Lucene example source code file (TermRangeFilter.java)

This example Lucene source code file (TermRangeFilter.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.

Java - Lucene tags/keywords

collator, collator, less, more, multitermquerywrapperfilter, string, string, termrangefilter, termrangefilter, termrangequery, termrangequery, text

The Lucene TermRangeFilter.java source code

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.text.Collator;

/**
 * A Filter that restricts search results to a range of term
 * values in a given field.
 *
 * <p>This filter matches the documents looking for terms that fall into the
 * supplied range according to {@link
 * String#compareTo(String)}, unless a <code>Collator is provided. It is not intended
 * for numerical ranges; use {@link NumericRangeFilter} instead.
 *
 * <p>If you construct a large number of range filters with different ranges but on the 
 * same field, {@link FieldCacheRangeFilter} may have significantly better performance. 
 * @since 2.9
 */
public class TermRangeFilter extends MultiTermQueryWrapperFilter<TermRangeQuery> {
    
  /**
   * @param fieldName The field this range applies to
   * @param lowerTerm The lower bound on this range
   * @param upperTerm The upper bound on this range
   * @param includeLower Does this range include the lower bound?
   * @param includeUpper Does this range include the upper bound?
   * @throws IllegalArgumentException if both terms are null or if
   *  lowerTerm is null and includeLower is true (similar for upperTerm
   *  and includeUpper)
   */
  public TermRangeFilter(String fieldName, String lowerTerm, String upperTerm,
                     boolean includeLower, boolean includeUpper) {
      super(new TermRangeQuery(fieldName, lowerTerm, upperTerm, includeLower, includeUpper));
  }

  /**
   * <strong>WARNING: Using this constructor and supplying a non-null
   * value in the <code>collator parameter will cause every single 
   * index Term in the Field referenced by lowerTerm and/or upperTerm to be
   * examined.  Depending on the number of index Terms in this Field, the 
   * operation could be very slow.
   *
   * @param lowerTerm The lower bound on this range
   * @param upperTerm The upper bound on this range
   * @param includeLower Does this range include the lower bound?
   * @param includeUpper Does this range include the upper bound?
   * @param collator The collator to use when determining range inclusion; set
   *  to null to use Unicode code point ordering instead of collation.
   * @throws IllegalArgumentException if both terms are null or if
   *  lowerTerm is null and includeLower is true (similar for upperTerm
   *  and includeUpper)
   */
  public TermRangeFilter(String fieldName, String lowerTerm, String upperTerm,
                     boolean includeLower, boolean includeUpper,
                     Collator collator) {
      super(new TermRangeQuery(fieldName, lowerTerm, upperTerm, includeLower, includeUpper, collator));
  }

  /**
   * Constructs a filter for field <code>fieldName matching
   * less than or equal to <code>upperTerm.
   */
  public static TermRangeFilter Less(String fieldName, String upperTerm) {
      return new TermRangeFilter(fieldName, null, upperTerm, false, true);
  }

  /**
   * Constructs a filter for field <code>fieldName matching
   * greater than or equal to <code>lowerTerm.
   */
  public static TermRangeFilter More(String fieldName, String lowerTerm) {
      return new TermRangeFilter(fieldName, lowerTerm, null, true, false);
  }

  /** Returns the field name for this filter */
  public String getField() { return query.getField(); }
  
  /** Returns the lower value of this range filter */
  public String getLowerTerm() { return query.getLowerTerm(); }

  /** Returns the upper value of this range filter */
  public String getUpperTerm() { return query.getUpperTerm(); }
  
  /** Returns <code>true if the lower endpoint is inclusive */
  public boolean includesLower() { return query.includesLower(); }
  
  /** Returns <code>true if the upper endpoint is inclusive */
  public boolean includesUpper() { return query.includesUpper(); }

  /** Returns the collator used to determine range inclusion, if any. */
  public Collator getCollator() { return query.getCollator(); }
}