Getting the entity manager - spring

Question

i'm using spring data jpa but i want execute some costume query so how can i get the entity manager in my java classes to make entityManager.createQuery(..)
<bean id="entityManagerFactory" class="org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean">
<property name="persistenceUnitName" value="persistenceYous" />
<property name="dataSource" ref="dataSource" />
<property name="packagesToScan" value="persistence" />
<property name="jpaVendorAdapter" ref="jpaVendorAdapter" />
</bean>

Answer 1

You can obtain your EntityManager as in any other spring application:
public class ProductDaoImpl implements ProductDao {
private EntityManager em;
#PersistenceContext
public void setEntityManager(EntityManager em) {
this.em = em;
}
public Collection loadProductsByCategory(String category) {
em. ....
....
}
}
See: http://docs.spring.io/spring/docs/4.0.0.RELEASE/spring-framework-reference/html/orm.html#orm-jpa-straight

Answer 2

In your applicationContext.xml, check that you have the following:
<context:annotation-config />
That will add support for several annotations, such as #PersistenceContext, that injects an EntityManager. So in your Spring-managed beans, you can do:
public class MyClass {
private EntityManager entityManager;
#PersistenceContext
public void setEntityManager(EntityManager em) {
this.entityManager = em
}
public void myMethod() {
Query q = entityManager.createQuery(...);
// ...
}
}
If you want to add suport for just #PersistenceContext, and not the other annotations that <context:annotation-config /> supports, you would delete that from the applicationContext.xml and add the specific BeanPostProcessor:
<bean class="org.springframework.orm.jpa.support.PersistenceAnnotationBeanPostProcessor" scope="singleton">
<!-- Optional configuration of PersistenceAnnotationBeanPostProcessor, for advanced use cases -->
</bean>

Answer 3

Firstly follow this link to get the steps required to implement..
check this link
In second step he uses #Autowired private JdbcOperations operations;
But that doesn't work for me, so i used the following code.. Which worked for me.
#Component
public class MayorRepositoryImpl extends JdbcDaoSupport implements MayorRepositoryCustom {
#Override
public List<Employee> getUsers(String role) {
return getJdbcTemplate().query("Write your custom query",new RowMapper<Employee>(){
#Override
public Employee mapRow(ResultSet rs, int rownumber) throws SQLException {
// Mapping each row and adding to list and returning the list
Employee employeeBean=new Employee();
employeeBean.setId(rs.getInt("id"));
employeeBean.setEmployeeNumber(rs.getString("employeeNumber"));
employeeBean.setName(rs.getString("name"));
employeeBean.setWorkEmailAddress(rs.getString("workEmailAddress"));
employeeBean.setPersonalEmailAddress(rs.getString("personalEmailAddress"));
return employeeBean;
}
});
}
}
This is perfectly working for me..
If you find any difficulty let me know to help you.
Cheers