/**
* 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.apache.camel.example.etl;
import java.util.List;
import javax.persistence.EntityManager;
import org.apache.camel.Converter;
import org.apache.camel.Exchange;
import org.apache.camel.component.jpa.JpaConstants;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.transaction.TransactionStatus;
import org.springframework.transaction.support.TransactionCallback;
import org.springframework.transaction.support.TransactionTemplate;
/**
* A Message Transformer of an XML document to a Customer entity bean
*
* @version
*/
// START SNIPPET: example
@Converter
public final class CustomerTransformer {
private static final Logger LOG = LoggerFactory.getLogger(CustomerTransformer.class);
private CustomerTransformer() {
}
/**
* A transformation method to convert a person document into a customer
* entity
*/
@Converter
public static CustomerEntity toCustomer(PersonDocument doc, Exchange exchange) throws Exception {
EntityManager entityManager = exchange.getProperty(JpaConstants.ENTITY_MANAGER, EntityManager.class);
TransactionTemplate transactionTemplate = exchange.getContext().getRegistry().lookupByNameAndType("transactionTemplate", TransactionTemplate.class);
String user = doc.getUser();
CustomerEntity customer = findCustomerByName(transactionTemplate, entityManager, user);
// let's convert information from the document into the entity bean
customer.setUserName(user);
customer.setFirstName(doc.getFirstName());
customer.setSurname(doc.getLastName());
customer.setCity(doc.getCity());
LOG.info("Created object customer: {}", customer);
return customer;
}
/**
* Finds a customer for the given username
*/
private static CustomerEntity findCustomerByName(TransactionTemplate transactionTemplate, final EntityManager entityManager, final String userName) throws Exception {
return transactionTemplate.execute(new TransactionCallback<CustomerEntity>() {
public CustomerEntity doInTransaction(TransactionStatus status) {
entityManager.joinTransaction();
List<CustomerEntity> list = entityManager.createNamedQuery("findCustomerByUsername", CustomerEntity.class).setParameter("userName", userName).getResultList();
CustomerEntity answer;
if (list.isEmpty()) {
answer = new CustomerEntity();
answer.setUserName(userName);
LOG.info("Created a new CustomerEntity {} as no matching persisted entity found.", answer);
} else {
answer = list.get(0);
LOG.info("Found a matching CustomerEntity {} having the userName {}.", answer, userName);
}
return answer;
}
});
}
}
// END SNIPPET: example