| /* |
| * 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.spans; |
| |
| import java.util.List; |
| |
| import org.apache.lucene.queryparser.flexible.core.QueryNodeException; |
| import org.apache.lucene.queryparser.flexible.core.config.QueryConfigHandler; |
| import org.apache.lucene.queryparser.flexible.core.nodes.FieldableNode; |
| import org.apache.lucene.queryparser.flexible.core.nodes.QueryNode; |
| import org.apache.lucene.queryparser.flexible.core.processors.QueryNodeProcessorImpl; |
| |
| /** |
| * This processor changes every field name of each {@link FieldableNode} query |
| * node contained in the query tree to the field name defined in the |
| * {@link UniqueFieldAttribute}. So, the {@link UniqueFieldAttribute} must be |
| * defined in the {@link QueryConfigHandler} object set in this processor, |
| * otherwise it throws an exception. |
| * |
| * @see UniqueFieldAttribute |
| */ |
| public class UniqueFieldQueryNodeProcessor extends QueryNodeProcessorImpl { |
| |
| @Override |
| protected QueryNode postProcessNode(QueryNode node) throws QueryNodeException { |
| |
| return node; |
| |
| } |
| |
| @Override |
| protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException { |
| |
| if (node instanceof FieldableNode) { |
| FieldableNode fieldNode = (FieldableNode) node; |
| |
| QueryConfigHandler queryConfig = getQueryConfigHandler(); |
| |
| if (queryConfig == null) { |
| throw new IllegalArgumentException( |
| "A config handler is expected by the processor UniqueFieldQueryNodeProcessor!"); |
| } |
| |
| if (!queryConfig.has(SpansQueryConfigHandler.UNIQUE_FIELD)) { |
| throw new IllegalArgumentException( |
| "UniqueFieldAttribute should be defined in the config handler!"); |
| } |
| |
| String uniqueField = queryConfig.get(SpansQueryConfigHandler.UNIQUE_FIELD); |
| fieldNode.setField(uniqueField); |
| |
| } |
| |
| return node; |
| |
| } |
| |
| @Override |
| protected List<QueryNode> setChildrenOrder(List<QueryNode> children) |
| throws QueryNodeException { |
| |
| return children; |
| |
| } |
| |
| } |