Use of PersistenceContext in annotations - openjpa

Question

Is it possible to use PersistenceContext as annotation for JPA in a normal JAVA class? If not, can you please tell me how to use the PersistenceContext without any annotation?

Answer 1

Yes, you can use #PersistenceContext in any Java class. However, you must specify annotation-config in your Spring configuration, as in the following example:
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xsi:schemaLocation="
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd
http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
<context:annotation-config/>
</beans>
Once you have that specified, you can use #PersistenceContext as follows:
package com.sample.dao.impl
import java.util.List;
import javax.persistence.EntityManager;
import javax.persistence.Query;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
public class CustomerDaoImpl {
#PersistenceContext
private EntityManager em;
public Customer getCustomerByName(String customerName) {
Query query = em.createQuery("SELECT c FROM Customer c WHERE c.name = ?1");
query.setParameter(1, customerName);
List<Customer> results = query.getResultList();
if (results.size() > 0) {
return results.get(0);
}
return null;
}
}