org.apache.lucene.queryParser.standard.processors
Class BooleanSingleChildOptimizationQueryNodeProcessor

java.lang.Object
  org.apache.lucene.queryParser.core.processors.QueryNodeProcessorImpl
      org.apache.lucene.queryParser.standard.processors.BooleanSingleChildOptimizationQueryNodeProcessor

All Implemented Interfaces:

QueryNodeProcessor

public class BooleanSingleChildOptimizationQueryNodeProcessor
extends QueryNodeProcessorImpl

This processor removes every BooleanQueryNode that contains only one child and returns this child. If this child is ModifierQueryNode that was defined by the user. A modifier is not defined by the user when it's a BooleanModifierNode

See Also:

ModifierQueryNode

Constructor Summary

BooleanSingleChildOptimizationQueryNodeProcessor()

Method Summary

protected QueryNode	postProcessNode(QueryNode node) This method is invoked for every node when walking up the tree.
protected QueryNode	preProcessNode(QueryNode node) This method is invoked for every node when walking down the tree.
protected List<QueryNode>	setChildrenOrder(List<QueryNode> children) This method is invoked for every node that has at least on child.

Methods inherited from class org.apache.lucene.queryParser.core.processors.QueryNodeProcessorImpl

getQueryConfigHandler, process, processChildren, setQueryConfigHandler

Methods inherited from class java.lang.Object

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

Constructor Detail

BooleanSingleChildOptimizationQueryNodeProcessor

public BooleanSingleChildOptimizationQueryNodeProcessor()

Method Detail

postProcessNode

protected QueryNode postProcessNode(QueryNode node)
                             throws QueryNodeException

Description copied from class: QueryNodeProcessorImpl

This method is invoked for every node when walking up the tree.

Specified by:

postProcessNode in class QueryNodeProcessorImpl

Parameters:

node - node the query node to be post-processed

Returns:

a query node

Throws:

QueryNodeException - if something goes wrong during the query node processing

preProcessNode

protected QueryNode preProcessNode(QueryNode node)
                            throws QueryNodeException

Description copied from class: QueryNodeProcessorImpl

This method is invoked for every node when walking down the tree.

Specified by:

preProcessNode in class QueryNodeProcessorImpl

Parameters:

node - the query node to be pre-processed

Returns:

a query node

Throws:

QueryNodeException - if something goes wrong during the query node processing

setChildrenOrder

protected List<QueryNode> setChildrenOrder(List<QueryNode> children)
                                    throws QueryNodeException

Description copied from class: QueryNodeProcessorImpl

This method is invoked for every node that has at least on child. It's invoked right before QueryNodeProcessorImpl.postProcessNode(QueryNode) is invoked.

Specified by:

setChildrenOrder in class QueryNodeProcessorImpl

Parameters:

children - the list containing all current node's children

Returns:

a new list containing all children that should be set to the current node

Throws:

QueryNodeException - if something goes wrong during the query node processing