org.apache.lucene.search

Class FieldValueFilter

java.lang.Object

org.apache.lucene.search.Filter

org.apache.lucene.search.FieldValueFilter

public class FieldValueFilter
extends Filter

A Filter that accepts all documents that have one or more values in a given field. This Filter request Bits from LeafReader.getDocsWithField(java.lang.String)

Constructor Summary

Constructors

Constructor and Description
FieldValueFilter(String field) Creates a new FieldValueFilter
FieldValueFilter(String field, boolean negate) Creates a new FieldValueFilter

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(Object obj)
String	field() Returns the field this filter is applied on.
DocIdSet	getDocIdSet(LeafReaderContext context, Bits acceptDocs) Creates a DocIdSet enumerating the documents that should be permitted in search results.
int	hashCode()
boolean	negate() Returns true iff this filter is negated, otherwise false
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

FieldValueFilter

public FieldValueFilter(String field)

Creates a new FieldValueFilter

Parameters:

field - the field to filter

FieldValueFilter

public FieldValueFilter(String field,
                boolean negate)

Creates a new FieldValueFilter

Parameters:

field - the field to filter

negate - iff true all documents with no value in the given field are accepted.

Method Detail

field

public String field()

Returns the field this filter is applied on.

Returns:

the field this filter is applied on.

negate

public boolean negate()

Returns true iff this filter is negated, otherwise false

Returns:

true iff this filter is negated, otherwise false

getDocIdSet

public DocIdSet getDocIdSet(LeafReaderContext context,
                   Bits acceptDocs)
                     throws IOException

Description copied from class: Filter

Creates a DocIdSet enumerating the documents that should be permitted in search results. NOTE: null can be returned if no documents are accepted by this Filter.

Note: This method will be called once per segment in the index during searching. The returned DocIdSet must refer to document IDs for that segment, not for the top-level reader.

Specified by:

getDocIdSet in class Filter

Parameters:

context - a LeafReaderContext instance opened on the index currently searched on. Note, it is likely that the provided reader info does not represent the whole underlying index i.e. if the index has more than one segment the given reader only represents a single segment. The provided context is always an atomic context, so you can call LeafReader.fields() on the context's reader, for example.

acceptDocs - Bits that represent the allowable docs to match (typically deleted docs but possibly filtering other documents)

Returns:

a DocIdSet that provides the documents which should be permitted or prohibited in search results. NOTE: null should be returned if the filter doesn't accept any documents otherwise internal optimization might not apply in the case an empty DocIdSet is returned.

Throws:

IOException

hashCode

public int hashCode()

Overrides:

hashCode in class Object

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

toString

public String toString()

Overrides:

toString in class Object