Classe Interceptor no Struts 1

<?xml version="1.0" encoding="ISO-8859-1"?>

<!DOCTYPE securityfilter-config PUBLIC
    "-//SecurityFilter.org//DTD Security Filter Configuration 2.0//EN"
    "http://www.securityfilter.org/dtd/securityfilter-config_2_0.dtd">

<securityfilter-config>


    <security-constraint>
        <web-resource-collection>
            <web-resource-name>Application Web</web-resource-name>
            <url-pattern>/*</url-pattern>
        </web-resource-collection>
        <auth-constraint>
            <role-name>usuario</role-name>
        </auth-constraint>
    </security-constraint>

    <login-config>
        <auth-method>FORM</auth-method>
        <form-login-config>
         <!-- login form -->
            <form-login-page>/login.jsp</form-login-page>
         <!-- login error page -->
            <form-error-page>/login.jsp</form-error-page>
         <!-- send users here on spontaneous login submittal -->
            <form-default-page>/novo.jsp</form-default-page>
        </form-login-config>
    </login-config>


    <realm className="org.securityfilter.realm.catalina.CatalinaRealmAdapter"/>

    <realm className="com.caelum.struts.security.SecurityFilterRealm"/>

</securityfilter-config>

<filter>
        <filter-name>Security Filter</filter-name>
        <filter-class>org.securityfilter.filter.SecurityFilter</filter-class>
        <init-param>
            <param-name>config</param-name>
            <param-value>/WEB-INF/securityfilter-config.xml</param-value>
        </init-param>
        <init-param>
            <param-name>validate</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>

    <filter-mapping>
        <filter-name>Security Filter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package com.caelum.struts.security;

import java.security.Principal;
import java.util.ArrayList;
import org.apache.catalina.realm.GenericPrincipal;
import org.apache.catalina.realm.RealmBase;

/**
 *
 * @author HOUSE
 */
public class SecurityFilterRealm extends RealmBase {

    @Override
    protected String getName() {
        return "RealmBase";
    }

    @Override
    protected String getPassword(String login) {
       return "senha";  
  }

    @Override
    protected Principal getPrincipal(String login) {
        ArrayList roleList = new ArrayList();
        roleList.add("usuario");
        return new GenericPrincipal(this, login, getPassword(login), roleList);
    }
}