Query Service
This service provides a general object query mechanism for distributed objects. With this service, collections of objects can be searched to generate subcollections, or subsets of objects within a collection can be deleted or updated through a query. The facilities defined in the query service can be mapped to, but aren’t limited to, persistent storage facilities, such as relational or object databases.
Collections of objects are represented by
Collection
objects, which are created using a
CollectionFactory
. Iterate through a
Collection
of objects using an
Iterator
. QueryEvaluator
objects are used to issue a Query
against a
given Collection
. The result of evaluating a
Query
can be any type, but typically it is a
Collection
of some kind. A
QueryManager
is a type of
QueryEvaluator
that allows you to create
queries.
Get Java Enterprise in a Nutshell, Second Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.