<?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">
    <!-- 其他拦截器 -->
    <!-- 引入struts核心过滤器 -->
    <filter>
        <filter-name>struts2</filter-name>
        <filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>
    <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list>
</web-app>

package cn.itcast.a_config;
import com.opensymphony.xwork2.ActionSupport;
public class UserAction extends ActionSupport {
 // Action中业务处理方法
 public String login() {
  System.out.println("UserAction.login()");
 return "success";
 }
}

package cn.itcast.a_config;
import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionSupport;
public class UserAction implements Action {
 // Action中业务处理方法
 public String login() {
  System.out.println("UserAction.login()");
  return "success";
 }
 @Override
 public String execute() throws Exception {
  return null;
 }
}

package cn.itcast.a_config;
import com.opensymphony.xwork2.Action;
import com.opensymphony.xwork2.ActionSupport;
public class UserAction {
 private String userName;
 public void setUserName(String userName) {
  this.userName = userName;
 }
 // Action中业务处理方法
 public String login() {
  System.out.println("UserAction.login()" + userName);
  return "login";
 }
 public String register() {
  System.out.println("register()" + userName);
  return "register";
 }
}

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN"
    "http://struts.apache.org/dtds/struts-2.3.dtd">
<struts>
    <package name="config" namespace="/" extends="struts-default">
    <action name="login" class="cn.a_config.UserAction" method="login">
            <result name="success">/index.jsp</result>
    </action>
    </package>
</struts>