How to filter a PageRequest in spring

Question

When I make a request about all the news that I have in my database I use a PageRequest like this:

public Page<StatusUpdate> getPageSiteUser(int pageNumber) {

    PageRequest request = new PageRequest(pageNumber-1, pageSize, Sort.Direction.DESC, "added");

    return statusUpdateDao.findAll(request);
}

And it shows all the news in each page sorted in perfect order.

But now, I want to select the news created by one user, in the same Pageable format (not all the news) and I do not find how to do it, so I must be making a stupid mistake somewhere... it should be something like...

 public Page<StatusUpdate> findMyStatusUpdates(Long user_id, int pageNumber) {

    PageRequest request = new PageRequest(pageNumber-1, pageSize, Sort.Direction.DESC, "added"); 
    return statusUpdateDao.findAll(request);
}

Please, answer with a link to the the theory if you can. The documentation talks about sorting, not making the actual selection (enter link description here)

Answer 1

You can combine a query, to filter by the user, with a pageable request. The query can be created by Spring based on the method name.

Take a look to the documentation:

Spring data JPA Query creation

Using Pageable, Slice and Sort in query methods

In your case, without seeing your code, I guess you only need to include in your repository a method like:

public interface StatusUpdateRepository extends Repository<StatusUpdate, Long> {
  //finBy<column_name>
  Page<User> findByUser(Long userId, Pageable pageable);
}

Answer 2

You can also send a PageRequest to an existing filter in your repo. You can create a repository method, filter them according to your business need.

Let's say you would like to find posts by supplying a user, status attributes and then order them by their creation date in descending order.

One might not desire all posts being included in the Page object while sending them to a Pager, before adding to the Model model.

This is simply equivalent to a sql query as such:

select * from Post where user=user and status=status order by createdAt desc

--

public interface BlogRepository extends PagingAndSortingRepository<Post, Long> {

Page<Post> findByUserAndStatusOrderByCreatedAtDesc(PageRequest pageRequest, 
User user, boolean status);

}

and in your controller, use its implementation(postService) along with a new PageRequest object like:

Page<Post> filteredPosts = postService.findByUserAndStatusOrderByCreatedAtDesc(PageRequest.of(evalPage, evalPageSize), user, status);

this works fine for 2.x.x; whereas you better use below for 1.x.x

Page<Post> filteredPosts = 
postService.findByUserAndStatusOrderByCreatedAtDesc(new PageRequest(evalPage, 
evalPageSize), user, status);

This repo guided me up to a certain point on this matter with paging logic etc.

Just had to change from ModelView to Model in the controller's argument and returned String (template's name) instead.