org.apache.lucene.search.suggest
Class DocumentValueSourceDictionary

java.lang.Object
  org.apache.lucene.search.suggest.DocumentDictionary
      org.apache.lucene.search.suggest.DocumentValueSourceDictionary

All Implemented Interfaces:

Dictionary

public class DocumentValueSourceDictionary
extends DocumentDictionary

Dictionary with terms and optionally payload information taken from stored fields in a Lucene index. Similar to DocumentDictionary, except it obtains the weight of the terms in a document based on a ValueSource.

NOTE:

• The term and (optionally) payload fields have to be stored
• if the term or (optionally) payload fields supplied do not have a value for a document, then the document is rejected by the dictionary

In practice the ValueSource will likely be obtained using the lucene expression module. The following example shows how to create a ValueSource from a simple addition of two fields: Expression expression = JavascriptCompiler.compile("f1 + f2"); SimpleBindings bindings = new SimpleBindings(); bindings.add(new SortField("f1", SortField.Type.LONG)); bindings.add(new SortField("f2", SortField.Type.LONG)); ValueSource valueSource = expression.getValueSource(bindings);

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.lucene.search.suggest.DocumentDictionary

DocumentDictionary.DocumentInputIterator

Field Summary

Fields inherited from class org.apache.lucene.search.suggest.DocumentDictionary

payloadField, reader

Constructor Summary

DocumentValueSourceDictionary(IndexReader reader, String field, ValueSource weightsValueSource)
Creates a new dictionary with the contents of the fields named field for the terms and uses the weightsValueSource supplied to determine the score.

DocumentValueSourceDictionary(IndexReader reader, String field, ValueSource weightsValueSource, String payload)
Creates a new dictionary with the contents of the fields named field for the terms, payloadField for the corresponding payloads and uses the weightsValueSource supplied to determine the score.

Method Summary

InputIterator

getEntryIterator() Returns an iterator over all the entries

Methods inherited from class java.lang.Object

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

Constructor Detail

DocumentValueSourceDictionary

public DocumentValueSourceDictionary(IndexReader reader,
                                     String field,
                                     ValueSource weightsValueSource,
                                     String payload)

Creates a new dictionary with the contents of the fields named field for the terms, payloadField for the corresponding payloads and uses the weightsValueSource supplied to determine the score.

DocumentValueSourceDictionary

public DocumentValueSourceDictionary(IndexReader reader,
                                     String field,
                                     ValueSource weightsValueSource)

Creates a new dictionary with the contents of the fields named field for the terms and uses the weightsValueSource supplied to determine the score.

Method Detail

getEntryIterator

public InputIterator getEntryIterator()
                               throws IOException

Description copied from interface: Dictionary

Returns an iterator over all the entries

Specified by:

getEntryIterator in interface Dictionary

Overrides:

getEntryIterator in class DocumentDictionary

Returns:

Iterator

Throws:

IOException