com.antelmann.util
Interface QueryMechanism

All Known Subinterfaces:

OfficeDocument

All Known Implementing Classes:

AbstractDatabase, AbstractOfficeDocument, GDB, Logger, OOCalc, OODraw, OOWriter, OpenGeoDB, SQLDatabase, SQLFactoryDatabase

public interface QueryMechanism

provides a generic way to query an object for flexible functionality

Since:

21.10.2009, 17:38:52

Author:

Holger Antelmann

Method Summary

<T> T

query(Class<T> requiredReturnType, Object context) queries the instance for an object of the given type that is appropriate for the given context.

Method Detail

query

<T> T query(Class<T> requiredReturnType,
            Object context)
        throws IOException,
               IllegalArgumentException

queries the instance for an object of the given type that is appropriate for the given context.

Type Parameters:

T - the required return type

Parameters:

requiredReturnType - specifies the return type that is needed for this operation; if Object.class is given, any returned object is admissible

context - provides a context parameter for which the desired instance is to be returned. Often (if no other meaningful context is required or applicable), it makes sense to pass a reference to the calling object source; null may also be allowed

Returns:

an instance of the required return type that matches the given context; null may be returned if no instance is available for the given context

Throws:

IOException - if any resource could not be acquired to fulfill the given query

IllegalArgumentException - if either parameter is generally not acceptable by the implementation