Skip Java Filter based on Condition

Question

I have looked in to How to skip a filter in the filter chain in java and followed the solution but this didn't help.

I have three filters in my web.xml. Struts filter, custom filter and IAM Agent filter in this order. I want to skip IAM filter based on some condition. I do not have control on IAM filter its external peace of code. So when ever the front end parameter says that the usertype is internal I need to call IAM agent filter else I need to skip this filter.

Web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app 
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns="http://java.sun.com/xml/ns/javaee" 
xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" 
id="WebApp_ID" 
version="2.5">
<display-name>App</display-name>
<!-- Struts2 Filter -->
<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>*.action</url-pattern>
</filter-mapping>
 <!-- Custom App Filter for Handling Internal And External User-->
<filter>
   <filter-name>UserType</filter-name>
   <filter-class>com.App.web.filter.LoginFilter</filter-class>
</filter>
<filter-mapping>
   <filter-name>UserType</filter-name>
   <url-pattern>/*</url-pattern>
</filter-mapping>

<!-- IAM Filter for Internal Users only-->
<filter>
   <filter-name>Agent</filter-name>
   <filter-class>com.sun.identity.agents.filter.AmAgentFilter</filter-class>
</filter>
<filter-mapping>
   <filter-name>Agent</filter-name>
   <url-pattern>/*</url-pattern>
</filter-mapping>   

<welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<listener>
    <listener-class>org.apache.tiles.web.startup.TilesListener</listener-class>
</listener>
<listener> 
    <listener-class>com.App.init.InitListener</listener-class>
</listener>
<context-param>
    <param-name>org.apache.tiles.impl.BasicTilesContainer.DEFINITIONS_CONFIG</param-name>
    <param-value>/WEB-INF/tiles.xml</param-value>
</context-param>

<!-- Web Service -->
<servlet>
    <servlet-name>EventManagementWS</servlet-name>
    <servlet-class>com.App.eventmanagement.ws.EventManagementWS</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
    <servlet-name>EventManagementWS</servlet-name>
    <url-pattern>/EventManagementWS</url-pattern>
</servlet-mapping>
<resource-ref>
       <res-ref-name>url/ConfigProperty</res-ref-name>
       <res-type>java.net.URL</res-type>
       <res-auth>Container</res-auth>
       <res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>

I am using RequestDispatcher#forward(), but I not getting anything in my index.jsp page output, just a blank page. The css files are giving 404 error. When I was using Struts tag it gave error

Uncaught exception created in one of the service methods of the servlet /index.jsp in application App. Exception created: The Struts dispatcher cannot be found.  This is usually caused by using Struts tags without the associated filter. Struts tags are only usable when the request has passed through its servlet filter, which initializes the Struts dispatcher needed for this tag.

So i removed S tag and used hard coding, but now I am getting 404 error in all css which i was trying to include.

I feel as if the forward is not working fine.

Java Filter Code:

package com.App.web.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;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.apache.commons.lang.StringUtils;

import com.App.constant.Constant;
import com.App.init.WIMSInitListener;
import com.App.log.WIMSMessageLogger;

public class LoginFilter implements Filter{

FilterConfig _filterConfig = null;
@Override
public void destroy(){
    // TODO Auto-generated method stub

}

@Override
public void doFilter(ServletRequest request, ServletResponse response, 
       FilterChain filterChain) throws IOException, ServletException{
    // Check IAM is enabled
    if (InitListener.isIAMEnabled()){
        HttpSession session = httpRequest.getSession();
        String userType = (String) session.getAttribute(Constant.USER_TYPE);
        if(userType == null || "".equals(userType)){
            MessageLogger.putMessageLog("User type is null : First Request" + userType, getClass());
            userType = request.getParameter(Constant.USER_TYPE);
            session.setAttribute(Constant.USER_TYPE, userType);
            request.getRequestDispatcher(((HttpServletRequest)request).getServletPath() + 
                    StringUtils.defaultString(((HttpServletRequest)request).getPathInfo()))
                        .forward(request, response);

        }
        if("external".equals(userType)){
            MessageLogger.putMessageLog("External User" + userType, getClass());
            request.getRequestDispatcher(((HttpServletRequest)request).getServletPath() + 
                    StringUtils.defaultString(((HttpServletRequest)request).getPathInfo()))
                        .forward(request, response);

        }
        else if("internal".equals(userType)){
            MessageLogger.putMessageLog("Internal User" + userType, getClass());
            //IAM Filter com.sun.identity.agents.filter.AmAgentFilter
            filterChain.doFilter(request, response);
        }
   }
   //Its always External User
   else{
       MessageLogger.putMessageLog("User IAM Not Enabled", getClass());
       request.getRequestDispatcher(((HttpServletRequest)request).getServletPath() + 
               StringUtils.defaultString(((HttpServletRequest)request).getPathInfo()) )
                      .forward(request, response);

   }
}

@Override
public void init(FilterConfig filterConfig) throws ServletException{
    this._filterConfig = filterConfig;
} 
}

Index.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01     Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>App</title>
<link rel="stylesheet" type="text/css" media="screen"
href="/App/css/common.css" />
<link rel="stylesheet" type="text/css" media="screen"
href="/App/css/rcorp.css" />
<link rel="stylesheet" type="text/css" media="all"
href="/App/css/style.css" />
<link rel="stylesheet" type="text/css" media="all"
href="/App/css/rcorp.css" />
<link rel="stylesheet" type="text/css" media="all"
href="/App/css/default.css" />
<script type="text/javascript">
function selectUserType(){
var frm = document.forms["UserTypeForm"];
if(document.getElementById("userTypeInternal").checked){
    //frm.action='<s:url action="loginAction.action?usertype=internal" namespace="" />';
    frm.action='/App/loginAction.action?usertype=internal';
}
else{
    //frm.action='<s:url action="loginAction.action?usertype=external" namespace="" />';
    frm.action='/App/loginAction.action?usertype=external';
}   
frm.target='_parent';
frm.submit();
}
function checkUserType(){   
//var userType = '<s:property value="#session.usertype" />';
var userType = '<%= session.getAttribute("usertype") %>';
if(userType == 'internal'){
    //frm.action='<s:url action="loginAction.action?usertype=internal" namespace="" />';
    frm.action='/App/loginAction.action?usertype=internal';
    frm.target='_parent';
    frm.submit();
}
else if(userType == 'external'){
    //frm.action='<s:url action="loginAction.action?usertype=external" namespace="" />';
    frm.action='/App/loginAction.action?usertype=external';
    frm.target='_parent';
    frm.submit();
}
}
</script>
</head>
<body onload="javascript:checkUserType();">
<form method="POST" action="loginAction.action" name="UserTypeForm">
    <div id="display_option"
        style="DISPLAY: none; position: absolute; top: 40%; width: 100%;"
        align="center">
        <div class="rcorp-tbl">
            <div style="width: 340px;">
                <div style="border: 1px solid #6da6fe; padding: 5px;">
                    <table style="background-color: #f0f8ff;" cellspacing=2 border=0>
                        <tr>
                            <td class="t-cellsecnowrap">Select User type:</td>
                            <td>
                            <td class="t-cell">
                                <div id="wwgrp_systemType" class="wwgrp">
                                    <div id="wwctrl_systemType" class="wwctrl">
                                        <input type="radio" name="UserType" id="internal" value="internal" checked/>
                                            <label for="userTypeInternal">Internal User (Sydney Trains Users)</label>&nbsp; 
                                        <input type="radio" name="userType" id="external" value="external"/>
                                            <label for="userTypeExternal">External User</label>&nbsp;&nbsp;&nbsp;&nbsp;
                                        <input type="button" name="applyBtn" id="applyBtn" class="btn" value="Go" title="Go" onclick="javascript:selectUserType();"/>
                                    </div>
                                </div>
                            </td>
                        </tr>
                    </table>
                </div>
            </div>
        </div>
    </div>
</form>
</body>
</html>

Answer 1

Instead of trying to control it in your LoginFilter , create a new class that extends com.sun.identity.agents.filter.AmAgentFilter and configure that in your web.xml . You class would look something like this:

public class CustomFilter extends AmAgentFilter {
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        super.init(filterConfig);
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        if (InitListener.isIAMEnabled()) {
            HttpSession session = httpRequest.getSession();
            String userType = (String) session.getAttribute(Constant.USER_TYPE);
            if ("internal".equals(userType)) {
                super.doFilter(servletRequest, servletResponse, filterChain);
            }
        }
        filterChain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {
        super.destroy();
    }
}

The super.doFilter() call will only perform the actions in AmAgentFilter if the criteria in that if-block is met; otherwise, we ignore that filter and move on to the next one in the chain.

You would configure this filter in your web.xml instead of the AmAgentFilter .