ptdb.kernel.bl.search

Class SearchResultBuffer

java.lang.Object

java.util.Observable

ptdb.kernel.bl.search.SearchResultBuffer

All Implemented Interfaces:

java.util.Observer, ResultHandler

public class SearchResultBuffer
extends java.util.Observable
implements ResultHandler, java.util.Observer

The buffer for caching the search results from the previous searchers.

This class extends class Observable, to implement the Observer pattern.

It requires the SearchResultListener from the GUI layer to implement the Observer interface, and register in this class to get notified when there are results being added into the buffer.

Since:

Ptolemy II 10.0

Version:

$Id$

Author:

Alek Wang

Pt.AcceptedRating:

red (wenjiaow)

Pt.ProposedRating:

red (wenjiaow)

Constructor Summary

Constructors

Constructor and Description
SearchResultBuffer()

Method Summary

Modifier and Type	Method and Description
java.util.ArrayList<XMLDBModel>	getResults() Get the results stored in the buffer.
void	handleIntermediateResults(java.util.List<XMLDBModel> intermediateResults, ResultHandler resultHandler) Handle the intermediate results found and passed by the other searchers in the searchers chain.
void	handleResults(java.util.ArrayList<XMLDBModel> modelResults) Called by the other searcher to write the searched results to this buffer.
boolean	isSearchCancelled() Check whether the searching process has been canceled by the user.
boolean	isWholeSearchDone() Check whether the all the searchers in the search chain have finished.
void	passErrorModels(java.util.List<XMLDBModel> errorModels) Handle the error models passed by the other searchers.
void	setConnection(DBConnection connection) Set the DB connection for this result handler.
void	update(java.util.Observable observable, java.lang.Object argument) Implement the update method from the Observer interface.
void	wholeSearchDone() Notify the search result buffer that the searching is done.

Methods inherited from class java.util.Observable

addObserver, clearChanged, countObservers, deleteObserver, deleteObservers, hasChanged, notifyObservers, notifyObservers, setChanged

Methods inherited from class java.lang.Object

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

Constructor Detail

SearchResultBuffer

public SearchResultBuffer()

Method Detail

getResults

public java.util.ArrayList<XMLDBModel> getResults()

Get the results stored in the buffer. After the results is read once from this buffer, that set of results will be removed from the buffer. Do not read the same set of results twice.

Returns:

All the searched model results in this buffer.

handleIntermediateResults

public void handleIntermediateResults(java.util.List<XMLDBModel> intermediateResults,
                                      ResultHandler resultHandler)

Handle the intermediate results found and passed by the other searchers in the searchers chain.

The intermediate results are currently stored in a HashMap to distinguish the results passed by different searchers. This class can be extended later to fetch different intermediate searched results.

Specified by:

handleIntermediateResults in interface ResultHandler

Parameters:

intermediateResults - The intermediate results found in the other searchers.

resultHandler - The result handler searcher that finds and passes the intermediate results.

handleResults

public void handleResults(java.util.ArrayList<XMLDBModel> modelResults)

Called by the other searcher to write the searched results to this buffer. If there is some other results that are already stored in the buffer, the new results will appended to the existing results.

When the results are written to the buffer in this method, the buffer will notify its registered observers. The SearchResultListener, which should have registered in this buffer will be called to notify.

Specified by:

handleResults in interface ResultHandler

Parameters:

modelResults - The models results to be stored in this buffer.

isSearchCancelled

public boolean isSearchCancelled()

Check whether the searching process has been canceled by the user.

Specified by:

isSearchCancelled in interface ResultHandler

Returns:

true - The search has been canceled by the user.
false - The search hasn't been canceled.

isWholeSearchDone

public boolean isWholeSearchDone()

Check whether the all the searchers in the search chain have finished.

Returns:

true - the searching is done.
false - the searching is not done yet.

passErrorModels

public void passErrorModels(java.util.List<XMLDBModel> errorModels)

Handle the error models passed by the other searchers.

For now, the passed error models are just stored in the buffer, but this class can be modified later to add more function for handling passed error models.

Specified by:

passErrorModels in interface ResultHandler

Parameters:

errorModels - The passed error models.

setConnection

public void setConnection(DBConnection connection)

Set the DB connection for this result handler.

Specified by:

setConnection in interface ResultHandler

Parameters:

connection - The DBConnection instance to be set in this result handler.

update

public void update(java.util.Observable observable,
                   java.lang.Object argument)

Implement the update method from the Observer interface. This class is assumed to only observe the SearchResultFrame class, so this update() method is only called by the SearchResultFrame to cancel the search. So this method only perform the operations to cancel the search operation.

Specified by:

update in interface java.util.Observer

Parameters:

observable - The object that this SearchResultBuffer is observing. It is assumed that this SearchResultBuffer will only observe the SearchResultFrame window.

argument - The argument passed to this SearcResultBuffer.

wholeSearchDone

public void wholeSearchDone()
                     throws DBConnectionException

Notify the search result buffer that the searching is done.

Specified by:

wholeSearchDone in interface ResultHandler

Throws:

DBConnectionException - Thrown if the DB connection cannot be obtained.