--- /dev/null
+package org.apache.lucene.search;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.io.IOException;
+import java.util.Iterator;
+import java.util.Set;
+import java.util.TreeSet;
+
+import org.apache.lucene.index.IndexReader;
+import org.apache.lucene.index.Term;
+import org.apache.lucene.index.TermDocs;
+import org.apache.lucene.util.FixedBitSet;
+
+/**
+ * Constructs a filter for docs matching any of the terms added to this class.
+ * Unlike a RangeFilter this can be used for filtering on multiple terms that are not necessarily in
+ * a sequence. An example might be a collection of primary keys from a database query result or perhaps
+ * a choice of "category" labels picked by the end user. As a filter, this is much faster than the
+ * equivalent query (a BooleanQuery with many "should" TermQueries)
+ *
+ */
+public class TermsFilter extends Filter
+{
+ Set<Term> terms=new TreeSet<Term>();
+
+ /**
+ * Adds a term to the list of acceptable terms
+ * @param term
+ */
+ public void addTerm(Term term)
+ {
+ terms.add(term);
+ }
+
+/* (non-Javadoc)
+ * @see org.apache.lucene.search.Filter#getDocIdSet(org.apache.lucene.index.IndexReader)
+ */
+ @Override
+ public DocIdSet getDocIdSet(IndexReader reader) throws IOException
+ {
+ FixedBitSet result=new FixedBitSet(reader.maxDoc());
+ TermDocs td = reader.termDocs();
+ try
+ {
+ for (Iterator<Term> iter = terms.iterator(); iter.hasNext();)
+ {
+ Term term = iter.next();
+ td.seek(term);
+ while (td.next())
+ {
+ result.set(td.doc());
+ }
+ }
+ }
+ finally
+ {
+ td.close();
+ }
+ return result;
+ }
+
+ @Override
+ public boolean equals(Object obj)
+ {
+ if(this == obj)
+ return true;
+ if((obj == null) || (obj.getClass() != this.getClass()))
+ return false;
+ TermsFilter test = (TermsFilter)obj;
+ return (terms == test.terms ||
+ (terms != null && terms.equals(test.terms)));
+ }
+
+ @Override
+ public int hashCode()
+ {
+ int hash=9;
+ for (Iterator<Term> iter = terms.iterator(); iter.hasNext();)
+ {
+ Term term = iter.next();
+ hash = 31 * hash + term.hashCode();
+ }
+ return hash;
+ }
+
+}