org.apache.lucene.queryparser.flexible.precedence.processors

Class BooleanModifiersQueryNodeProcessor

java.lang.Object

org.apache.lucene.queryparser.flexible.core.processors.QueryNodeProcessorImpl

org.apache.lucene.queryparser.flexible.precedence.processors.BooleanModifiersQueryNodeProcessor

All Implemented Interfaces:

QueryNodeProcessor

public class BooleanModifiersQueryNodeProcessor
extends QueryNodeProcessorImpl

This processor is used to apply the correct ModifierQueryNode to BooleanQueryNodes children.

It walks through the query node tree looking for BooleanQueryNodes. If an AndQueryNode is found, every child, which is not a ModifierQueryNode or the ModifierQueryNode is ModifierQueryNode.Modifier.MOD_NONE, becomes a ModifierQueryNode.Modifier.MOD_REQ. For any other BooleanQueryNode which is not an OrQueryNode, it checks the default operator is StandardQueryConfigHandler.Operator.AND, if it is, the same operation when an AndQueryNode is found is applied to it.

See Also:

StandardQueryConfigHandler.ConfigurationKeys.DEFAULT_OPERATOR, StandardQueryParser.setDefaultOperator(org.apache.lucene.queryparser.flexible.standard.config.StandardQueryConfigHandler.Operator)

Constructor Summary

Constructors

Constructor and Description
BooleanModifiersQueryNodeProcessor()

Method Summary

Modifier and Type	Method and Description
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.
QueryNode	process(QueryNode queryTree) Processes a query node 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, processChildren, setQueryConfigHandler

Methods inherited from class java.lang.Object

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

Constructor Detail

BooleanModifiersQueryNodeProcessor

public BooleanModifiersQueryNodeProcessor()

Method Detail

process

public QueryNode process(QueryNode queryTree)
                  throws QueryNodeException

Description copied from interface: QueryNodeProcessor

Processes a query node tree. It may return the same or another query tree. I should never return null.

Specified by:

process in interface QueryNodeProcessor

Overrides:

process in class QueryNodeProcessorImpl

Parameters:

queryTree - tree root node

Returns:

the processed query tree

Throws:

QueryNodeException

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