com.sptci.prevayler.query
Class AbstractQuery<T,S extends PrevalentSystem>

java.lang.Object
  com.sptci.prevayler.query.AbstractQuery<T,S>

All Implemented Interfaces:

Query

Direct Known Subclasses:

Count, Fetch, FetchByIndex, FetchByIndices, FetchRange, Search

public abstract class AbstractQuery<T,S extends PrevalentSystem>
extends Object
implements Query

A base class for all simple queries against the prevalent system.

© Copyright 2008 Sans Pareil Technologies, Inc.

Version:

$Id: AbstractQuery.java 22 2008-11-24 19:04:25Z sptrakesh $

Author:

Rakesh Vidyadharan 2008-05-27

Constructor Summary

AbstractQuery()

Method Summary

Object	query(Object prevalentSystem, Date executionTime) Implementation of the interface method.
protected abstract T	query(S system, Date timestamp) Execute the query on the prevalent system and return the results.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

AbstractQuery

public AbstractQuery()

Method Detail

query

public Object query(Object prevalentSystem,
                    Date executionTime)
             throws Exception

Implementation of the interface method. Properly type-casts the object parameter to a PrevalentSystem and hands over to query( PrevalentSystem, Date ).

Specified by:

query in interface Query

Parameters:

prevalentSystem - The prevalent system against which the query is to be performed.

executionTime - The timestamp for the query.

Returns:

The result of executing the query.

Throws:

Exception - If errors are encountered while executing the query.

query

protected abstract T query(S system,
                           Date timestamp)
                    throws Exception

Execute the query on the prevalent system and return the results.

Parameters:

system - The prevalent system that is to be acted upon.

timestamp - The timestamp for the query.

Returns:

The results of the query.

Throws:

Exception - If errors are encountered while executing the query.