1 package org.apache.lucene.queryParser.spans;
4 * Licensed to the Apache Software Foundation (ASF) under one or more
5 * contributor license agreements. See the NOTICE file distributed with
6 * this work for additional information regarding copyright ownership.
7 * The ASF licenses this file to You under the Apache License, Version 2.0
8 * (the "License"); you may not use this file except in compliance with
9 * the License. You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
20 import java.util.List;
22 import org.apache.lucene.queryParser.core.QueryNodeException;
23 import org.apache.lucene.queryParser.core.config.QueryConfigHandler;
24 import org.apache.lucene.queryParser.core.nodes.FieldableNode;
25 import org.apache.lucene.queryParser.core.nodes.QueryNode;
26 import org.apache.lucene.queryParser.core.processors.QueryNodeProcessorImpl;
29 * This processor changes every field name of each {@link FieldableNode} query
30 * node contained in the query tree to the field name defined in the
31 * {@link UniqueFieldAttribute}. So, the {@link UniqueFieldAttribute} must be
32 * defined in the {@link QueryConfigHandler} object set in this processor,
33 * otherwise it throws an exception.<br/>
36 * @see UniqueFieldAttribute
38 public class UniqueFieldQueryNodeProcessor extends QueryNodeProcessorImpl {
41 protected QueryNode postProcessNode(QueryNode node) throws QueryNodeException {
48 protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException {
50 if (node instanceof FieldableNode) {
51 FieldableNode fieldNode = (FieldableNode) node;
53 QueryConfigHandler queryConfig = getQueryConfigHandler();
55 if (queryConfig == null) {
56 throw new IllegalArgumentException(
57 "A config handler is expected by the processor UniqueFieldQueryNodeProcessor!");
60 if (!queryConfig.has(SpansQueryConfigHandler.UNIQUE_FIELD)) {
61 throw new IllegalArgumentException(
62 "UniqueFieldAttribute should be defined in the config handler!");
65 String uniqueField = queryConfig.get(SpansQueryConfigHandler.UNIQUE_FIELD);
66 fieldNode.setField(uniqueField);
75 protected List<QueryNode> setChildrenOrder(List<QueryNode> children)
76 throws QueryNodeException {