com.sptci.prevayler.query
Class FetchRange<P extends PrevalentObject,S extends PrevalentSystem>

java.lang.Object
  com.sptci.prevayler.query.AbstractQuery<Collection<P>,S>
      com.sptci.prevayler.query.FetchRange<P,S>

All Implemented Interfaces:

Query

public class FetchRange<P extends PrevalentObject,S extends PrevalentSystem>
extends AbstractQuery<Collection<P>,S>

The query used to retrieve prevalent objects of the specified type in the range specified. This is used to retrieve paginated view of the prevalent objects stored in the prevalent system.

Version:

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

Author:

Rakesh Vidyadharan 2008-05-27

See Also:

© Copyright 2008 Sans Pareil Technologies, Inc.

Field Summary

private Class	cls The type of prevalent objects to retrieve.
private long	end The ending index (exclusive) of the range to which to fetch objects.
private long	start The starting index (inclusive) of the range from which to fetch objects.

Constructor Summary

FetchRange(Class cls, long start, long end)
Create a new instance of the query for the specified parameters.

Method Summary

protected Collection<P>

query(S system, Date timestamp) Execute the query on the prevalent system and return the prevalent objects that fall in the specified range.

Methods inherited from class com.sptci.prevayler.query.AbstractQuery

query

Methods inherited from class java.lang.Object

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

Field Detail

cls

private final Class cls

The type of prevalent objects to retrieve.

start

private final long start

The starting index (inclusive) of the range from which to fetch objects.

end

private final long end

The ending index (exclusive) of the range to which to fetch objects.

Constructor Detail

FetchRange

public FetchRange(Class cls,
                  long start,
                  long end)

Create a new instance of the query for the specified parameters.

Parameters:

cls - The cls value to use.

start - The start value to use.

end - The end value to use.

Method Detail

query

protected Collection<P> query(S system,
                              Date timestamp)
                                               throws PrevalentException

Execute the query on the prevalent system and return the prevalent objects that fall in the specified range.

Specified by:

query in class AbstractQuery<Collection<P extends PrevalentObject>,S extends PrevalentSystem>

Parameters:

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

timestamp - The timestamp for the query.

Returns:

The collection of prevalent objects in the specified range. Return an empty collection if no objects are in the range.

Throws:

PrevalentException - If errors are encountered while fetching the required prevalent objects.