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

Class QueryNodeProcessorImpl

java.lang.Object

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

All Implemented Interfaces:

QueryNodeProcessor

Direct Known Subclasses:

AllowLeadingWildcardProcessor, AnalyzerQueryNodeProcessor, BooleanModifiersQueryNodeProcessor, BooleanSingleChildOptimizationQueryNodeProcessor, BoostQueryNodeProcessor, DefaultPhraseSlopQueryNodeProcessor, FuzzyQueryNodeProcessor, LowercaseExpandedTermsQueryNodeProcessor, MatchAllDocsQueryNodeProcessor, MultiFieldQueryNodeProcessor, MultiTermRewriteMethodProcessor, NoChildOptimizationQueryNodeProcessor, NumericQueryNodeProcessor, NumericRangeQueryNodeProcessor, OpenRangeQueryNodeProcessor, PhraseSlopQueryNodeProcessor, RemoveDeletedQueryNodesProcessor, RemoveEmptyNonLeafQueryNodeProcessor, TermRangeQueryNodeProcessor, WildcardQueryNodeProcessor

public abstract class QueryNodeProcessorImpl
extends Object
implements QueryNodeProcessor

This is a default implementation for the QueryNodeProcessor interface, it's an abstract class, so it should be extended by classes that want to process a QueryNode tree.

This class process QueryNodes from left to right in the tree. While it's walking down the tree, for every node, preProcessNode(QueryNode) is invoked. After a node's children are processed, postProcessNode(QueryNode) is invoked for that node. setChildrenOrder(List) is invoked before postProcessNode(QueryNode) only if the node has at least one child, in setChildrenOrder(List) the implementor might redefine the children order or remove any children from the children list.

Here is an example about how it process the nodes:

      a
     / \
    b   e
   / \
  c   d
 

Here is the order the methods would be invoked for the tree described above:

      preProcessNode( a );
      preProcessNode( b );
      preProcessNode( c );
      postProcessNode( c );
      preProcessNode( d );
      postProcessNode( d );
      setChildrenOrder( bChildrenList );
      postProcessNode( b );
      preProcessNode( e );
      postProcessNode( e );
      setChildrenOrder( aChildrenList );
      postProcessNode( a )
 

See Also:

QueryNodeProcessor

Constructor Summary

Constructors

Constructor	Description
QueryNodeProcessorImpl()
QueryNodeProcessorImpl(QueryConfigHandler queryConfigHandler)

Method Summary

Modifier and Type	Method	Description
QueryConfigHandler	getQueryConfigHandler()	For reference about this method check: QueryNodeProcessor.getQueryConfigHandler().
QueryNode	process(QueryNode queryTree)	Processes a query node tree.
void	setQueryConfigHandler(QueryConfigHandler queryConfigHandler)	For reference about this method check: QueryNodeProcessor.setQueryConfigHandler(QueryConfigHandler).

Methods inherited from class java.lang.Object

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

Constructor Detail

QueryNodeProcessorImpl

public QueryNodeProcessorImpl()

QueryNodeProcessorImpl

public QueryNodeProcessorImpl(QueryConfigHandler queryConfigHandler)

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

Parameters:

queryTree - tree root node

Returns:

the processed query tree

Throws:

QueryNodeException

setQueryConfigHandler

public void setQueryConfigHandler(QueryConfigHandler queryConfigHandler)

For reference about this method check: QueryNodeProcessor.setQueryConfigHandler(QueryConfigHandler).

Specified by:

setQueryConfigHandler in interface QueryNodeProcessor

Parameters:

queryConfigHandler - the query configuration handler to be set.

See Also:

QueryNodeProcessor.getQueryConfigHandler(), QueryConfigHandler

getQueryConfigHandler

public QueryConfigHandler getQueryConfigHandler()

For reference about this method check: QueryNodeProcessor.getQueryConfigHandler().

Specified by:

getQueryConfigHandler in interface QueryNodeProcessor

Returns:

QueryConfigHandler the query configuration handler to be set.

See Also:

QueryNodeProcessor.setQueryConfigHandler(QueryConfigHandler), QueryConfigHandler