| /* |
| * 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.processors; |
| |
| import java.util.ArrayList; |
| 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.BooleanQueryNode; |
| import org.apache.lucene.queryparser.flexible.core.nodes.FieldableNode; |
| import org.apache.lucene.queryparser.flexible.core.nodes.GroupQueryNode; |
| import org.apache.lucene.queryparser.flexible.core.nodes.OrQueryNode; |
| import org.apache.lucene.queryparser.flexible.core.nodes.QueryNode; |
| import org.apache.lucene.queryparser.flexible.core.processors.QueryNodeProcessorImpl; |
| import org.apache.lucene.queryparser.flexible.standard.config.StandardQueryConfigHandler.ConfigurationKeys; |
| |
| /** |
| * This processor is used to expand terms so the query looks for the same term |
| * in different fields. It also boosts a query based on its field. <br> |
| * <br> |
| * This processor looks for every {@link FieldableNode} contained in the query |
| * node tree. If a {@link FieldableNode} is found, it checks if there is a |
| * {@link ConfigurationKeys#MULTI_FIELDS} defined in the {@link QueryConfigHandler}. If |
| * there is, the {@link FieldableNode} is cloned N times and the clones are |
| * added to a {@link BooleanQueryNode} together with the original node. N is |
| * defined by the number of fields that it will be expanded to. The |
| * {@link BooleanQueryNode} is returned. |
| * |
| * @see ConfigurationKeys#MULTI_FIELDS |
| */ |
| public class MultiFieldQueryNodeProcessor extends QueryNodeProcessorImpl { |
| |
| private boolean processChildren = true; |
| |
| public MultiFieldQueryNodeProcessor() { |
| // empty constructor |
| } |
| |
| @Override |
| protected QueryNode postProcessNode(QueryNode node) throws QueryNodeException { |
| |
| return node; |
| |
| } |
| |
| @Override |
| protected void processChildren(QueryNode queryTree) throws QueryNodeException { |
| |
| if (this.processChildren) { |
| super.processChildren(queryTree); |
| |
| } else { |
| this.processChildren = true; |
| } |
| |
| } |
| |
| @Override |
| protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException { |
| |
| if (node instanceof FieldableNode) { |
| this.processChildren = false; |
| FieldableNode fieldNode = (FieldableNode) node; |
| |
| if (fieldNode.getField() == null) { |
| CharSequence[] fields = getQueryConfigHandler().get(ConfigurationKeys.MULTI_FIELDS); |
| |
| if (fields == null) { |
| throw new IllegalArgumentException( |
| "StandardQueryConfigHandler.ConfigurationKeys.MULTI_FIELDS should be set on the QueryConfigHandler"); |
| } |
| |
| if (fields != null && fields.length > 0) { |
| fieldNode.setField(fields[0]); |
| |
| if (fields.length == 1) { |
| return fieldNode; |
| } else { |
| List<QueryNode> children = new ArrayList<>(fields.length); |
| |
| children.add(fieldNode); |
| for (int i = 1; i < fields.length; i++) { |
| try { |
| fieldNode = (FieldableNode) fieldNode.cloneTree(); |
| fieldNode.setField(fields[i]); |
| |
| children.add(fieldNode); |
| } catch (CloneNotSupportedException e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| return new GroupQueryNode(new OrQueryNode(children)); |
| } |
| } |
| } |
| } |
| |
| return node; |
| |
| } |
| |
| @Override |
| protected List<QueryNode> setChildrenOrder(List<QueryNode> children) |
| throws QueryNodeException { |
| return children; |
| } |
| } |