CQ & Sling servlets: resourceType

Last time we see how to use Sling servlets with old legacy URL. Today we’ll see how to create Sling Servlets in the Sling-way: using resourceType.

Scenario

We want a component that can be dragged into a parsys. With a form that submit data to a sling servlet. Then the servlet will do the operations required.

Process

Let’s create the component following the CQ guidelines for making it drag-droppable into a parsys (allowedParents): geometrixx/components/test003. The test003.jsp will look like the following:

<%@include file="/libs/foundation/global.jsp"%>
<form name="frm" method="post" action="<c:out value="${resource.path}" />.c">
    <input type="submit" />
</form>

This JSP will answer at a GET http call showing the form. In order to use, create a content page and drag the component into a parsys.

Now it’s time to create the servlet. As usual you’ll have to register it using some felix annotations. The following servlet will be used when posting (HTTP POST) to a resource of type geometrixx/components/test003 with an extension of “c”.

package com.samples.sling;

import java.io.IOException;
import javax.servlet.ServletException;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.servlets.SlingAllMethodsServlet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @scr.component immediate="true" metatype="false"
 * @scr.service interface="javax.servlet.Servlet"
 * @scr.property name="sling.servlet.methods" values.0="POST"
 * @scr.property name="sling.servlet.resourceTypes" values.0="geometrixx/components/test003"
 * @scr.property name="sling.servlet.extensions" values.0="c"
 */

public class ResourceTypePostServlet extends SlingAllMethodsServlet {
   private static final long serialVersionUID = 8795673847499208743L;
   private final static Logger logger = LoggerFactory.getLogger(ResourceTypePostServlet.class);

   @Override
   protected void doPost(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
      logger.debug("ResourceTypePostServlet::doPost()");
      response.setContentType("text/plain");
      response.getOutputStream().print("Hello ResourceTypePostServlet World!");
   }
}

We used the sling.servlet.methods to specify which HTTP method the servlet listen to, the sling.servlet.resourceTypes to specify all the resource types is should listen to and the .extensions if you wish to specify an extension.

Remember that if you specify a sling.servlet.paths, resourceTypes, extensions and selectors will be ignored.

Now build the bundle and refresh the previously created content page (should not necessary actually). If you click on the “submit” button you’ll see the Hello World.

References:

CQ & Sling servlets: old legacy URL

SlingIn this short article (first of a serie I hope) I’ll show you how to create a Sling Servlet in CQ.

Scenario

You are migrating your existing application in CQ a piece at time and it’s time for the Servlets (controllers) part, so for the first stage you’d like to keep the old URLs. Maybe because some other external services are calling you at these coordinates or because you don’t want to enter each jsp and change the forms action.

Ingredients

  • CQ instance running in Author (localhost:4502)
  • CRXDE (let’s ease the game for starting)

Process

Create a new OSGi bundle under geometrixx (or your app). In this create a new class that extends the SlingSafeMethodsServlet.
Then you have to register as a service in the OSGi container. This is done using the Felix annotations as following:

/**
 * @scr.component immediate="true" metatype="false"
 * @scr.service interface="javax.servlet.Servlet"
 * @scr.property name="sling.servlet.methods" values.0="GET"
 * @scr.property name="sling.servlet.paths" values.0="/path/to/my/servlet"
 *                                          values.1="/apps/path/to/my/servlet"
 */

I’ll leave you to the references section of this post for getting deeper into the meaning of each.

At the end your code will look something like the following:

package com.samples.sling;

import java.io.IOException;
import javax.servlet.ServletException;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.servlets.SlingSafeMethodsServlet;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @scr.component immediate="true" metatype="false"
 * @scr.service interface="javax.servlet.Servlet"
 * @scr.property name="sling.servlet.methods" values.0="GET"
 * @scr.property name="sling.servlet.paths" values.0="/path/to/my/servlet"
 *                values.1="/apps/path/to/my/servlet"
 */
public class AbsoluteUrlServlet extends SlingSafeMethodsServlet {
   private static final long serialVersionUID = -1920460619265757059L;
   private static final Logger logger = LoggerFactory.getLogger(AbsoluteUrlServlet.class);

   @Override
   protected void doGet(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServletException, IOException {
      logger.debug("AbsoluteUrlServlet::doGet()");
      response.setContentType("text/plain");
      response.getOutputStream().print("Hello AbsoluteUrlServlet World!");
   }
}

Looking at the sling.servlet.paths annotation we se on which url we are actually mapping the servlet: /path/to/my/servlet and /apps/path/to/my/servlet.

Building the bundle and CRXDE+felix will do the magic of the deployment.

Now if you try to run localhost:4502/apps/path/to/my/servlet you’ll see our beautiful Helloworld, but if you’ll try to access localhost:4502/path/to/my/servlet you’ll get a 404 or a content listing.
This is due to a settings in felix+Sling. Open the felix console at the configuration tab (/system/console/configMgr) and search for Apache Sling Servlet/Script Resolver and Error Handler. Here you’ll have to add “/path/” to the Execution Paths section.

Done done!

References

CQ5 author instance and Apache

Here at a customer site, we have a CQ application deployed into “/” context root (as usual) of weblogic 9.2 alongside other functional web apps. All of this sites behind Apache httpd which serves some html files as well as reverse proxies to weblogic based on some urls.

Generally there’s no problem in this except that in this case, when accessing from apache the “/” it serves its htdocs directory so we are not able to login to cq. When logging into CQ, the login form POSTs to http://admin:admin@<server>/?sling:authRequestLogin=1 which needs to be proxied to CQ’s / instead of Apache’s htdocs. As apache is serving its content, no CQ filter is fired.

If we make the weblogic-handler module to come in action for “/” we loose all the apache content. As well, we cannot move all the apache content into CQ.

So the problem is how do we make Apache to use weblogic handler only for a particular URL and query string? We’ve come to a solution combining both Apache configs and some crx node creation.

First, the apache configs:

<LocationMatch "^/(content|libs|siteadmin|apps|bin|home|etc|welcome|var|tmp|cf|useradmin|damadmin|miscadmin|workflow|tagging|inbox|cqauthurl)">
SetHandler weblogic-handler
</LocationMatch>

This sets all the urls in the LocationMatch to be handled by weblogic-handler to proxy to CQ.

As you may have noticed we are dealing with a /cqauthurl that is not a CQ url. We need to use Content Explorer to create the node /cqauthurl (nt:unstructured). This will avoid a 404.

The add the following rewrite rule in Apache configs; as general or within the location should make no difference:

RewriteRule ^/cqlogin$ /libs/cq/core/content/login.html?resource=/siteadmin [R]
RewriteCond %{QUERY_STRING}  ^sling:authRequestLogin=1$
RewriteRule (.*) /cqauthurl [PT]

The first line will allow the user to bookmark a simple url like http://<server>/cqlogin. When accessing this url there will be a redirect onto the CQ’s Login.

The second and third lines tells apache: when on the query string there’s sling:authRequestLogin=1 then rewrite to /cqauthurl.

This lets the user’s login go through to CQ and caches the basic auth credentials for all paths under http://author-server:port/

CQ Site admin needs to be accessed via http://author-server:port/siteadmin instead of the root context.

weekly links 2010-48

It’s been a long time I’m not posting but just changed job and relocated abroad, so no time for the blog.

SocialAuth – Java Library for seamless authentication for oAuth and OpenID providers

Eclipse Makes Available New Release of Eclipse Virgo

Using «Federated Login for Google Account Users» in your application

Introducing CQ 5.4, an early sneak-peek.

The way we write software these days

Why Java is being used for high-performance computing

Goodbye SOAP – Welcome JSON REST

Being bad to your customers is bad for business

Oracle’s Reply to Google’s Answer with Counterclaims

A Closer Look at JUnit Categories