OpenCMIS Client Bindings

The OpenCMIS client bindings layer hides the CMIS AtomPub and Web Services bindings and provides an interface that is very similar to the CMIS domain model . The services, operations, parameters, and structures are named after the CMIS domain model and behave as described in the CMIS specification.

The primary objective of the client bindings layer is to be complete, covering all CMIS operations and extension points. The result is a somewhat clunky interface. The OpenCMIS Client API sits on top of the provider layer and exposes a nicer and simpler to use interface. It is the better choice for most applications.

A connection to a CMIS repository is represented by a CmisBinding object. Such an object can be created by the CmisBindingFactory. The factory provides three main methods, one for each binding and third one for a local connection (same JVM), that require binding specific connection information. The created CmisBinding object exposes a binding agnostic interface.

CmisBinding is the entry point to the CMIS services and a few utility operations. It contains a transparent cache for repository infos and type definitions. The object is serializable, although dehydrating can be expensive. CmisBinding is thread-safe.

The get*Service() methods provide access to the CMIS services. Some service operations take provider layer specific objects. These objects should be created with the BindingsObjectFactory. This factory can be obtained through the getObjectFactory() method of the CmisBinding object.

Please refer to the OpenCMIS Commons JavaDoc and OpenCMIS Client Binding JavaDoc for more details on the interfaces.

Sample Code

Creating an AtomPub binding instance

The AtomPub binding requires the URL of the CMIS service document. HTTP basic authentication is enabled by default and a username and a password have to be provided.

    Map<String, String> parameters = new HashMap<String, String>();
    
    parameters.put(SessionParameter.USER, user);
    parameters.put(SessionParameter.PASSWORD, password);
    
    parameters.put(SessionParameter.ATOMPUB_URL, url); // service document URL
    
    CmisBindingFactory factory = CmisBindingFactory.newInstance();
    CmisBinding binding = factory.createCmisAtomPubBinding(parameters);

Creating a Web Services binding instance

The Web Services binding requires a WSDL URL for each CMIS service. This might the same the URL for all services. WS-Security (UsernameToken) is enabled by default and a username and a password have to be provided.

    Map<String, String> parameters = new HashMap<String, String>();
    
    parameters.put(SessionParameter.USER, username);
    parameters.put(SessionParameter.PASSWORD, password);
    
    parameters.put(SessionParameter.WEBSERVICES_REPOSITORY_SERVICE, repositoryServiceWsdlUrl);
    parameters.put(SessionParameter.WEBSERVICES_NAVIGATION_SERVICE, navigationServiceWsdlUrl);
    parameters.put(SessionParameter.WEBSERVICES_OBJECT_SERVICE, objectServiceWsdlUrl);
    parameters.put(SessionParameter.WEBSERVICES_VERSIONING_SERVICE, versioningServiceWsdlUrl);
    parameters.put(SessionParameter.WEBSERVICES_DISCOVERY_SERVICE, discoveryServiceWsdlUrl);
    parameters.put(SessionParameter.WEBSERVICES_RELATIONSHIP_SERVICE, relationshipServiceWsdlUrl);
    parameters.put(SessionParameter.WEBSERVICES_MULTIFILING_SERVICE, multiFilingServiceWsdlUrl);
    parameters.put(SessionParameter.WEBSERVICES_POLICY_SERVICE, policyServiceWsdlUrl);
    parameters.put(SessionParameter.WEBSERVICES_ACL_SERVICE, aclServiceWsdlUrl);
    
    CmisBindingFactory factory = CmisBindingFactory.newInstance();
    CmisBinding binding = factory.createCmisWebServicesBinding(parameters);

Creating a Local binding instance

The Local binding connects to an OpenCMIS server in the same JVM. The server factory class name has to be supplied.

    Map<String, String> parameters = new HashMap<String, String>();
    
    parameters.put(SessionParameter.USER, user);
    parameters.put(SessionParameter.PASSWORD, password);
    
    parameters.put(SessionParameter.LOCAL_FACTORY, factoryClassName);
    
    CmisBindingFactory factory = CmisBindingFactory.newInstance();
    CmisBinding binding = factory.createCmisLocalBinding(parameters);

Getting an Object

The following snippet gets the name of the object "myObject" in repository "myRepository". The parameters of getObject() can be found in the CMIS specification.

    CmisBinding binding = ...
    
    ObjectData myObject = binding.getObjectService().getObject("myRepository", "myObject",
       "*", true, IncludeRelationships.BOTH, "cmis:none", true, true, null);
    
    PropertiesData properties = myObject.getProperties();
    PropertyData<String> nameProperty = properties.getProperties().get(PropertyIds.NAME);
    String name = nameProperty.getFirstValue();

Custom Authentication Provider

OpenCMIS supports HTTP basic authentication for the AtomPub binding and WS-Security (UsernameToken) for the Web Services binding out of the box. Other authentication methods can be added by implementing a custom authentication provider.

Such a provider must extend org.apache.chemistry.opencmis.client.provider.spi.AbstractAuthenticationProvider and overwrite the methods getHTTPHeaders and getSOAPHeaders. See JavaDoc for details.

The session parameter SessionParameter.AUTHENTICATION_PROVIDER_CLASS must be set to the fully qualified class name in order to active the authentication provider before the session is created.

    Map<String, String> parameters = new HashMap<String, String>();
    
    parameters.put(SessionParameter.AUTHENTICATION_PROVIDER_CLASS, "org.example.opencmis.MyAuthenticationProvider");
    parameters.put("org.example.opencmis.user", "cmisuser"); // MyAuthenticationProvider can get and evaluate this
    parameters.put("org.example.opencmis.secret", "b3BlbmNtaXMgdXNlcg==");
    
    parameters.put(SessionParameter.ATOMPUB_URL, url); // service document URL
    
    CmisBindingFactory factory = CmisBindingFactory.newInstance();
    CmisBinding provider = factory.createCmisAtomPubBinding(parameters);