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In OpenCMIS the Session is a semi-generic context-like object (PersistentSessionImpl). It Eventually, there will be two Session implementations. In the persistent model (almost) all changes are immediately passed to the repository. In the transient model all changes are cached until save() is called on the Session object. A Session can be "connected" using parameters to instantiate internally a low-level provider (CmisProvider). The provider holds configuration parameters that enable it to create a low-level SPI through a CmisSpiFactory. Through the SPI you can get to the various SPI *Service implementations.

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• OpenCMIS
  No global registration. A JNDI-based method or dependency injection is suggested but not implemented.

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• OpenCMIS

  Code Block
  Map<String, String> params = ...; // URL, user, password Session session = sessionFactory.createSession(parameters);

Internal layer hierarchy (OpenCMIS)

(All classes and interfaces in bold are for public use. Everything else belongs to the internal machinery.)

• Session
  Main interface of the client API.

• SessionFactory
  Interface of the session factory class.

• SessionFactoryImpl
  Factory class that creates Session objects from a given configuration.

• PersistentSessionImpl
  Implementation of the Session interface that follows the persistent model. Should be created with SessionFactoryImpl.

• TransientSessionImpl (does not exist, yet)
  Implementation of the Session interface that follows the transient model. Should be created with SessionFactoryImpl.

• CmisProviderHelper
  Internal helper class that creates a CmisProvider object. It contains code that is shared by PersistentSessionImpl and TransientSessionImpl. It shouldn't be used by anybody else.

• CmisProvider
  The low-level client interface.

• CmisProviderImpl
  Implementation of the low-level client interface.

• CmisProviderFactory
  Factory class for CmisProvider objects. Although CmisProviderImpl can be instantiated directly, this factory sets some reasonable defaults and does a sanity check on the configuration. It is recommended to use this factory to create a CmisProvider object.

• CmisSpi
  Interface of the binding implementations. This interface is only interesting for binding developers. Applications use the CmisProvider or Session interfaces that hide the binding.

• CmisAtomPubSpi
  AtomPub binding implementation.

• CmisWebServicesSpi
  Web Services binding implementation.

From an application point of view it easy to use:

• If you want to use the client API, create a Session object with SessionFactoryImpl and don't bother about the rest.
• If you want to use the low-level provider API, create a CmisProvider object with CmisProviderFactory and don't bother about the rest.

High-level APIs

From a connection/session you can get the root folder and express high-level operations

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• OpenCMIS
  The base interface is CmisObject. It flushes property changes on updateProperties().

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• OpenCMIS
  FileableCmisObject: , Folder, Document, Relationship, Policy. Relationship

Paging

• Chemistry
  ListPage: a page
  = List + getHasMoreItems + getNumItems
  Implemented by SimpleListPage. This is a data transfert object.

• OpenCMIS
  PagingList: a list of pages which are themselves lists
  = Iterable<List> + getNumItems + getMaxItemsPerPage + size + get(page)
  AbstractPagingList is the base class. This is an active object that can fetch new pages by implementing a fetchPage() method that returns a FetchResult (which is equivalent to Chemistry's ListPage). It also has a LRU cache for pages which is disabled by default.

Provider APIs

This is called "SPI" in Chemistry, and "Provider" in OpenCMIS.

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• OpenCMIS
  From a provider you get the various CMIS services as different interfaces (RepositoryService, ObjectService, NavigationService, etc.) using getters. The interfaces and classes are generic and mimick the JAXB generated onesreflect the CMIS schema.

High-level vs low-level vs implementation

• Chemistry
  The high-level and SPI interfaces are mutualized (ex: org.apache.chemistry.RepositoryInfo).
  Florian> For some objects there are different interfaces on these two levels. For example, the step from ObjectEntry to CMISObject is comparable to OpenCMIS' step from the provider API to the client API.
  Florian> JAXB objects will be necessary for Web Services, similar to OpenCMIS.

• OpenCMIS
  For the same concept OpenCMIS manipulates three different interfaces and their implementations:
  • the one in the high-level client API (ex: org.apache.opencmis.client.api.repository.RepositoryInfo, convenient access to data),
  • the one in the provider (ex: org.apache.opencmis.commons.provider.RepositoryInfoData, access to all extension points),
  • the one from JAXB (CmisRepositoryInfoType).

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• OpenCMIS
  A default OperationContext on the session is used to specify these call parameters. A variant of the high-level methods taking an explicit OperationContext is also available. Furthermore, OperationContext controls the caching behavior of the objects retrieved by the call. In the provider interfaces everything is explicit, following JAXBthe CMIS specification.

Object data

The base object contains information about one object: properties, allowable actions, relationships, renditions, etc.

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• OpenCMIS
  ObjectData is the basic class.
  To provide it context, it is used by delegation is more complex constructions: ObjectInFolderData, ObjectInFolderContainer, ObjectInFolderList, ObjectParentData, ObjectList, etc. thus mimicking JAXBreflect the CMIS schema and allow access to all extension points.

Various enums

Relationship direction:

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