org.apache.lucene.queryparser.flexible.core.processors
Class NoChildOptimizationQueryNodeProcessor

java.lang.Object
  org.apache.lucene.queryparser.flexible.core.processors.QueryNodeProcessorImpl
      org.apache.lucene.queryparser.flexible.core.processors.NoChildOptimizationQueryNodeProcessor

All Implemented Interfaces:

QueryNodeProcessor

public class NoChildOptimizationQueryNodeProcessor
extends QueryNodeProcessorImpl

A NoChildOptimizationQueryNodeProcessor removes every BooleanQueryNode, BoostQueryNode, TokenizedPhraseQueryNode or ModifierQueryNode that do not have a valid children.

Example: When the children of these nodes are removed for any reason then the nodes may become invalid.

Constructor Summary

NoChildOptimizationQueryNodeProcessor()

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.flexible.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

NoChildOptimizationQueryNodeProcessor

public NoChildOptimizationQueryNodeProcessor()

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