|
|
Lucene example source code file (NumericRangeFilterBuilder.java)
This example Lucene source code file (NumericRangeFilterBuilder.java) is included in the DevDaily.com
"Java Source Code
Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.
The Lucene NumericRangeFilterBuilder.java source code
package org.apache.lucene.xmlparser.builders;
/**
* 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 org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.DocIdSet;
import org.apache.lucene.search.Filter;
import org.apache.lucene.search.NumericRangeFilter;
import org.apache.lucene.util.NumericUtils;
import org.apache.lucene.xmlparser.DOMUtils;
import org.apache.lucene.xmlparser.FilterBuilder;
import org.apache.lucene.xmlparser.ParserException;
import org.w3c.dom.Element;
/**
* Creates a {@link NumericRangeFilter}. The table below specifies the required
* attributes and the defaults if optional attributes are omitted. For more
* detail on what each of the attributes actually do, consult the documentation
* for {@link NumericRangeFilter}:
* <table>
* <tr>
* <th>Attribute name
* <th>Values
* <th>Required
* <th>Default
* </tr>
* <tr>
* <td>fieldName |
* <td>String
* <td>Yes
* <td>N/A
* </tr>
* <tr>
* <td>lowerTerm
* <td>Specified by type
* <td>Yes
* <td>N/A
* </tr>
* <tr>
* <td>upperTerm
* <td>Specified by type
* <td>Yes
* <td>N/A
* </tr>
* <tr>
* <td>type
* <td>int, long, float, double
* <td>No
* <td>int
* </tr>
* <tr>
* <td>includeLower
* <td>true, false
* <td>No
* <td>true
* </tr>
* <tr>
* <td>includeUpper
* <td>true, false
* <td>No
* <td>true
* </tr>
* <tr>
* <td>precisionStep
* <td>Integer
* <td>No
* <td>4
* </tr>
* </table>
* <p>
* If an error occurs parsing the supplied <tt>lowerTerm or
* <tt>upperTerm into the numeric type specified by type, then the
* error will be silently ignored and the resulting filter will not match any
* documents.
*/
public class NumericRangeFilterBuilder implements FilterBuilder {
private static final NoMatchFilter NO_MATCH_FILTER = new NoMatchFilter();
private boolean strictMode = false;
/**
* Specifies how this {@link NumericRangeFilterBuilder} will handle errors.
* <p>
* If this is set to true, {@link #getFilter(Element)} will throw a
* {@link ParserException} if it is unable to parse the lowerTerm or upperTerm
* into the appropriate numeric type. If this is set to false, then this
* exception will be silently ignored and the resulting filter will not match
* any documents.
* <p>
* Defaults to false.
*
* @param strictMode
*/
public void setStrictMode(boolean strictMode) {
this.strictMode = strictMode;
}
public Filter getFilter(Element e) throws ParserException {
String field = DOMUtils.getAttributeWithInheritanceOrFail(e, "fieldName");
String lowerTerm = DOMUtils.getAttributeOrFail(e, "lowerTerm");
String upperTerm = DOMUtils.getAttributeOrFail(e, "upperTerm");
boolean lowerInclusive = DOMUtils.getAttribute(e, "includeLower", true);
boolean upperInclusive = DOMUtils.getAttribute(e, "includeUpper", true);
int precisionStep = DOMUtils.getAttribute(e, "precisionStep", NumericUtils.PRECISION_STEP_DEFAULT);
String type = DOMUtils.getAttribute(e, "type", "int");
try {
Filter filter;
if (type.equalsIgnoreCase("int")) {
filter = NumericRangeFilter.newIntRange(field, precisionStep, Integer
.valueOf(lowerTerm), Integer.valueOf(upperTerm), lowerInclusive,
upperInclusive);
} else if (type.equalsIgnoreCase("long")) {
filter = NumericRangeFilter.newLongRange(field, precisionStep, Long
.valueOf(lowerTerm), Long.valueOf(upperTerm), lowerInclusive,
upperInclusive);
} else if (type.equalsIgnoreCase("double")) {
filter = NumericRangeFilter.newDoubleRange(field, precisionStep, Double
.valueOf(lowerTerm), Double.valueOf(upperTerm), lowerInclusive,
upperInclusive);
} else if (type.equalsIgnoreCase("float")) {
filter = NumericRangeFilter.newFloatRange(field, precisionStep, Float
.valueOf(lowerTerm), Float.valueOf(upperTerm), lowerInclusive,
upperInclusive);
} else {
throw new ParserException(
"type attribute must be one of: [long, int, double, float]");
}
return filter;
} catch (NumberFormatException nfe) {
if (strictMode) {
throw new ParserException(
"Could not parse lowerTerm or upperTerm into a number", nfe);
}
return NO_MATCH_FILTER;
}
}
static class NoMatchFilter extends Filter {
private static final long serialVersionUID = 1L;
@Override
public DocIdSet getDocIdSet(IndexReader reader) throws IOException {
return null;
}
}
}
Other Lucene examples (source code examples)
Here is a short list of links related to this Lucene NumericRangeFilterBuilder.java source code file:
The search page
Other Lucene source code examples at this package level
Click here to learn more about this project
