I did something similar, you need the generic class to be a constructor argument as well, mine uses hibernate entities, but you could pass in the string of table name.
public class DomainRepository<T> {
@Resource(name = "sessionFactory")
protected SessionFactory sessionFactory;
public DomainRepository(Class genericType) {
this.genericType = genericType;
}
@Transactional(readOnly = true)
public T get(final long id) {
return (T) sessionFactory.getCurrentSession().get(genericType, id);
}
You can then subclass (if you need to) to customize or simply set up you bean in the spring config like below t :
<bean id="tagRepository" class="com.yourcompnay.data.DomainRepository">
<constructor-arg value="com.yourcompnay.domain.Tag"/>
</bean>
So in your code you could then reference tagRepository like so (no other cod eis needed than that posted above, and below) :
@Resource(name = "tagRepository")
private DomainRepository<Tag> tagRepository;
Also, I would call it a repository not a service, a service deals with different types and their interactions (not just one). And for specifically your example using SQL strings :
public final String tableName;
public DomainRepository(String tableName) {
this.tableName = tableName;
}
public List<T> getAll(Integer status) {
Session session = sessionFactory.getCurrentSession();
Query query = session.createQuery("FROM " + tableName + " WHERE status = " + status);
return query.list();
}
and have your beans defined like so
<bean id="addressRepository" class="com.yourcompnay.data.DomainRepository">
<constructor-arg value="address"/>
</bean>
And then you can alsow create subclasses youself where necessary :
public class PersonRepository extends DomainRepository<Person> {
public PersonRepository(){
super("person"); //assumes table name is person
}