SharePoint 2010 is the first SharePoint with a CMIS adapter.  SharePoint 2010 offers a Web Part to request data from other CMIS servers (e.g. Alfresco and Documentum), and a CMIS producer to offer data to CMIS clients (e.g. Apache Chemistry).

Theoretically this means you can write ECM applications targeting SP 2010, Alfresco, and Documentum using only Chemistry (or some other CMIS application), the same as you can write database applications using only JDBC (and the vendor’s JDBC driver).  How well does it work in practice?

Actually, it seems to work pretty well, especially if your application needs can be expressed using the operations supported by CMIS… to some extent CMIS is a lowest common denominator.  The vendor’s specific tools (SharePoint Web Services, Alfresco Explorer and Share, Documentum DFC / DFS) certainly expose much more of the vendor’s unique functionality.  CMIS supports repository, navigation, object, versioning, multifiling, ACL, policy, discovery, and relationship services, via WSDL and REST bindings.

The CMIS standard defines the above services, and also defines bindings for WSDL, and REST (using the Atom protocol).  Apache Chemistry provides a unified API, such that you specify WSDL or REST when you connect to the repository, and then use the same Chemistry API either way.  Chemistry translates your API calls into the appropriate WSDL or REST requests.

For my project, I wanted to use the REST binding, since REST requests tend to be less verbose than WSDL, hence sending less traffic over the wire.  Also I have more experience with REST, since my project is using Spring MVC to publish REST services.

So we tried connecting to SP2010 using Chemistry’s REST bindings.  This was no trouble, as soon as we figured out the right URL to use (something like this: https://<sp2010_url>/_vti_bin/cmis/rest/<list_or_library_guid>?getRepositoryInfo).  Chemistry’s cookbook page was a big help.  Then we tried querying the repository, listing folders, listing folder contents, creating files, and retrieving files.  Everything worked great!  CMIS looked really awesome!

Then we tried checking out a file.  Wham!  We ran into a brick wall here.  SP2010 always returned an HTTP 400 “bad request”, no matter what we tried.  I traced the REST request Chemistry sent to SP2010, and used the excellent Firefox REST Client to send different versions of that request; no matter what, even when I sent invalid XML, I always got the same “bad request” response.

Time to work with Microsoft Support.  They reproduced the error, and are still working on the issue.  However, my support contact tried checking out over WSDL, and it worked fine!  I tried it myself; after jumping over a few hurdles to use Chemistry against SP2010 via WSDL, it worked fine!  So for now, we are stuck using the more-verbose WSDL protocol.  My MS support contact is still working with the REST support though.

As for the hurdles, Chemistry’s cookbook page came to the rescue again; the main issue is you have to download the WSDL from the SP2010 site yourself, and give Chemistry a file-based URL to the downloaded WSDL.  As far as I can tell, you can’t point Chemistry straight to SP2010’s WSDL; I always get a “401 Unauthorized” error.  It might be possible to use a normal HTTP client to download the WSDL locally, then point Chemistry to the dynamically-downloaded WSDL; I haven’t gotten that far yet.

I did make one change to Chemistry’s recipe; the cookbook page says to use Chemistry’s NTLM authentication module.  As far as I can tell, this requires the app server running your Chemistry-based application to run as a Windows domain user known to the SP2010 server.  But I want the app server to run on any Tomcat-supported OS.  Happily, it turns out you can use Chemistry’s standard authentication provider, and just provide a username and password like normal… obviously you would want to run such a connection over HTTPS!

Below is the code snippet I used to verify I could check out from SP2010 using CMIS (specifically Apache Chemistry) over WSDL:

import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.chemistry.opencmis.client.api.Document;
import org.apache.chemistry.opencmis.client.api.ObjectId;
import org.apache.chemistry.opencmis.client.api.Repository;
import org.apache.chemistry.opencmis.client.api.Session;
import org.apache.chemistry.opencmis.client.api.SessionFactory;
import org.apache.chemistry.opencmis.client.bindings.CmisBindingFactory;
import org.apache.chemistry.opencmis.client.runtime.SessionFactoryImpl;
import org.apache.chemistry.opencmis.commons.SessionParameter;
import org.apache.chemistry.opencmis.commons.enums.BindingType;
import org.junit.Test;

/**
*
* @author millerd
*/
public class SharePointWSDLTest
{

@Test
public void connectViaWsdl() throws Exception
{
String cwd = System.getProperty(“user.dir”);
System.out.println(“Working dir: ” + cwd);
// Default factory implementation of client runtime.
SessionFactory sessionFactory = SessionFactoryImpl.newInstance();
Map parameter = new HashMap();

// User credentials.
parameter.put(SessionParameter.USER, “some-domain\\some-user-account”);
parameter.put(SessionParameter.PASSWORD, “some-password”);

// getting the wsdl via http doesn’t work – 401 Unauthorized.
//String wsdl = “https://some-host/_vti_bin/cmissoapwsdl.aspx?wsdl”;

// relative file-based URL works fine so long as you give it the
// right relative path… ie. you have to know what the current
// working directory is.
String wsdl = “file:target/classes/acmv2-sharepoint.wsdl”;
// Connection settings.
parameter.put(SessionParameter.BINDING_TYPE, BindingType.WEBSERVICES.value());
parameter.put(SessionParameter.WEBSERVICES_ACL_SERVICE, wsdl);
parameter.put(SessionParameter.WEBSERVICES_DISCOVERY_SERVICE, wsdl);
parameter.put(SessionParameter.WEBSERVICES_MULTIFILING_SERVICE, wsdl);
parameter.put(SessionParameter.WEBSERVICES_NAVIGATION_SERVICE, wsdl);
parameter.put(SessionParameter.WEBSERVICES_OBJECT_SERVICE, wsdl);
parameter.put(SessionParameter.WEBSERVICES_POLICY_SERVICE, wsdl);
parameter.put(SessionParameter.WEBSERVICES_RELATIONSHIP_SERVICE, wsdl);
parameter.put(SessionParameter.WEBSERVICES_REPOSITORY_SERVICE, wsdl);
parameter.put(SessionParameter.WEBSERVICES_VERSIONING_SERVICE, wsdl);

parameter.put(SessionParameter.AUTHENTICATION_PROVIDER_CLASS, CmisBindingFactory.STANDARD_AUTHENTICATION_PROVIDER);

// Create session.
Session session = null;

// This supposes only one repository is available at the URL.
List repositories = sessionFactory.getRepositories(parameter);
for ( Repository rep : repositories )
{
System.out.println(“Rep name: ” + rep.getName() + “; id: ” + rep.getId());
if ( “Unapproved Files”.equals(rep.getName()) )
{
session = rep.createSession();
Document doc = (Document) session.getObjectByPath(“/2011/05/03/10/31/19/log4j_103124.properties”);
System.out.println(“Doc ID: ” + ( doc == null ? ” *NOT FOUND* ” : doc.getId()));
if ( doc != null )
{
ObjectId co = doc.checkOut();
System.out.println(“Checked out doc ID: ” + co.getId());
}
}
}
Repository soleRepository = sessionFactory.getRepositories(parameter).get(0);
session = soleRepository.createSession();

}
}

 

Stay tuned for my post CMIS, Sharepoint 2010 and File Check-ins