db4o

ObjectContainer.Get Method 

Query-By-Example interface to retrieve objects.

ObjectSet Get(
   object template
);

Parameters

template
object to be used as an example to find all matching objects.

Return Value

ObjectSet containing all found objects.

Remarks

Query-By-Example interface to retrieve objects.

Get()
creates an ObjectSet containing all objects in the
ObjectContainer
that match the passed template object.

Calling
Get(NULL)
returns all objects stored in the
ObjectContainer
.


Query Evaluation
All non-null members of the template object are compared against all stored objects of the same class. Primitive type members are ignored if they are 0 or false respectively.

Arrays and all supported
Collection
classes are evaluated for containment. Differences in
length/Size()
are ignored.

Consult the documentation of the Configuration package to configure class-specific behaviour.


Returned Objects
The objects returned in the ObjectSet are instantiated and activated to the preconfigured depth of 5. The activationDepth may be configured globally or individually for classes .

db4o keeps track of all instantiatied objects. Queries will return references to these objects instead of instantiating them a second time.

Objects newly activated by
Get()
can respond to the callback method objectOnActivate .

See Also

ObjectContainer Interface | com.db4o Namespace | activationDepth | Using callbacks