lucene/queryparser/src/java/org/apache/lucene/queryparser/flexible/standard/builders/DummyQueryNodeBuilder.java

/*
 * 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.
 */
package org.apache.lucene.queryparser.flexible.standard.builders;

import org.apache.lucene.queryparser.flexible.core.QueryNodeException;
import org.apache.lucene.queryparser.flexible.core.builders.QueryTreeBuilder;
import org.apache.lucene.queryparser.flexible.core.nodes.QueryNode;
import org.apache.lucene.search.TermQuery;

/**
 * This builder does nothing. Commonly used for {@link QueryNode} objects that
 * are built by its parent's builder.
 * 
 * @see StandardQueryBuilder
 * @see QueryTreeBuilder
 */
public class DummyQueryNodeBuilder implements StandardQueryBuilder {

  /**
   * Constructs a {@link DummyQueryNodeBuilder} object.
   */
  public DummyQueryNodeBuilder() {
    // empty constructor
  }

  /**
   * Always return <code>null</code>.
   * 
   * return <code>null</code>
   */
  @Override
  public TermQuery build(QueryNode queryNode) throws QueryNodeException {
    return null;
  }

}