OpenCMIS Server Framework
The OpenCMIS Server Framework provides a server implementation of both CMIS bindings, AtomPub and Web Services, and maps them to Java interfaces. Requests and data from CMIS clients are converted and pushed to a repository connector. The connector translates the CMIS calls into native repository calls.
Repository Connector Development
This is a brief description of the interfaces and classes a repository connector has to extend and implement. For interface details see the OpenCMIS Server Framework SPI JavaDoc.
Framework Entry Point
A repository connector has to extend the AbstractServiceFactory
class. This class manages the objects that implement the CMIS service interface. There is only one active instance of this factory class per servlet context. The class name has to be set in the configuration file /WEB-INF/classes/repository.properties
.
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# set fully qualified class name class=org.repository.ServicesFactory |
The configuration file may contain more key-value pairs. They are passed to the init
method of the AbstractServiceFactory
object when the servlet context starts up.
For each request the getService
method will be called and a CallContext
object will be passed. This CallContext
object contains data about the request, such as the used binding, the repository id, username and password. The getService
method must return an object that implements the CmisService
interface. This object will only be used in this thread. When the object is not needed anymore, the close
method on the object will be called.
It is up to the repository connector how these service objects are created and maintained. It is possible to create such an object for each request or keep an instance per thread in a ThreadLocal or manage service objects in a pool. If you reuse a service object make sure that it doesn't hold any state from previous requests.
Service Interface
The CmisService
interface contains all operations of the CMIS specification and a few more. Most methods are named after the operations described in the CMIS specification. There are a few exceptions to that rule because the AtomPub binding doesn't always allow a one-to-one mapping. Those divergences are explained in the JavaDoc.
The methods take the same parameters as described in the CMIS specification. There are also a few exceptions that are explained in the JavaDoc.
It is recommended to extend the AbstractCmisService
class instead of implementing the CmisService
interface directly. AbstractCmisService
contains several convenience methods and covers all AtomPub specifics in a generic way.
AtomPub Specifics
The AtomPub binding needs more object data than many of the operations return. Therefore a repository connector has to provide ObjectInfo
objects through the getObjectInfo
method. AbstractCmisService
provides a generic implementation of getObjectInfo
. If you don't notice any performance issue with the AtomPub binding, you don't have to bother with ObjectInfo
objects.
If the generic assembly of ObjectInfo
objects raises a problem, a repository connector can build them itself. AbstractCmisService
provides a addObjectInfo
method that takes and manages ObjectInfo
objects. Which objects are required for which operation is documented in the JavaDoc.
Authentication Framework
Authentication information is transported to the service implementation via the CallContext
object. The CallContext
is basically a Map and can contain any kind of data. The OpenCMIS server fills it by default with a username and a password from either HTTP basic authentication for the AtomPub binding or WS-Security (UsernameToken) for the Web Services binding.
Other authentication methods can be plugged in if needed. Here is how this works for the two CMIS bindings.
AtomPub authentication
For the AtomPub binding a new class implementing the interface org.apache.chemistry.opencmis.server.impl.atompub.CallContextHandler
has to be created. It gets the HttpServletRequest
object of the current request and returns key-value pairs that are added to the CallContext
. See the JavaDoc for details.
The new CallContext
handler can be activated by changing the servlet init parameter callContextHandler
in /WEB-INF/web.xml]
.
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<init-param> <param-name>callContextHandler</param-name> <param-value>org.example.opencmis.MyCallContextHandler</param-value> </init-param> |
Web Services authentication
For the Web Services binding a new SOAPHandler
class has to be created and registered in /WEB-INF/sun-jaxws.xml
.
The handleMessage
method should look like this:
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| ||||
public boolean handleMessage(SOAPMessageContext context) { Boolean outboundProperty = (Boolean) context.get(MessageContext.MESSAGE_OUTBOUND_PROPERTY); if (outboundProperty.booleanValue()) { // we are only looking at inbound messages return true; } // do whatever you have to do here String user = ... String secret = ... // set up key-value pairs for the CallContext Map<String, String> callContextMap = new HashMap<String, String>(); callContextMap.put("org.example.opencmis.user", user); callContextMap.put("org.example.opencmis.secret", secret); // add key-value pairs the SOAP message context context.put(AbstractService.CALL_CONTEXT_MAP, callContextMap); context.setScope(AbstractService.CALL_CONTEXT_MAP, Scope.APPLICATION); return true; } |
Repository Connector Deployment
The OpenCMIS build process creates a WAR file in /chemistry-opencmis-server/chemistry-opencmis-server/target
. This WAR file should be used as a template. It can be deployed as it is but doesn't do anything.
In order to use your connector, copy your compiled connector code into this WAR file and overwrite /WEB-INF/classes/repository.properties
.
Have a look at the OpenCMIS FileShare Repository test repository code and pom.xml
. It's a simple example of a repository connector.