Listener:
import java.util.Enumeration; import javax.servlet.ServletContext; import javax.servlet.ServletContextEvent; import javax.servlet.ServletContextListener; public class MyListener implements ServletContextListener { public void contextDestroyed(ServletContextEvent sce) { System.out.println("Listener Destory"); } @SuppressWarnings("unchecked") public void contextInitialized(ServletContextEvent sce) { System.out.println("Listener Initialize"); ServletContext servletContext = sce.getServletContext(); Enumeration<String> names = servletContext.getInitParameterNames(); while (names.hasMoreElements()) { String name = names.nextElement(); String value = servletContext.getInitParameter(name); System.out.println("param name : " + name + ",param value : " + value); } } }
Filter:
import java.io.IOException; import java.util.Enumeration; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; public class MyFilter implements Filter { public void destroy() { System.out.println("Filter destory"); } public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { chain.doFilter(request, response); } @SuppressWarnings("unchecked") public void init(FilterConfig filterConfig) throws ServletException { System.out.println("Filter init"); Enumeration<String> names = filterConfig.getInitParameterNames(); while (names.hasMoreElements()) { String name = names.nextElement(); String value = filterConfig.getInitParameter(name); System.out.println("param name : " + name + ",param value : " + value); } } }
Servlet:
import java.io.IOException; import java.util.Enumeration; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; @SuppressWarnings("serial") public class MyServlet extends HttpServlet{ @Override protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { doPost(req, resp); } @SuppressWarnings("unchecked") @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { Enumeration<String> names=this.getInitParameterNames(); while(names.hasMoreElements()){ String name=names.nextElement(); String value=this.getInitParameter(name); System.out.println("param name : " + name + ",param value : " + value); } } }
web.xml配置
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <context-param> <param-name>servlet context param</param-name> <param-value>servlet容器值</param-value> </context-param> <filter> <filter-name>myFilter</filter-name> <filter-class>MyFilter</filter-class> <init-param> <param-name>filter param</param-name> <param-value>过滤器值</param-value> </init-param> </filter> <filter-mapping> <filter-name>myFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <servlet> <servlet-name>myServlet</servlet-name> <servlet-class>MyServlet</servlet-class> <init-param> <param-name>servlet param</param-name> <param-value>servlet初始值</param-value> </init-param> </servlet> <servlet-mapping> <servlet-name>myServlet</servlet-name> <url-pattern>/myServlet</url-pattern> </servlet-mapping> <listener> <listener-class>MyListener</listener-class> </listener> </web-app>