org.eclipse.emf.cdo.view
Interface CDOView

All Superinterfaces:

CDOCommonView, org.eclipse.net4j.util.collection.Closeable, org.eclipse.net4j.util.event.INotifier, org.eclipse.net4j.util.options.IOptionsContainer

All Known Subinterfaces:

CDOAudit, CDOTransaction, InternalCDOTransaction, InternalCDOView

public interface CDOView
extends CDOCommonView, org.eclipse.net4j.util.event.INotifier, org.eclipse.net4j.util.options.IOptionsContainer

A read-only view to the current (i.e. latest) state of the object graph in the repository of the underlying session.

Objects that are accessed through this view are unchangeable for the client. Each attempt to call a mutator on one of these objects or one of their reference collections will result in a ReadOnlyException being thrown immediately.

A view is opened through API of the underlying session like this:

   CDOSession session = ...
   CDOView view = session.openView();
   ...
 

CDOView instances must not be accessed through concurrent client threads.

Since a CDOObject, in a non-TRANSIENT state, is only meaningful in combination with its dedicated view they must also not be accessed through concurrent client threads. Please note that at arbitrary times an arbitrary number of framework background threads are allowed to use and modify a CDOview and its CDOObjects. Whenever you are iterating over a number of CDOObjects and need to ensure that they are not modified by the framework at the same time it is strongly recommended to acquire the view lock and protect your code appropriately.

Since:

2.0

Nested Class Summary

static interface

CDOView.Options

Nested classes/interfaces inherited from interface org.eclipse.emf.cdo.common.CDOCommonView

CDOCommonView.Type

Nested classes/interfaces inherited from interface org.eclipse.net4j.util.event.INotifier

org.eclipse.net4j.util.event.INotifier.Introspection

Field Summary

Fields inherited from interface org.eclipse.emf.cdo.common.CDOCommonView

UNSPECIFIED_DATE

Method Summary

CDOQuery	createQuery(java.lang.String language, java.lang.String queryString)
java.util.concurrent.locks.ReentrantLock	getLock() Returns a reentrant lock that can be used to prevent the framework from writing to any object in this view (as it is caused, for example, by passive updates).
CDOObject	getObject(CDOID id) Returns the object for the given CDOID.
CDOObject	getObject(CDOID id, boolean loadOnDemand) Returns the object for the given CDOID.
<T extends org.eclipse.emf.ecore.EObject> T	getObject(T objectFromDifferentView) Takes an object from a (possibly) different view and contextifies it for the usage with this view.
CDOResource	getResource(java.lang.String path) Same as getResource(String, true).
CDOResource	getResource(java.lang.String path, boolean loadOnDemand)
CDOResourceNode	getResourceNode(java.lang.String path) Returns the resource node with the given path, or null if no such resource node exists.
org.eclipse.emf.ecore.resource.ResourceSet	getResourceSet() Returns the resource set this view is associated with.
CDOResource	getRootResource() Returns the root resource of the repository.
CDOSession	getSession() Returns the session this view was opened by.
org.eclipse.emf.ecore.resource.URIHandler	getURIHandler() Deprecated. This API is provisional and subject to change or removal.
CDOViewSet	getViewSet() Returns the view set this view is associated with.
boolean	hasConflict() Returns always false.
boolean	hasResource(java.lang.String path) Returns true if a resource with the given path exists in the repository, false.
boolean	isDirty() Returns always false.
boolean	isObjectRegistered(CDOID id) Returns true if an object with the given id is currently registered in this view, false otherwise.
void	lockObjects(java.util.Collection<? extends CDOObject> objects, org.eclipse.net4j.util.concurrent.RWLockManager.LockType lockType, long timeout) Locks the given objects.
CDOView.Options	options()
java.util.List<CDOResourceNode>	queryResources(CDOResourceFolder folder, java.lang.String name, boolean exactMatch) Returns a list of the resources in the given folder with a name equal to or starting with the value of the name parameter.
org.eclipse.net4j.util.collection.CloseableIterator<CDOResourceNode>	queryResourcesAsync(CDOResourceFolder folder, java.lang.String name, boolean exactMatch) Returns an iterator over the resources in the given folder with a name equal to or starting with the value of the name parameter.
int	reload(CDOObject... objects) Reloads the given objects from the repository.
void	unlockObjects() Unlocks all locked objects of this view.
void	unlockObjects(java.util.Collection<? extends CDOObject> objects, org.eclipse.net4j.util.concurrent.RWLockManager.LockType lockType) Unlocks the given locked objects of this view.

Methods inherited from interface org.eclipse.emf.cdo.common.CDOCommonView

getTimeStamp, getViewID, getViewType

Methods inherited from interface org.eclipse.net4j.util.collection.Closeable

close, isClosed

Methods inherited from interface org.eclipse.net4j.util.event.INotifier

addListener, removeListener

Method Detail

getSession

CDOSession getSession()

Returns the session this view was opened by.

Specified by:

getSession in interface CDOCommonView

Returns:

The session this view was opened by, or null if this view is closed.

See Also:

Closeable.close(), Closeable.isClosed(), CDOSession.openView(), CDOSession.openView(ResourceSet), CDOSession.openAudit(long), CDOSession.openAudit(ResourceSet, long), CDOSession.openTransaction(), CDOSession.openTransaction(ResourceSet)

getViewSet

CDOViewSet getViewSet()

Returns the view set this view is associated with.

Returns:

The view set this view is associated with, never null.

See Also:

CDOViewSet.getViews()

getResourceSet

org.eclipse.emf.ecore.resource.ResourceSet getResourceSet()

Returns the resource set this view is associated with.

Same as calling getViewSet().getResourceSet().

See Also:

CDOViewSet.getResourceSet()

getURIHandler

@Deprecated
org.eclipse.emf.ecore.resource.URIHandler getURIHandler()

Deprecated. This API is provisional and subject to change or removal.

getLock

java.util.concurrent.locks.ReentrantLock getLock()

Returns a reentrant lock that can be used to prevent the framework from writing to any object in this view (as it is caused, for example, by passive updates).

Acquiring this lock provides a means to safely iterate over multiple model elements without being affected by unanticipated remote updates, like in the following example:

    CDOResource resource = view.getResource("/orders/order-4711");
    PurchaseOrder order = (PurchaseOrder)resource.getContents().get(0);
    ReentrantLock lock = view.getLock();
    if (!lock.tryLock(5L, TimeUnit.SECONDS))
    {
      throw new TimeoutException();
    }
    
    try
    {
      float sum = 0;
      for (OrderDetail detail : order.getOrderDetails())
      {
        sum += detail.getPrice();
      }
      
      System.out.println("Sum: " + sum);
    }
    finally
    {
      lock.unlock();
    }
  }
 

Note that this method really just returns the lock instance but does not acquire the lock! The above example acquires the lock with a timeout that expires after five seconds.

isDirty

boolean isDirty()

Returns always false.

This method has a special implementation in CDOTransaction as well.

See Also:

CDOTransaction.isDirty()

hasConflict

boolean hasConflict()

Returns always false.

This method has a special implementation in CDOTransaction as well.

See Also:

CDOTransaction.hasConflict()

hasResource

boolean hasResource(java.lang.String path)

Returns true if a resource with the given path exists in the repository, false.

See Also:

getResource(String, boolean)

getResource

CDOResource getResource(java.lang.String path,
                        boolean loadOnDemand)

See Also:

ResourceSet.getResource(URI, boolean)

getResource

CDOResource getResource(java.lang.String path)

Same as getResource(String, true).

See Also:

ResourceSet.getResource(URI, boolean)

getResourceNode

CDOResourceNode getResourceNode(java.lang.String path)

Returns the resource node with the given path, or null if no such resource node exists.

getRootResource

CDOResource getRootResource()

Returns the root resource of the repository.

The root resource is a special resource with only CDOResourceNodes in its contents list. You can use it as the main entry into the new resource and folder structure.

queryResources

java.util.List<CDOResourceNode> queryResources(CDOResourceFolder folder,
                                               java.lang.String name,
                                               boolean exactMatch)

Returns a list of the resources in the given folder with a name equal to or starting with the value of the name parameter.

Parameters:

folder - The folder to search in, or null for top level resource nodes.

name - the name or prefix of the resource nodes to return.

exactMatch - true if the complete name of the resource must match, false if only a common prefix of the name must match.

queryResourcesAsync

org.eclipse.net4j.util.collection.CloseableIterator<CDOResourceNode> queryResourcesAsync(CDOResourceFolder folder,
                                                                                         java.lang.String name,
                                                                                         boolean exactMatch)

Returns an iterator over the resources in the given folder with a name equal to or starting with the value of the name parameter. The underlying query will be executed asynchronously.

Parameters:

folder - The folder to search in, or null for top level resource nodes.

name - the name or prefix of the resource nodes to return.

exactMatch - true if the complete name of the resource must match, false if only a common prefix of the name must match.

getObject

CDOObject getObject(CDOID id,
                    boolean loadOnDemand)

Returns the object for the given CDOID.

Parameters:

loadOnDemand - whether to create and load the object, if it doesn't already exist.

Returns:

the object resolved by the CDOID if the id is not null, or null if there isn't one and loadOnDemand is false.

getObject

CDOObject getObject(CDOID id)

Returns the object for the given CDOID.

Same as getObject(id, true).

See Also:

getObject(CDOID, boolean)

getObject

<T extends org.eclipse.emf.ecore.EObject> T getObject(T objectFromDifferentView)

Takes an object from a (possibly) different view and contextifies it for the usage with this view.

• If the given object is contained in this view it is returned unmodified.
• If the given object can not be cast to CDOObject it is returned unmodified.
• If the view of the given object is contained in a different session an IllegalArgumentException is thrown.
• If null is passed null is returned.

isObjectRegistered

boolean isObjectRegistered(CDOID id)

Returns true if an object with the given id is currently registered in this view, false otherwise.

reload

int reload(CDOObject... objects)

Reloads the given objects from the repository.

lockObjects

void lockObjects(java.util.Collection<? extends CDOObject> objects,
                 org.eclipse.net4j.util.concurrent.RWLockManager.LockType lockType,
                 long timeout)
                 throws java.lang.InterruptedException

Locks the given objects. Once the objects are locked, they will not be changed remotely or go in conflict state.

Throws:

java.lang.InterruptedException

unlockObjects

void unlockObjects(java.util.Collection<? extends CDOObject> objects,
                   org.eclipse.net4j.util.concurrent.RWLockManager.LockType lockType)

Unlocks the given locked objects of this view.

unlockObjects

void unlockObjects()

Unlocks all locked objects of this view.

Since:

2.0

createQuery

CDOQuery createQuery(java.lang.String language,
                     java.lang.String queryString)

Since:

2.0

options

CDOView.Options options()

Specified by:

options in interface org.eclipse.net4j.util.options.IOptionsContainer

Since:

2.0