/*
* Copyright (c) 2008, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
*
* Licensed 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.wso2.carbon.registry.core.jdbc.queries;
import org.wso2.carbon.registry.core.Collection;
import org.wso2.carbon.registry.core.Registry;
import org.wso2.carbon.registry.core.RegistryConstants;
import org.wso2.carbon.registry.core.Resource;
import org.wso2.carbon.registry.core.config.QueryProcessorConfiguration;
import org.wso2.carbon.registry.core.config.RegistryContext;
import org.wso2.carbon.registry.core.dataaccess.DataAccessManager;
import org.wso2.carbon.registry.core.dataaccess.QueryProcessor;
import org.wso2.carbon.registry.core.exceptions.RegistryException;
import org.wso2.carbon.user.core.UserRealm;
import java.lang.reflect.Constructor;
import java.util.HashMap;
import java.util.Map;
/**
* The class is handling the query processing
*/
public class QueryProcessorManager {
private Map<String, QueryProcessor> queryProcessors = new HashMap<String, QueryProcessor>();
/**
* Construct a query processor manager object from the data source and registry context.
*
* @param dataAccessManager the data access manager object
* @param registryContext registry context
*
* @throws RegistryException throws if the construction failed.
*/
public QueryProcessorManager(DataAccessManager dataAccessManager, RegistryContext registryContext)
throws RegistryException {
queryProcessors.put(RegistryConstants.SQL_QUERY_MEDIA_TYPE,
dataAccessManager.getQueryProcessor());
// add run-time query processors configured using registry.xml
if (registryContext != null) {
for (Object queryProcessorObject : registryContext.getQueryProcessors()) {
QueryProcessorConfiguration configuration =
(QueryProcessorConfiguration) queryProcessorObject;
try {
Class qpClass = Class.forName(configuration.getProcessorClassName());
Constructor constructor =
qpClass.getConstructor(DataAccessManager.class, UserRealm.class);
QueryProcessor queryProcessor =
(QueryProcessor) constructor.newInstance(dataAccessManager);
queryProcessors.put(configuration.getQueryType(), queryProcessor);
} catch (ClassNotFoundException e) {
String msg = "Could not find the query processor class for query type: " +
configuration.getQueryType();
throw new RegistryException(msg, e);
} catch (Exception e) {
String msg = "Failed to initiate query processor for query type: " +
configuration.getQueryType();
throw new RegistryException(msg, e);
}
}
}
}
/**
* Return the query processor with the given type.
*
* @param queryType the query type
*
* @return the query processor of the given type.
*/
@SuppressWarnings("unused")
public QueryProcessor getQueryProcessor(String queryType) {
return queryProcessors.get(queryType);
}
/**
* Execute a query using the query processor associated with the media type of the query.
*
* @param registry the registry
* @param queryResource the query as a resource.
* @param parameters the custom parameters to be passed to the query.
*
* @return a collection containing query results as children
* @throws RegistryException throws if the query execution failed.
*/
public Collection executeQuery(Registry registry, Resource queryResource, Map parameters)
throws RegistryException {
if (queryResource.getMediaType() == null || queryResource.getMediaType().length() == 0) {
String msg = "Failed to execute query at path: " + queryResource.getPath() +
". Query resources should have a media type to map to a query processor.";
throw new RegistryException(msg);
}
QueryProcessor queryProcessor =
queryProcessors.get(queryResource.getMediaType());
if (queryProcessor == null) {
String msg = "Failed to execute query at path: " + queryResource.getPath() +
". No query processor is associated with the query type: " +
queryResource.getMediaType();
throw new RegistryException(msg);
}
return queryProcessor.executeQuery(registry, queryResource, parameters);
}
}