org.apache.lucene.search
Class BooleanFilter

java.lang.Object
  org.apache.lucene.search.Filter
      org.apache.lucene.search.BooleanFilter

All Implemented Interfaces:

Serializable, Iterable<FilterClause>

public class BooleanFilter
extends Filter
implements Iterable<FilterClause>

A container Filter that allows Boolean composition of Filters. Filters are allocated into one of three logical constructs; SHOULD, MUST NOT, MUST The results Filter BitSet is constructed as follows: SHOULD Filters are OR'd together The resulting Filter is NOT'd with the NOT Filters The resulting Filter is AND'd with the MUST Filters

See Also:

Serialized Form

Constructor Summary

BooleanFilter()

Method Summary

void	add(Filter filter, BooleanClause.Occur occur)
void	add(FilterClause filterClause) Adds a new FilterClause to the Boolean Filter container
List<FilterClause>	clauses() Returns the list of clauses
boolean	equals(Object obj)
DocIdSet	getDocIdSet(IndexReader reader) Returns the a DocIdSetIterator representing the Boolean composition of the filters that have been added.
int	hashCode()
Iterator<FilterClause>	iterator() Returns an iterator on the clauses in this query.
String	toString() Prints a user-readable version of this Filter.

Methods inherited from class java.lang.Object

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

Constructor Detail

BooleanFilter

public BooleanFilter()

Method Detail

getDocIdSet

public DocIdSet getDocIdSet(IndexReader reader)
                     throws IOException

Returns the a DocIdSetIterator representing the Boolean composition of the filters that have been added.

Specified by:

getDocIdSet in class Filter

Parameters:

reader - a IndexReader instance opened on the index currently searched on. Note, it is likely that the provided reader 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.

Returns:

a DocIdSet that provides the documents which should be permitted or prohibited in search results. NOTE: null can be returned if no documents will be accepted by this Filter.

Throws:

IOException

See Also:

DocIdBitSet

add

public void add(FilterClause filterClause)

Adds a new FilterClause to the Boolean Filter container

Parameters:

filterClause - A FilterClause object containing a Filter and an Occur parameter

add

public final void add(Filter filter,
                      BooleanClause.Occur occur)

clauses

public List<FilterClause> clauses()

Returns the list of clauses

iterator

public final Iterator<FilterClause> iterator()

Returns an iterator on the clauses in this query. It implements the Iterable interface to make it possible to do:

for (FilterClause clause : booleanFilter) {}

Specified by:

iterator in interface Iterable<FilterClause>

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Prints a user-readable version of this Filter.

Overrides:

toString in class Object