java JPA CriteriaQuery 实现 Spring Data Pageable.getSort()
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JPA CriteriaQuery implements Spring Data Pageable.getSort()
提问by Javatar
I used JPA CriteriaQuery to build my dynamic Query and pass in a Spring Data Pageable object:
我使用 JPA CriteriaQuery 来构建我的动态查询并传入一个 Spring Data Pageable 对象：
sort=name,desc
At the backend I have a method in my Repository to support dynamic query:
在后端，我的存储库中有一个方法来支持动态查询：
public Page<User> findByCriteria(String username, Pageable page) {
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<User> cq = cb.createQuery(User.class);
Root<User> iRoot = cq.from(User.class);
List<Predicate> predicates = new ArrayList<Predicate>();
if (StringUtils.isNotEmpty(username)) {
predicates.add(cb.like(cb.lower(iRoot.<String>get("username")), "%" + username.toLowerCase() + "%"));
}
Predicate[] predArray = new Predicate[predicates.size()];
predicates.toArray(predArray);
cq.where(predArray);
TypedQuery<User> query = em.createQuery(cq);
int totalRows = query.getResultList().size();
query.setFirstResult(page.getPageNumber() * page.getPageSize());
query.setMaxResults(page.getPageSize());
Page<User> result = new PageImpl<User>(query.getResultList(), page, totalRows);
return result;
}
Note: I put only one param for demo purpose.
注意：为了演示目的，我只放了一个参数。
However the returned data is unsorted therefore I would like to ask is that any way to implement Pageable in CriteriaQuery.
然而，返回的数据是未排序的，因此我想问的是在 CriteriaQuery 中实现 Pageable 的任何方式。
回答by Angelo Immediata
In your criteria query i see no sort information I'd write in this way:
在您的标准查询中，我看不到我会以这种方式编写的排序信息：
CriteriaBuilder cb = em.getCriteriaBuilder();
CriteriaQuery<User> cq = cb.createQuery(User.class);
Root<User> iRoot = cq.from(User.class);
List<Predicate> predicates = new ArrayList<Predicate>();
if (StringUtils.isNotEmpty(username)) {
predicates.add(cb.like(cb.lower(iRoot.<String>get("username")), "%" + username.toLowerCase() + "%"));
}
Predicate[] predArray = new Predicate[predicates.size()];
predicates.toArray(predArray);
cq.where(predArray);
List<Order> orders = new ArrayList<Order>(2);
orders.add(cb.asc(iRoot.get("name")));
orders.add(cb.asc(iRoot.get("desc")));
cq.orderBy(orders);
TypedQuery<User> query = em.createQuery(cq);
Page<User> result = new PageImpl<User>(query.getResultList(), page, totalRows);
return result;
I didn't test it but it should work
我没有测试它，但它应该工作
Angelo
安杰洛
回答by Konrad Pocz?tek
You can add sorting using QueryUtils from spring:
query.orderBy(QueryUtils.toOrders(pageable.getSort(), root, builder));
您可以从 spring 使用 QueryUtils 添加排序：
query.orderBy(QueryUtils.toOrders(pageable.getSort(), root, builder));
