package org.apache.lucene.queryparser.flexible.standard.processors;
/*
* 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.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.AndQueryNode;
import org.apache.lucene.queryparser.flexible.core.nodes.BooleanQueryNode;
import org.apache.lucene.queryparser.flexible.core.nodes.GroupQueryNode;
import org.apache.lucene.queryparser.flexible.core.nodes.ModifierQueryNode;
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.nodes.ModifierQueryNode.Modifier;
import org.apache.lucene.queryparser.flexible.core.parser.SyntaxParser;
import org.apache.lucene.queryparser.flexible.core.processors.QueryNodeProcessor;
import org.apache.lucene.queryparser.flexible.standard.config.StandardQueryConfigHandler;
import org.apache.lucene.queryparser.flexible.standard.config.StandardQueryConfigHandler.ConfigurationKeys;
import org.apache.lucene.queryparser.flexible.standard.config.StandardQueryConfigHandler.Operator;
import org.apache.lucene.queryparser.flexible.standard.nodes.BooleanModifierNode;
/**
* The {@link SyntaxParser}
* generates query node trees that consider the boolean operator precedence, but
* Lucene current syntax does not support boolean precedence, so this processor
* remove all the precedence and apply the equivalent modifier according to the
* boolean operation defined on an specific query node. <br/>
* <br/>
* If there is a {@link GroupQueryNode} in the query node tree, the query node
* tree is not merged with the one above it.
*
* Example: TODO: describe a good example to show how this processor works
*
* @see org.apache.lucene.queryparser.flexible.standard.config.StandardQueryConfigHandler
* @deprecated use {@link BooleanQuery2ModifierNodeProcessor} instead
*/
public class GroupQueryNodeProcessor implements QueryNodeProcessor {
private ArrayList<QueryNode> queryNodeList;
private boolean latestNodeVerified;
private QueryConfigHandler queryConfig;
private Boolean usingAnd = false;
public GroupQueryNodeProcessor() {
// empty constructor
}
@Override
public QueryNode process(QueryNode queryTree) throws QueryNodeException {
Operator defaultOperator = getQueryConfigHandler().get(ConfigurationKeys.DEFAULT_OPERATOR);
if (defaultOperator == null) {
throw new IllegalArgumentException(
"DEFAULT_OPERATOR should be set on the QueryConfigHandler");
}
this.usingAnd = StandardQueryConfigHandler.Operator.AND == defaultOperator;
if (queryTree instanceof GroupQueryNode) {
queryTree = ((GroupQueryNode) queryTree).getChild();
}
this.queryNodeList = new ArrayList<QueryNode>();
this.latestNodeVerified = false;
readTree(queryTree);
List<QueryNode> actualQueryNodeList = this.queryNodeList;
for (int i = 0; i < actualQueryNodeList.size(); i++) {
QueryNode node = actualQueryNodeList.get(i);
if (node instanceof GroupQueryNode) {
actualQueryNodeList.set(i, process(node));
}
}
this.usingAnd = false;
if (queryTree instanceof BooleanQueryNode) {
queryTree.set(actualQueryNodeList);
return queryTree;
} else {
return new BooleanQueryNode(actualQueryNodeList);
}
}
/**
*/
private QueryNode applyModifier(QueryNode node, QueryNode parent) {
if (this.usingAnd) {
if (parent instanceof OrQueryNode) {
if (node instanceof ModifierQueryNode) {
ModifierQueryNode modNode = (ModifierQueryNode) node;
if (modNode.getModifier() == Modifier.MOD_REQ) {
return modNode.getChild();
}
}
} else {
if (node instanceof ModifierQueryNode) {
ModifierQueryNode modNode = (ModifierQueryNode) node;
if (modNode.getModifier() == Modifier.MOD_NONE) {
return new BooleanModifierNode(modNode.getChild(), Modifier.MOD_REQ);
}
} else {
return new BooleanModifierNode(node, Modifier.MOD_REQ);
}
}
} else {
if (node.getParent() instanceof AndQueryNode) {
if (node instanceof ModifierQueryNode) {
ModifierQueryNode modNode = (ModifierQueryNode) node;
if (modNode.getModifier() == Modifier.MOD_NONE) {
return new BooleanModifierNode(modNode.getChild(), Modifier.MOD_REQ);
}
} else {
return new BooleanModifierNode(node, Modifier.MOD_REQ);
}
}
}
return node;
}
private void readTree(QueryNode node) {
if (node instanceof BooleanQueryNode) {
List<QueryNode> children = node.getChildren();
if (children != null && children.size() > 0) {
for (int i = 0; i < children.size() - 1; i++) {
readTree(children.get(i));
}
processNode(node);
readTree(children.get(children.size() - 1));
} else {
processNode(node);
}
} else {
processNode(node);
}
}
private void processNode(QueryNode node) {
if (node instanceof AndQueryNode || node instanceof OrQueryNode) {
if (!this.latestNodeVerified && !this.queryNodeList.isEmpty()) {
this.queryNodeList.add(applyModifier(this.queryNodeList
.remove(this.queryNodeList.size() - 1), node));
this.latestNodeVerified = true;
}
} else if (!(node instanceof BooleanQueryNode)) {
this.queryNodeList.add(applyModifier(node, node.getParent()));
this.latestNodeVerified = false;
}
}
@Override
public QueryConfigHandler getQueryConfigHandler() {
return this.queryConfig;
}
@Override
public void setQueryConfigHandler(QueryConfigHandler queryConfigHandler) {
this.queryConfig = queryConfigHandler;
}
}