Listener Filter Servlet回顾

这是简单的案例，代码如下：
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>

评论

1 楼 lijiejava 2011-10-25  

顶一个~~~~