no.sesat.search.mode.command
Class AbstractSearchCommand

java.lang.Object
  no.sesat.search.mode.command.AbstractSearchCommand

All Implemented Interfaces:

Serializable, Callable<ResultList<ResultItem>>, SearchCommand

Direct Known Subclasses:

AbstractWebServiceSearchCommand, AbstractXmlSearchCommand, MathExpressionSearchCommand, PropertiesCommand, SolrSearchCommand, StaticSearchCommand, StockSearchCommand

public abstract class AbstractSearchCommand
extends Object
implements SearchCommand, Serializable

The base abstraction for Search Commands providing a large framework for commands to run against.

While the SearchCommand interface defines basic execution behavour this abstraction defines:

• delegation of the call method to the execute method so to provide a default implementation for handling cancellations, thread renaming during execution, and avoidance of execution on blank queries,
• assigned queryBuilder and filterBuilder to express the query and filter as the index's requires,
• delegation to the appropriate query to use (sometimes not the user's query),
• handling and control of the query transformations as defined in the commands config,
• handling and control of the result handlers as defined in the commands config,
• helper methods, beyond the query transformers, for filter (and advanced-filter) construction,
• assigned displayableQueryBuilder for constructing a user presentable version of the transformed query, that in turn can be parsed again by sesat's query parser to return the same query.

This command undertook a large refactoring in 2.18 to clean up internal concerns. See the specification http://sesat.no/new-design-proposal-for-searchcommand-and-abstractsearchcommand.html

Version:

$Id: AbstractSearchCommand.java 7225 2009-04-09 00:32:20Z ssmiweve $

See Also:

Serialized Form

Nested Class Summary

protected static class	AbstractSearchCommand.QueryBuilderFactory
protected static class	AbstractSearchCommand.ReconstructedQuery see createQuery(string)

Nested classes/interfaces inherited from interface no.sesat.search.mode.command.SearchCommand

SearchCommand.Context

Field Summary

protected boolean	completed
protected SearchCommand.Context	context The context to work against.
protected DataModel	datamodel
protected Map<String,StringDataObject>	datamodelParameters
protected static Logger	DUMP
protected String	untransformedQuery

Constructor Summary

AbstractSearchCommand(SearchCommand.Context cxt)
Default constructor.

Method Summary

protected void	addFilterString(String filter) Makes presumption that filter is in format "field:value".
ResultList<ResultItem>	call() Called by thread executor
protected QueryBuilder	constructQueryBuilder(SearchCommand.Context cxt, QueryBuilder.Context queryBuilderContext) Construct from scratch, and return the query builder to use.
protected AbstractSearchCommand.ReconstructedQuery	createQuery(String queryString) Uses QueryParser to create a new Query with all evaluation enabled.
protected AbstractSearchCommand.ReconstructedQuery	createQuery(String queryString, boolean evaluationEnabled) Uses QueryParser to create a new Query with the option to disable evaluation.
protected String	escape(String word) Escape the word (whether it requires escaping or not).
abstract ResultList<ResultItem>	execute()
protected int	getCurrentOffset(int i) Deprecated. instead use getOffset() + i
protected TokenEvaluationEngine	getEngine() Use this always instead of context.getTokenEvaluationEngine() because the command could be running off a different query string.
protected String	getFieldFilter(LeafClause clause) Returns null when no field exists.
protected String	getFilter()
protected FilterBuilder	getFilterBuilder()
protected int	getOffset() Returns the offset applicable to this command.
protected String	getParameter(String paramName) Returns parameter value.
Query	getQuery() Use this always instead of datamodel.getQuery().getQuery() because the command could be running off a different query string.
protected QueryBuilder	getQueryBuilder()
protected String	getQueryRepresentation()
protected Collection<String>	getReservedWords()
protected int	getResultsToReturn()
BaseSearchConfiguration	getSearchConfiguration() Returns the configuration associated with this search command.
protected ResultList<ResultItem>	getSearchResult(String id, DataModel datamodel) Get the results from another search command waiting if neccessary.
protected String	getSingleParameter(String paramName) Deprecated. use getParameter(string) instead
String	getTransformedQuery() Returns the query as it is after the query transformers and command specific query builder have been applied to it.
protected String	getTransformedQuerySesamSyntax() Returns the query as it is after the query transformers have been applied to it.
protected Map<Clause,String>	getTransformedTerms()
protected String	getUserSortBy() Returns the userSortBy applicable to this command and request.
boolean	handleCancellation() Handles cancelling the command.
protected void	initialiseTransformedTerms(Query query) Set (or reset) the transformed terms back to the state before any queryTransformers were run.
boolean	isCancelled() Has the command been cancelled.
boolean	isPaginated() Can this command provide paginated results.
boolean	isUserSortable() Can this command be sorted differently at user's requst.
protected ResultList<ResultItem>	performExecution() Handles the execution process.
protected void	performQueryTransformation()
protected void	performResultHandling(ResultList<ResultItem> result) Perform (delegating out to) all registered result handlers for this command.
protected void	setTransformedQuerySesamSyntax(String sesamSyntax)
protected void	statisticsInfo(String msg)
String	toString()
protected void	updateTransformedQuerySesamSyntax()
protected void	visitXorClause(no.sesat.commons.visitor.Visitor visitor, XorClause clause)

Methods inherited from class java.lang.Object

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

Field Detail

DUMP

protected static final Logger DUMP

context

protected final transient SearchCommand.Context context

The context to work against.

untransformedQuery

protected final String untransformedQuery

datamodel

protected final transient DataModel datamodel

datamodelParameters

protected final transient Map<String,StringDataObject> datamodelParameters

completed

protected volatile boolean completed

Constructor Detail

AbstractSearchCommand

public AbstractSearchCommand(SearchCommand.Context cxt)

Default constructor. Only constructor.

Parameters:

cxt - The context to execute in.

Method Detail

initialiseTransformedTerms

protected final void initialiseTransformedTerms(Query query)

Set (or reset) the transformed terms back to the state before any queryTransformers were run.

Parameters:

query - the query that the transformedTerms map will be constructed from. This should match getQuery()

execute

public abstract ResultList<ResultItem> execute()

getQuery

public Query getQuery()

Use this always instead of datamodel.getQuery().getQuery() because the command could be running off a different query string.

Returns:

getTransformedQuery

public String getTransformedQuery()

Returns the query as it is after the query transformers and command specific query builder have been applied to it.

Returns:

The transformed query.

toString

public String toString()

Overrides:

toString in class Object

getSearchConfiguration

public BaseSearchConfiguration getSearchConfiguration()

Description copied from interface: SearchCommand

Returns the configuration associated with this search command. Typically delegates to the context provided.

Specified by:

getSearchConfiguration in interface SearchCommand

Returns:

The search configuration.

call

public ResultList<ResultItem> call()

Called by thread executor

Specified by:

call in interface Callable<ResultList<ResultItem>>

Specified by:

call in interface SearchCommand

Returns:

handleCancellation

public boolean handleCancellation()

Handles cancelling the command. Inserts an "-1" result list. And does the result handling on it. Returns true if cancellation action was taken.

Specified by:

handleCancellation in interface SearchCommand

Returns:

if cleaning was actually performed

isCancelled

public boolean isCancelled()

Has the command been cancelled. Calling this method only makes sense once the call() method has been.

Specified by:

isCancelled in interface SearchCommand

Returns:

true if cancelled.

constructQueryBuilder

protected QueryBuilder constructQueryBuilder(SearchCommand.Context cxt,
                                             QueryBuilder.Context queryBuilderContext)

Construct from scratch, and return the query builder to use. Default implementation returns the query builder that is configured from the BaseSearchConfiguration.
This method is intended to be overridden, but it called from the constructor. So it is important the overrides do not reference "this", or any other fields as they will likely not be initialised yet.

Parameters:

cxt - search command's context

queryBuilderContext - the query builder context

Returns:

getReservedWords

protected Collection<String> getReservedWords()

visitXorClause

protected void visitXorClause(no.sesat.commons.visitor.Visitor visitor,
                              XorClause clause)

Parameters:

visitor -

clause -

getSearchResult

protected final ResultList<ResultItem> getSearchResult(String id,
                                                       DataModel datamodel)
                                                throws InterruptedException

Get the results from another search command waiting if neccessary.

Parameters:

id -

datamodel -

Returns:

Throws:

InterruptedException

performQueryTransformation

protected void performQueryTransformation()

performExecution

protected final ResultList<ResultItem> performExecution()

Handles the execution process. Will determine whether to call execute() and wrap it with timing info.

Returns:

performResultHandling

protected final void performResultHandling(ResultList<ResultItem> result)

Perform (delegating out to) all registered result handlers for this command. Also performs some hardcoded result handling, eg DataModelResultHandler.

Parameters:

result -

getCurrentOffset

protected int getCurrentOffset(int i)

Deprecated. instead use getOffset() + i

Returns the offset in the result set. If paging is enabled for the current search configuration the offset to the current page will be added to the parameter.

Parameters:

i - the current offset.

Returns:

i plus the offset of the current page.

getOffset

protected int getOffset()

Returns the offset applicable to this command. Zero if the command has no "offset" navigator configured, the value of the offset parameter otherwise.

Returns:

the offset.

isPaginated

public boolean isPaginated()

Description copied from interface: SearchCommand

Can this command provide paginated results.

Specified by:

isPaginated in interface SearchCommand

Returns:

true if results can be paginated.

getUserSortBy

protected String getUserSortBy()

Returns the userSortBy applicable to this command and request. Null if the command has no "sort" navigator configured, the value of the user's userSortBy parameter. This method does not return any command configuration's sort-by attribute (as some subclasses have).

Returns:

the userSortBy. returns null when false == isUserSortable().

isUserSortable

public boolean isUserSortable()

Description copied from interface: SearchCommand

Can this command be sorted differently at user's requst.

Specified by:

isUserSortable in interface SearchCommand

Returns:

true if user sorting is applicable.

getParameter

protected String getParameter(String paramName)

Returns parameter value. Changed since 2.16.1 so that only request parameters are searched.

Parameters:

paramName - the name of the parameter to look for.

Returns:

the parameter value, unescaped, or null if parameter does not exist.

getQueryBuilder

protected QueryBuilder getQueryBuilder()

getQueryRepresentation

protected String getQueryRepresentation()

getFilterBuilder

protected FilterBuilder getFilterBuilder()

getFilter

protected String getFilter()

Returns:

getTransformedTerms

protected final Map<Clause,String> getTransformedTerms()

getSingleParameter

protected final String getSingleParameter(String paramName)

Deprecated. use getParameter(string) instead

Get a string parameter (first if array exists).

Parameters:

paramName - parameter name

Returns:

null when array is null

getEngine

protected TokenEvaluationEngine getEngine()

Use this always instead of context.getTokenEvaluationEngine() because the command could be running off a different query string.

Returns:

createQuery

protected final AbstractSearchCommand.ReconstructedQuery createQuery(String queryString)

Uses QueryParser to create a new Query with all evaluation enabled. XXX Very expensive method to call! Consider disabling evaluation.

Parameters:

queryString - the new query string to parse.

Returns:

newly constructed Query.

createQuery

protected final AbstractSearchCommand.ReconstructedQuery createQuery(String queryString,
                                                                     boolean evaluationEnabled)

Uses QueryParser to create a new Query with the option to disable evaluation. XXX Very expensive method to call! It helps to disable evaluation.

Parameters:

queryString - the new query string to parse.

evaluationEnabled - whether to enable evaluation. if false the DeadTokenEvaluationEngineImpl is used.

Returns:

newly constructed Query.

escape

protected String escape(String word)

Escape the word (whether it requires escaping or not). Default escaping for strings is to enclose in quotes, ie to phrase the word. Default escaping for the ':' character is "\\:". Override this to match back-end (index) specific escaping.

Parameters:

word - The term to escape

Returns:

The escaped version of term.

getFieldFilter

protected final String getFieldFilter(LeafClause clause)

Returns null when no field exists.

Parameters:

clause -

Returns:

statisticsInfo

protected final void statisticsInfo(String msg)

getTransformedQuerySesamSyntax

protected String getTransformedQuerySesamSyntax()

Returns the query as it is after the query transformers have been applied to it. It is normalised.

Returns:

updateTransformedQuerySesamSyntax

protected void updateTransformedQuerySesamSyntax()

setTransformedQuerySesamSyntax

protected void setTransformedQuerySesamSyntax(String sesamSyntax)

addFilterString

protected void addFilterString(String filter)

Makes presumption that filter is in format "field:value". Must be overridden if QueryTransformers return filters in an alternative format.

Parameters:

filter -

getResultsToReturn

protected int getResultsToReturn()

Returns: