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

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

All Implemented Interfaces:

QueryNodeProcessor

public class AllowLeadingWildcardProcessor
extends QueryNodeProcessorImpl

This processor verifies if StandardQueryConfigHandler.ConfigurationKeys.ALLOW_LEADING_WILDCARD is defined in the QueryConfigHandler. If it is and leading wildcard is not allowed, it looks for every WildcardQueryNode contained in the query node tree and throws an exception if any of them has a leading wildcard ('*' or '?').

See Also:

StandardQueryConfigHandler.ConfigurationKeys.ALLOW_LEADING_WILDCARD

Constructor Summary

AllowLeadingWildcardProcessor()

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.
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.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

AllowLeadingWildcardProcessor

public AllowLeadingWildcardProcessor()

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