複数検索項目、ページネーションに対応した custom Repositoryクラス　※動作検証していません

CustomRepository.java

@Repository
public interface UserRepository extends 
	JpaRepository<User, Long>,
	JpaSpecificationExecutor<User>,
	UserRepositoryCustom {}

@Repository
public interface UserRepositoryCustom {
    public List<User> findUsers(Map<String,Object> params);
}

@Repository
public class UserRepositoryImpl implements UserRepositoryCustom {
    @Autowired
    EntityManager entityManager;

    public List<User> findUsers(Map<String,Object> params) {
		
	StringBilder sql = new StringBilder();

	// params をもとに動的SQLを生成
	sql.append("SELECT c FROM User c WHERE c.name = :name");

  	TypedQuery<User> query = entityManager.createQuery(sql, User.class);

  	for(Map.Entry<String, Object> e : params.entrySet()){
  		query.setParameter(e.getKey(), e.getValue());
  	}

	int pageNumber = 1;
	int pageSize = 10;
	query.setFirstResult((pageNumber-1) * pageSize); 
	query.setMaxResults(pageSize);
	return query.getResultList();
    }
}

// link
// https://terasolunaorg.github.io/guideline/public_review/ArchitectureInDetail/DataAccessJpa.html#id20
// http://www.objectdb.com/java/jpa/query/parameter
// http://qiita.com/tag1216/items/55742fdb442e5617f727
// http://www.baeldung.com/jpa-pagination