/*
* 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.exoplatform.services.jcr.impl.core.query;
import javax.jcr.query.InvalidQueryException;
import org.exoplatform.services.jcr.impl.core.LocationFactory;
/**
* This class acts as the central entry point for parsing query statements from
* different query syntaxes into a query tree.
*/
public class QueryParser {
/**
* This class cannot be instanciated.
*/
private QueryParser() {
}
/**
* Parses a query <code>statement</code> according to a query
* <code>language</code> into a query tree.
* <br>
* <code>language</code> must be one of: {@link javax.jcr.query.Query#SQL},
* {@link javax.jcr.query.Query#XPATH}.
*
* @param statement the query statement.
* @param language the language of the query statement.
* @param factory the query node factory.
* @return the root node of the generated query tree.
* @throws InvalidQueryException if an error occurs while parsing the
* statement.
*/
public static QueryRootNode parse(String statement,
String language,
LocationFactory resolver,
QueryNodeFactory factory)
throws InvalidQueryException {
QueryTreeBuilder builder = QueryTreeBuilderRegistry.getQueryTreeBuilder(language);
return builder.createQueryTree(statement, resolver, factory);
}
/**
* Creates a String representation of the QueryNode tree argument
* <code>root</code>. The argument <code>language</code> specifies the
* syntax.
* See also: {@link javax.jcr.query.QueryManager#getSupportedQueryLanguages()}.
*
* @param root the query node tree.
* @param language one of the languages returned by:
* {@link javax.jcr.query.QueryManager#getSupportedQueryLanguages()}.
* @param resolver to resolve QNames.
*
* @return a String representation of the query node tree.
*
* @throws InvalidQueryException if the query node tree cannot be converted
* into a String representation of the given language. This might be due to
* syntax restrictions of the given language. This exception is also thrown
* if <code>language</code> is not one of the supported query languages
* returned by the {@link javax.jcr.query.QueryManager}.
*/
public static String toString(QueryRootNode root,
String language,
LocationFactory resolver)
throws InvalidQueryException {
QueryTreeBuilder builder = QueryTreeBuilderRegistry.getQueryTreeBuilder(language);
return builder.toString(root, resolver);
}
}