I want the user to be able to specify the limit (the size of the amount returned) and offset (the first record returned / index returned) in my query method.
Here are my classes without any paging capabilities. My entity:
@Entity
public Employee {
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
private int id;
@Column(name="NAME")
private String name;
//getters and setters
}
My repository:
public interface EmployeeRepository extends JpaRepository<Employee, Integer> {
@Query("SELECT e FROM Employee e WHERE e.name LIKE :name ORDER BY e.id")
public List<Employee> findByName(@Param("name") String name);
}
My service interface:
public interface EmployeeService {
public List<Employee> findByName(String name);
}
My service implementation:
public class EmployeeServiceImpl {
@Resource
EmployeeRepository repository;
@Override
public List<Employee> findByName(String name) {
return repository.findByName(name);
}
}
Now here is my attempt at providing paging capabilities that support offset and limit. My entity class remains the same.
My "new" repository takes in a pageable parameter:
public interface EmployeeRepository extends JpaRepository<Employee, Integer> {
@Query("SELECT e FROM Employee e WHERE e.name LIKE :name ORDER BY e.id")
public List<Employee> findByName(@Param("name") String name, Pageable pageable);
}
My "new" service interface takes in two additional parameters:
public interface EmployeeService {
public List<Employee> findByName(String name, int offset, int limit);
}
My "new" service implementation:
public class EmployeeServiceImpl {
@Resource
EmployeeRepository repository;
@Override
public List<Employee> findByName(String name, int offset, int limit) {
return repository.findByName(name, new PageRequest(offset, limit);
}
}
This however isn't what i want. PageRequest specifies the page and size (page # and the size of the page). Now specifying the size is exactly what I want, however, I don't want to specify the starting page #, I want the user to be able to specify the starting record / index. I want something similar to
public List<Employee> findByName(String name, int offset, int limit) {
TypedQuery<Employee> query = entityManager.createQuery("SELECT e FROM Employee e WHERE e.name LIKE :name ORDER BY e.id", Employee.class);
query.setFirstResult(offset);
query.setMaxResults(limit);
return query.getResultList();
}
Specifically the setFirstResult() and setMaxResult() methods. But I can't use this method because I want to use the Employee repository interface. (Or is it actually better to define queries through the entityManager?)
Is there a way to specify the offset without using the entityManager?
