意：要配置在Spring加载之后

<context-param>
		<description>是否缓存字典（配置值：true，false）</description>
		<param-name>cache_wangxuegang</param-name>
		<param-value>true</param-value>
	</context-param>
	<context-param>
		<description>缓存字典Json变量名</description>
		<param-name>wangxuegangJsonsKey</param-name>	
		<param-value>wangxuegang</param-value>
	</context-param>
	<context-param>
		<description>缓存字典List变量名</description>
		<param-name>wangxuegangListsKey</param-name>
		<param-value>wangxuegangList</param-value>
	</context-param>
	
	<!-- Spring Context Loader Listener define -->
    <listener>
		<description>业务代码装载监听器</description>
		<listener-class>com.wangxuegang.listener.WangxuegangApplicationListener</listener-class>
	</listener>

 

2.创建WangxuegangApplicationListener类实现ServletContextListener接口

package com.wangxuegang.listener;


import java.util.List;
import java.util.Map;

import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.web.context.support.WebApplicationContextUtils;



/**
 * 
 * @Description 内存中加载数据字典
 * @author wangxuegang
 * @date 2018年11月15日 
 * @version V1.0 
 * =================Modify Record=================
 * @Modifier			@date			@Content
 *
 */
public class WangxuegangApplicationListener implements ServletContextListener  {
	
	private static final Logger logger = LoggerFactory.getLogger(WangxuegangApplicationListener.class);
	
	@Override
	public void contextInitialized(ServletContextEvent sce) {
		
		logger.info("开始加载数据缓存...");
		//获取业务Service
		//WangxuegangService wangxuegangservice = WebApplicationContextUtils.getWebApplicationContext(sce.getServletContext()).getBean(WangxuegangService.class);
		//wangxuegang(sce.getServletContext(),wangxuegangservice);
		logger.info("初始化字典数据成功...");
	}
	
	/**
	 * 
	 * @Description 查询数据库字典
	 * @author wangxuegang
	 * @date 2018年11月22日
	 * @param servletContext
	 */
	private void wangxuegang(ServletContext servletContext,WangxuegangService wangxuegangservice) {
		
		//是否开启数据字典加载缓存
		String cache =servletContext.getInitParameter("cache_wangxuegang");
		if("true".equals(cache)){
			
			//获取key
			String JsonsKey =servletContext.getInitParameter("wangxuegangJsonsKey");
			String ListsKey =servletContext.getInitParameter("wangxuegangListsKey");
			
			Wangxuegang wangxuegang = wangxuegangservice.getWangxhegang();
			List<Wangxuegang> wangxuegangList = wangxuegangservice.getWangxhegangList();
			
			servletContext.setAttribute(JsonsKey, wangxuegang);
			servletContext.setAttribute(ListsKey, wangxuegangList);
		}
		
	}

	@Override
	public void contextDestroyed(ServletContextEvent sce) {
	}
	
}

 

3.Wangxuegangcontroller层,在内存中取值

request.getSession.getServletContext().getAttribute("JsonsKey");

request.getSession.getServletContext().getAttribute("ListsKey");