[FIXED] Cache with JpaRepository

Issue

Hi I have extended a JpaRepository interface in following way.

public interface StudentRepository extends JpaRepository<Student,Integer>
{
@Query(value= "SELECT s.id FROM student as s where s.createdat >  ADDDATE(CURRENT_DATE, :maxage ", nativeQuery = true )
public List<Integer> findWaitingStudentIds(@Param("maxage")int maxAge);
}

Here is the Entity class.

@Entity(name="student ")
public class Student implements Serializable {
    @Id
    @GeneratedValue(strategy=GenerationType.AUTO)
    @Column(unique=true, nullable=false)
    private Integer  id;
    @Temporal(TemporalType.TIMESTAMP)
    @Column(updatable = false,insertable = false)
    private Date createdat;  
}

I want to add cache for "List findWaitingStudentIds" method. How can I achieve this?

Solution

I can copy paste my answer from this StackOverflow question:

How should I implement a cache object/system in Spring?

Spring introduced abstraction for Cache in 3.x RELEASE. You can read about it in official Spring documentation (the site is down today for some reason :)), or at this post for example.

http://dzone.com/articles/spring-cache-abstraction-0

With this abstraction, all you need to do to enable cache is to add some annotations to your services, like

To add value to the cache

@Cacheable("customers")
public Customer findCustomer(long customerId) {...}

To remove value to the cache

@CacheEvict(value="customer", allEntries = true)
public void removeAllCustomers(long customerId) {...}

Answered By - mavarazy