CQ5: 403 Forbidden occurs when call a Post servlet

Question

Hi I'm using this code to create a Post method for my CQ5 example application.

package com.adobe.cq.sling;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.rmi.ServerException;
import java.util.Dictionary;

import org.apache.felix.scr.annotations.Properties;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.sling.SlingServlet;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.SlingHttpServletResponse;
import org.apache.sling.api.servlets.SlingSafeMethodsServlet;
import org.apache.sling.commons.osgi.OsgiUtil;
import org.apache.sling.jcr.api.SlingRepository;
import org.apache.felix.scr.annotations.Reference;
import org.osgi.service.component.ComponentContext;
import javax.jcr.Session;
import javax.jcr.Node; 
import org.json.simple.JSONObject;
import java.util.UUID;

@SlingServlet(paths="/bin/mySearchServlet", methods = "POST", metatype=true)
public class HandleClaim extends org.apache.sling.api.servlets.SlingAllMethodsServlet {
     private static final long serialVersionUID = 2598426539166789515L;


     @Override
     protected void doPost(SlingHttpServletRequest request, SlingHttpServletResponse response) throws ServerException, IOException {

      try
      {
         //Get the submitted form data that is sent from the
              //CQ web page  
          String id = UUID.randomUUID().toString();
          String firstName = request.getParameter("firstName");
          String lastName = request.getParameter("lastName");
          String address = request.getParameter("address");
          String cat = request.getParameter("cat");
          String state = request.getParameter("state");
          String details = request.getParameter("details");
          String date = request.getParameter("date"); 
          String city = request.getParameter("city"); 

          //Encode the submitted form data to JSON
          JSONObject obj=new JSONObject();
          obj.put("id",id);
          obj.put("firstname",firstName);
          obj.put("lastname",lastName);
          obj.put("address",address);
          obj.put("cat",cat);
          obj.put("state",state);
          obj.put("details",details);
          obj.put("date",date);
          obj.put("city",city);

             //Get the JSON formatted data    
          String jsonData = obj.toJSONString();

             //Return the JSON formatted data
         response.getWriter().write(jsonData);
      }
      catch(Exception e)
      {
          e.printStackTrace();
      }
    }
}

it work ok with a GET request. But for a POST(doPost) request i recevied a message: 403 Forbidden. What i should do to resolve this issue ?

Answer 1

This issue will never happen If you call the method from internal client (for example: jsp file, ajax or Servlets that located in your application). However if you call it from external client (another website or REST client plugin...) CQ security filter will be triggered to prevent your action then return 403 error to remove this please follow these steps:

1/ http://localhost:4502/system/console/configMgr
2/ Search for 'Apache Sling Referrer Filter'
3/ Remove POST method from the filter. Then you can call your POST method anywhere.

Answer 2

As mentioned at http://sling.apache.org/documentation/the-sling-engine/servlets.html, a servlet using the sling.servlet.paths property might be ignored unless its path is included in the Execution Paths (servletresolver.paths) configuration setting of the SlingServletResolver service. You should find that configuration at /system/console/configMgr/org.apache.sling.servlets.resolver.SlingServletResolver .

In your case I suppose the /bin/mySearchServlet path is not included in that configuration parameter and causes CQ to return a 403 status. If that's right you can either add your path there (assuming you understand the security implications) or mount your servlets on one of the paths that's configured there.

Note that it's best to avoid mounting servlet on paths if possible, creating a resource at the desired path is preferred as mentioned on that documentation page.

Answer 3

In addition to the other answers, If you are on AEM 6.1 this issue can also be caused by a CSRF Configuration as explained on this post.

Short answer, check that the POST method is NOT in the filter methods of the CSRF filter config

http://localhost:4502/system/console/configMgr/com.adobe.granite.csrf.impl.CSRFFilter