傻瓜式servlet监听器简单实例

假设已经配置好java,tomcat环境

创建AppListener.java文件

import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.servlet.annotation.WebListener;
@WebListener
public class AppListener implements ServletContextListener
{
    @Override
    public void contextDestroyed(ServletContextEvent sce)
    {
    }
    @Override
    public void contextInitialized(ServletContextEvent sce)
    {
        ServletContext servletContext = sce.getServletContext()
                                        ;
        Map<String, String> countries =
            new HashMap<String, String>();
        countries.put("ca", "Canada");
        countries.put("us", "United States");
        servletContext.setAttribute("countries", countries);
    }
}
View Code

编译将.class文件放于apache-tomcat-9.0.6(Tomcat安装目录)\webapps\ROOT\WEB-INF\classes下,在WEB-INF\web-xml中添加

  <listener>
        <listener-class>AppListener</listener-class>
  </listener>

在<web-app> </web-app>标签内

创建countries.jsp文件

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<html>
<head>
<title>Country List</title>
</head>
<body>
We operate in these countries:
<ul>
<c:forEach items="${countries}" var="country">
<li>${country.value}</li>
</c:forEach>
</ul>
</body>
</html>
View Code

保存于\ROOT\jsp\中(jsp文件夹自己添加)

添加jstl-1.2.jar和javax.servlet-api-4.0.1.jar到\ROOT\WEB-INF\lib中

启动tomcat

浏览器输入http://localhost:8080/jsp/countries.jsp

可以看到

此方法只为过一把成功的瘾,具体原理和教程自行百度。

posted on 2018-04-27 19:17  子狼  阅读(174)  评论(0编辑  收藏  举报

导航