org.apache.lucene.queryParser.core.builders
Class QueryTreeBuilder

java.lang.Object
  extended by org.apache.lucene.queryParser.core.builders.QueryTreeBuilder
All Implemented Interfaces:
QueryBuilder
Direct Known Subclasses:
StandardQueryTreeBuilder

public class QueryTreeBuilder
extends Object
implements QueryBuilder

This class should be used when there is a builder for each type of node. The type of node may be defined in 2 different ways: - by the field name, when the node implements the FieldableNode interface - by its class, it keeps checking the class and all the interfaces and classes this class implements/extends until it finds a builder for that class/interface This class always check if there is a builder for the field name before it checks for the node class. So, field name builders have precedence over class builders. When a builder is found for a node, it's called and the node is passed to the builder. If the returned built object is not null, it's tagged on the node using the tag QUERY_TREE_BUILDER_TAGID. The children are usually built before the parent node. However, if a builder associated to a node is an instance of QueryTreeBuilder, the node is delegated to this builder and it's responsible to build the node and its children.

See Also:
QueryBuilder

Field Summary
static String QUERY_TREE_BUILDER_TAGID
          This tag is used to tag the nodes in a query tree with the built objects produced from their own associated builder.
 
Constructor Summary
QueryTreeBuilder()
          QueryTreeBuilder constructor.
 
Method Summary
 Object build(QueryNode queryNode)
          Builds some kind of object from a query tree.
 void setBuilder(CharSequence fieldName, QueryBuilder builder)
          Deprecated. use setBuilder(String, QueryBuilder) instead
 void setBuilder(Class<? extends QueryNode> queryNodeClass, QueryBuilder builder)
          Associates a class with a builder
 void setBuilder(String fieldName, QueryBuilder builder)
          Associates a field name with a builder.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

QUERY_TREE_BUILDER_TAGID

public static final String QUERY_TREE_BUILDER_TAGID
This tag is used to tag the nodes in a query tree with the built objects produced from their own associated builder.

Constructor Detail

QueryTreeBuilder

public QueryTreeBuilder()
QueryTreeBuilder constructor.

Method Detail

setBuilder

public void setBuilder(String fieldName,
                       QueryBuilder builder)
Associates a field name with a builder.

Parameters:
fieldName - the field name
builder - the builder to be associated

setBuilder

@Deprecated
public void setBuilder(CharSequence fieldName,
                                  QueryBuilder builder)
Deprecated. use setBuilder(String, QueryBuilder) instead

Associates a field name with a builder.

Parameters:
fieldName - the field name
builder - the builder to be associated

setBuilder

public void setBuilder(Class<? extends QueryNode> queryNodeClass,
                       QueryBuilder builder)
Associates a class with a builder

Parameters:
queryNodeClass - the class
builder - the builder to be associated

build

public Object build(QueryNode queryNode)
             throws QueryNodeException
Builds some kind of object from a query tree. Each node in the query tree is built using an specific builder associated to it.

Specified by:
build in interface QueryBuilder
Parameters:
queryNode - the query tree root node
Returns:
the built object
Throws:
QueryNodeException - if some node builder throws a QueryNodeException or if there is a node which had no builder associated to it


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