package org.apache.lucene.queryParser.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.List;
import org.apache.lucene.messages.MessageImpl;
import org.apache.lucene.queryParser.core.QueryNodeException;
import org.apache.lucene.queryParser.core.config.QueryConfigHandler;
import org.apache.lucene.queryParser.core.messages.QueryParserMessages;
import org.apache.lucene.queryParser.core.nodes.QueryNode;
import org.apache.lucene.queryParser.core.processors.QueryNodeProcessorImpl;
import org.apache.lucene.queryParser.core.util.UnescapedCharSequence;
import org.apache.lucene.queryParser.standard.config.AllowLeadingWildcardAttribute;
import org.apache.lucene.queryParser.standard.nodes.WildcardQueryNode;
import org.apache.lucene.queryParser.standard.parser.EscapeQuerySyntaxImpl;
/**
* This processor verifies if the attribute
* {@link AllowLeadingWildcardAttribute} is defined in the
* {@link QueryConfigHandler}. If it is and leading wildcard is not allowed, it
* looks for every {@link WildcardQueryNode} contained in the query node tree
* and throws an exception if any of them has a leading wildcard ('*' or '?'). <br/>
*
* @see AllowLeadingWildcardAttribute
*/
public class AllowLeadingWildcardProcessor extends QueryNodeProcessorImpl {
public AllowLeadingWildcardProcessor() {
// empty constructor
}
@Override
public QueryNode process(QueryNode queryTree) throws QueryNodeException {
if (getQueryConfigHandler().hasAttribute(AllowLeadingWildcardAttribute.class)) {
AllowLeadingWildcardAttribute alwAttr= getQueryConfigHandler().getAttribute(AllowLeadingWildcardAttribute.class);
if (!alwAttr.isAllowLeadingWildcard()) {
return super.process(queryTree);
}
}
return queryTree;
}
@Override
protected QueryNode postProcessNode(QueryNode node) throws QueryNodeException {
if (node instanceof WildcardQueryNode) {
WildcardQueryNode wildcardNode = (WildcardQueryNode) node;
if (wildcardNode.getText().length() > 0) {
// Validate if the wildcard was escaped
if (UnescapedCharSequence.wasEscaped(wildcardNode.getText(), 0))
return node;
switch (wildcardNode.getText().charAt(0)) {
case '*':
case '?':
throw new QueryNodeException(new MessageImpl(
QueryParserMessages.LEADING_WILDCARD_NOT_ALLOWED, node
.toQueryString(new EscapeQuerySyntaxImpl())));
}
}
}
return node;
}
@Override
protected QueryNode preProcessNode(QueryNode node) throws QueryNodeException {
return node;
}
@Override
protected List<QueryNode> setChildrenOrder(List<QueryNode> children)
throws QueryNodeException {
return children;
}
}