/**
* Copyright 2011 meltmedia
*
* 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.xchain.namespaces.hibernate;
import org.apache.commons.jxpath.JXPathContext;
import org.hibernate.Query;
import org.xchain.annotations.Element;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* <p>The <code>list</code> evaluates the Query as a list.</p>
*
* <p>This must reference a <code>query</code>.</p>
*
* <code class="source">
* <xchain:session xmlns:xchain="http://www.xchain.org/hibernate/1.0">
* <xchain:transaction>
* ...
* <xchain:query query="'from Entity'">
* ...
* <list result="$myList"/>
* ...
* </xchain:query>
* ...
* </xchain:transaction>
* </xchain:session>
* </code>
*
* @author Devon Tackett
* @author Christian Trimble
* @author Josh Kennedy
*
* @see SessionCommand
* @see org.hibernate.Query#list()
*/
@Element(localName="list")
public abstract class ListCommand
extends AbstractQueryResultCommand
{
private static Logger log = LoggerFactory.getLogger( ListCommand.class );
/**
* Evaluate the query as a list.
*/
public boolean execute( JXPathContext context )
throws Exception
{
try {
Query query = getQuery(context);
if (query == null) {
if( log.isDebugEnabled() ) {
log.debug("Could not get query for list command.");
throw new Exception("A list command must have a query.");
}
}
// Execute the query and store the result.
storeValue(context, query.list());
}
catch( Exception e ) {
if( log.isErrorEnabled() ) {
log.error("Could not execute query.", e);
}
throw e;
}
// The query is built and executed.
return false;
}
}