Spring Data JPA allows query methods to have a special parameter Pageable to apply pagination. For example:
public List<Employee> findByDept(String deptName, Pageable pageable)
Pageable is an interface which contains requested page information. We can use it's implementation PageRequest which has various factory methods:
PageRequest of(int page, int size)
Where: page - zero-based page index. size - the size of the page to be returned.
Example:
List<Employee> list = repo.findByDept("Sales", PageRequest.of(0, 5));
Pagination with sorting
We can use following method of PageRequest to apply sorting as well:
public static PageRequest of(int page, int size, Sort sort)
Example:
List<Employee> list = repo.findByDept("Sales", PageRequest.of(0, 5, Sort.by("salary")));
Pagination can be applied to both query methodsor declared queries by using @Query.
Example
Entity
@Entity
public class Employee {
private @Id
@GeneratedValue
Long id;
private String name;
private String dept;
private int salary;
.............
}
Repository
package com.logicbig.example;
import org.springframework.data.domain.Pageable;
import org.springframework.data.repository.CrudRepository;
import java.util.List;
public interface EmployeeRepository extends CrudRepository<Employee, Long> {
public List<Employee> findByDept(String deptName, Pageable pageable);
}
Example Client
@Component
public class ExampleClient {
@Autowired
private EmployeeRepository repo;
public void run() {
List<Employee> employees = createEmployees();
repo.saveAll(employees);
System.out.println(" -- finding all employees --");
Iterable<Employee> all = repo.findAll();
all.forEach(System.out::println);
System.out.println(" -- paginating where dept is Sales --");
long count = repo.count();
int pageSize = 2;
long pages = count / pageSize;
for (int i = 0; i < pages; i++) {
System.out.printf("page num: %s%n", i);
List<Employee> list = repo.findByDept("Sales", PageRequest.of(i, pageSize));
list.forEach(System.out::println);
}
System.out.println(" -- paginating with sorting by salaries` where dept is Sales --");
for (int i = 0; i < pages; i++) {
System.out.printf("page num: %s%n", i);
List<Employee> list = repo.findByDept("Sales",
PageRequest.of(i, pageSize, Sort.by("salary").descending()));
list.forEach(System.out::println);
}
}
private List<Employee> createEmployees() {
return Arrays.asList(
Employee.create("Diana", "Sales", 2000),
Employee.create("Mike", "Sales", 1000),
Employee.create("Rose", "IT", 4000),
Employee.create("Sara", "Sales", 3000),
Employee.create("Andy", "Sales", 3000),
Employee.create("Charlie", "Sales", 2500),
Employee.create("Jim", "Sales", 4500),
Employee.create("Sam", "Sales", 2500)
);
}
}
Main class
public class ExampleMain {
public static void main(String[] args) {
AnnotationConfigApplicationContext context =
new AnnotationConfigApplicationContext(AppConfig.class);
ExampleClient exampleClient = context.getBean(ExampleClient.class);
exampleClient.run();
EntityManagerFactory emf = context.getBean(EntityManagerFactory.class);
emf.close();
}
} -- finding all employees -- Employee{id=1, name='Diana', dept='Sales', salary=2000} Employee{id=2, name='Mike', dept='Sales', salary=1000} Employee{id=3, name='Rose', dept='IT', salary=4000} Employee{id=4, name='Sara', dept='Sales', salary=3000} Employee{id=5, name='Andy', dept='Sales', salary=3000} Employee{id=6, name='Charlie', dept='Sales', salary=2500} Employee{id=7, name='Jim', dept='Sales', salary=4500} Employee{id=8, name='Sam', dept='Sales', salary=2500} -- paginating where dept is Sales -- page num: 0 Employee{id=1, name='Diana', dept='Sales', salary=2000} Employee{id=2, name='Mike', dept='Sales', salary=1000} page num: 1 Employee{id=4, name='Sara', dept='Sales', salary=3000} Employee{id=5, name='Andy', dept='Sales', salary=3000} page num: 2 Employee{id=6, name='Charlie', dept='Sales', salary=2500} Employee{id=7, name='Jim', dept='Sales', salary=4500} page num: 3 Employee{id=8, name='Sam', dept='Sales', salary=2500} -- paginating with sorting by salaries` where dept is Sales -- page num: 0 Employee{id=7, name='Jim', dept='Sales', salary=4500} Employee{id=5, name='Andy', dept='Sales', salary=3000} page num: 1 Employee{id=5, name='Andy', dept='Sales', salary=3000} Employee{id=6, name='Charlie', dept='Sales', salary=2500} page num: 2 Employee{id=6, name='Charlie', dept='Sales', salary=2500} Employee{id=1, name='Diana', dept='Sales', salary=2000} page num: 3 Employee{id=2, name='Mike', dept='Sales', salary=1000}
Example ProjectDependencies and Technologies Used: - spring-data-jpa 2.0.7.RELEASE: Spring Data module for JPA repositories.
Uses org.springframework:spring-context version 5.0.6.RELEASE - hibernate-core 5.3.1.Final: Hibernate's core ORM functionality.
Implements javax.persistence:javax.persistence-api version 2.2 - h2 1.4.197: H2 Database Engine.
- JDK 1.8
- Maven 3.3.9
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