Struts2中拦截器与过滤器的执行顺序

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web.xml

<?xml version="1.0" encoding="UTF-8"?><web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> <welcome-file-list> <welcome-file>login.jsp</welcome-file> </welcome-file-list> <filter> <filter-name>MyFilter</filter-name> <filter-class>filter.MyFilter</filter-class> </filter> <filter-mapping> <filter-name>MyFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <filter> <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> </web-app>

filter.MyFilter

package filter;import java.io.IOException;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() {}public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { System.out.println("请求过滤"); chain.doFilter(request, response); System.out.println("返回过滤"); }public void init(FilterConfig arg0) throws ServletException {}}

interceptor.LoginIntercepto

package interceptor;import org.apache.struts2.ServletActionContext;import com.opensymphony.xwork2.ActionInvocation;import com.opensymphony.xwork2.interceptor.AbstractInterceptor;public class LoginInterceptor extends AbstractInterceptor {private static final long serialVersionUID = -2796326480994355318L;@Overridepublic String intercept(ActionInvocation ai) throws Exception { System.out.println("请求拦截"); if(!"YOYO".equals(ServletActionContext.getRequest().getParameter("username"))){ return "login"; } String result = ai.invoke(); System.out.println("返回拦截"); return result;}}

action.LoginAction

package action;public class LoginAction {public String execute(){ System.out.println("登陆ACTION"); return "success";}}

index.jsp

<%@ page language="java" import="java.util.*" pageEncoding="ISO-8859-1"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html> <head> <title>My JSP 'index.jsp' starting page</title> </head> <body> <h3>Login</h3> <hr> <form action="Login.action" method="OST"> Name: <input type="text" name="username" /> <input type="submit" value="submit" /> </form> </body></html>

部署好后打开login.jsp，输入任意非"YOYO"字符，控制台打印出
请求过滤
请求拦截
返回过滤
说明拦截之后还会按照原路返回；

如果输入"YOYO"，则打印出
请求过滤
请求拦截
登陆ACTION
返回拦截
返回过滤

由此可以验证它的执行顺序 = =。