html layui +thymeleaf 内容是博客分类（自己正在写的这个博客需要用到这个）
<select id="blogTypeId" lay-verify="required" name="blogTypeId"lay-search><option value="selected"></option><option th:each="blogType:${application.blogTypeList}"th:value="${blogType.id}" th:text="${blogType.typeName}">博客类型A</option></select>监听器
实现 ServletContextListener接口达到初始化加载sleect option
但是每次更新需要重服务器，太麻烦，修改也不能及时自己更新
因为这个数据是放在application中的所有可以再实现一个接口ServletContextAttributeListener，再监听修改操作
监听器
package cn.edu.jxnu.blog.listener;import java.util.List;import javax.servlet.ServletContext;
import javax.servlet.ServletContextAttributeEvent;
import javax.servlet.ServletContextAttributeListener;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;import org.springframework.context.ApplicationContext;
import org.springframework.stereotype.Component;
import org.springframework.web.context.support.WebApplicationContextUtils;import cn.edu.jxnu.blog.domin.BlogType;
import cn.edu.jxnu.blog.service.BlogTypeService;@Component
/*** @Description 监听程序初始化*/
public class InitBlogTypeData implements ServletContextAttributeListener,ServletContextListener {private static ApplicationContext applicationContext;public void contextInitialized(ServletContextEvent sce) {// 先获取servlet上下文ServletContext application = sce.getServletContext();// 获取spring web上下文applicationContext = WebApplicationContextUtils.getWebApplicationContext(application);// System.out.println("上下文："+applicationContext);BlogTypeService blogTypeService = applicationContext.getBean(BlogTypeService.class);// System.out.println("blogTypeService="+blogTypeService);List<BlogType> blogTypeList = blogTypeService.getBlogTypeData();application.setAttribute("blogTypeList", blogTypeList);System.out.println("ServletContextListener---（contextInitialized）...");}public void contextDestroyed(ServletContextEvent sce) {System.out.println("ServletContextListener---（contextDestroyed）...");}@Overridepublic void attributeAdded(ServletContextAttributeEvent args) {System.out.println("ServletContextAttributeListener---（attributeAdded）...");}/*** 后台更新分类数据的时候将清空ServletContext,此方法将监听，并重新添加blogTypeList*/@Overridepublic void attributeRemoved(ServletContextAttributeEvent args) {// 先获取servlet上下文ServletContext application = args.getServletContext();// 获取spring web上下文applicationContext = WebApplicationContextUtils.getWebApplicationContext(application);// System.out.println("上下文："+applicationContext);BlogTypeService blogTypeService = applicationContext.getBean(BlogTypeService.class);// System.out.println("blogTypeService="+blogTypeService);List<BlogType> blogTypeList = blogTypeService.getBlogTypeData();application.setAttribute("blogTypeList", blogTypeList);System.out.println("ServletContextAttributeListener---（attributeRemoved）...");}@Overridepublic void attributeReplaced(ServletContextAttributeEvent args) {System.out.println("ServletContextAttributeListener---（attributeReplaced）...");}}controller方法签名类似这种，传入一个request
@RequestMapping(value = "/delete")public String deleteBlog(@RequestParam(value = "ids", required = false) String ids,HttpServletResponse response, HttpServletRequest httpServletRequest)在请求返回的同时触发监听器事件，清空或者改变application键值。 这里是选择直接删除ServletContext application = httpServletRequest.getServletContext();application.removeAttribute("blogTypeList");