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

java.lang.Object
  extended by org.apache.lucene.queryParser.core.processors.QueryNodeProcessorImpl
      extended by 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


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