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package org.apache.lucene.search;
/**
* Copyright 2004 The Apache Software Foundation
*
* Licensed 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.util.BitSet;
import java.util.Date;
import java.io.IOException;
import org.apache.lucene.document.DateField;
import org.apache.lucene.index.Term;
import org.apache.lucene.index.TermDocs;
import org.apache.lucene.index.TermEnum;
import org.apache.lucene.index.IndexReader;
/**
* A Filter that restricts search results to a range of time.
*
* <p>For this to work, documents must have been indexed with a
* {@link DateField}.
*/
public class DateFilter extends Filter {
String field;
String start = DateField.MIN_DATE_STRING();
String end = DateField.MAX_DATE_STRING();
private DateFilter(String f) {
field = f;
}
/**
* Constructs a filter for field <code>f</code> matching dates
* between <code>from</code> and <code>to</code> inclusively.
*/
public DateFilter(String f, Date from, Date to) {
field = f;
start = DateField.dateToString(from);
end = DateField.dateToString(to);
}
/**
* Constructs a filter for field <code>f</code> matching times
* between <code>from</code> and <code>to</code> inclusively.
*/
public DateFilter(String f, long from, long to) {
field = f;
start = DateField.timeToString(from);
end = DateField.timeToString(to);
}
/**
* Constructs a filter for field <code>f</code> matching
* dates on or before before <code>date</code>.
*/
public static DateFilter Before(String field, Date date) {
DateFilter result = new DateFilter(field);
result.end = DateField.dateToString(date);
return result;
}
/**
* Constructs a filter for field <code>f</code> matching times
* on or before <code>time</code>.
*/
public static DateFilter Before(String field, long time) {
DateFilter result = new DateFilter(field);
result.end = DateField.timeToString(time);
return result;
}
/**
* Constructs a filter for field <code>f</code> matching
* dates on or after <code>date</code>.
*/
public static DateFilter After(String field, Date date) {
DateFilter result = new DateFilter(field);
result.start = DateField.dateToString(date);
return result;
}
/**
* Constructs a filter for field <code>f</code> matching
* times on or after <code>time</code>.
*/
public static DateFilter After(String field, long time) {
DateFilter result = new DateFilter(field);
result.start = DateField.timeToString(time);
return result;
}
/**
* Returns a BitSet with true for documents which should be
* permitted in search results, and false for those that should
* not.
*/
public BitSet bits(IndexReader reader) throws IOException {
BitSet bits = new BitSet(reader.maxDoc());
TermEnum enumerator = reader.terms(new Term(field, start));
TermDocs termDocs = reader.termDocs();
if (enumerator.term() == null) {
return bits;
}
try {
Term stop = new Term(field, end);
while (enumerator.term().compareTo(stop) <= 0) {
termDocs.seek(enumerator.term());
while (termDocs.next()) {
bits.set(termDocs.doc());
}
if (!enumerator.next()) {
break;
}
}
} finally {
enumerator.close();
termDocs.close();
}
return bits;
}
public String toString() {
StringBuffer buffer = new StringBuffer();
buffer.append(field);
buffer.append(":");
buffer.append(DateField.stringToDate(start).toString());
buffer.append("-");
buffer.append(DateField.stringToDate(end).toString());
return buffer.toString();
}
}