Let's write a few tests to use the sorting and pagination capabilities of UserRepository. The base of the test is very similar to TodoRepositoryTest:

    @DataJpaTest
    @RunWith(SpringRunner.class)
    public class UserRepositoryTest {
      @Autowired
      UserRepository userRepository;
      @Autowired
      TestEntityManager entityManager;
    }

Let's write a simple test to sort users and print the users to the log:

    @Test
    public void testing_sort_stuff() {
      Sort sort = new Sort(Sort.Direction.DESC, "name")
      .and(new Sort(Sort.Direction.ASC, "userid"));
    Iterable<User> users = userRepository.findAll(sort);
    for (User user : users) {
      System.out.println(user);
     }
   }

Important things to note are as follows:

• new Sort(Sort.Direction.DESC, "name"): We would want to sort by name in descending order.
• and(new Sort(Sort.Direction.ASC, "userid")): The and() method is a conjunction method to combine different sort configurations. In this example, we are adding secondary criteria to sort by user ID in the ascending order.
• userRepository.findAll(sort): The sort criteria are passed as a parameter to the findAll() method.

The output of the preceding test is as shown as follows. The users are sorted in descending order by name:

User [id=4, userid=UserId4, name=User Name 4, todos=0]
User [id=3, userid=UserId3, name=User Name 3, todos=0]
User [id=2, userid=UserId2, name=User Name 2, todos=1]
User [id=1, userid=UserId1, name=User Name 1, todos=2]

The test for the pageable is shown as follows:

    @Test
    public void using_pageable_stuff() {
      PageRequest pageable = new PageRequest(0, 2);
      Page<User> userPage = userRepository.findAll(pageable);
      System.out.println(userPage);
      System.out.println(userPage.getContent());
    }

The output of the test is shown as follows:

Page 1 of 2 containing com.in28minutes.model.User instances
[User [id=1, userid=UserId1, name=User Name 1, todos=2],
User [id=2, userid=UserId2, name=User Name 2, todos=1]]

Important things to note are as follows:

• new PageRequest(0, 2): We are requesting the first page (index 0) and setting the size of each page to two
• userRepository.findAll(pageable): The PageRequest object is sent as a parameter to the findAll method
• Page 1 of 2 : The output shows that we are looking at the first page in a total of two pages

A couple of important things to note about PageRequest are as follows:

• The PageRequest object has the next(), previous(), and first() methods to traverse the pages
• The PageRequest constructor (public PageRequest(int page, int size, Sort sort)) also accepts a third parameter--Sort order

Important methods in Page and its child interface, Slice, are listed as follows:

• int getTotalPages(): Returns the number of result pages
• long getTotalElements(): Returns the total number of elements in all pages
• int getNumber(): Returns the number of the current page
• int getNumberOfElements(): Returns the number of elements in the current page
• List<T> getContent(): Gets the content of the current slice (or page) as a list
• boolean hasContent(): Returns if the current slice has any elements
• boolean isFirst(): Returns if this is the first slice
• boolean isLast(): Returns if this is the last slice
• boolean hasNext(): Returns if there is a next slice
• boolean hasPrevious(): Returns if there is a previous slice
• Pageable nextPageable(): Gets access to the next slice
• Pageable previousPageable(): Gets access to the previous slice