Spring Boot – Pagination and Sorting Project

Pagination is often helpful when we have a large dataset and we want to present it to the user in smaller chunks.
Also, we often need to sort that data by some criteria while paging.

Installation

1) Clone the Repo from here CLICK HERE

2) Import Maven based project in any of your Favourite IDE.

./mvnw spring-boot:run

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Output

Open in Browser

Access H2 Database.

http://localhost:8080/h2-console

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Output

Usage

SortingRepository.java

@Repository
public interface SortingRepository extends PagingAndSortingRepository<Student, Integer>  {

}

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StudentService.java

public PaginatedStudentResponse readStudent(Pageable pageable) {
        Page<Student> students = studentRepository.findAll(pageable);
        return PaginatedStudentResponse.builder()
                .numberOfItems(students.getTotalElements()).numberOfPages(students.getTotalPages())
                .studentList(students.getContent())
                .build();

    }

    public List<Student> getAllStudents(Integer pageNo, Integer pageSize, String sortBy)
        {
            Pageable paging = PageRequest.of(pageNo, pageSize, Sort.by(sortBy));
            Page<Student> pageResult = studentRepository.findAll(paging);

            if(pageResult.hasContent()) {
                return pageResult.getContent();
            }
            else
            {
                return new ArrayList<Student>();
            }
        }

    public Student createStudent(Student student) {
        return studentRepository.save(student);
    }

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PaginationController.java

    @GetMapping
    public ResponseEntity<List<Student>> getAllStudents(
            @RequestParam(defaultValue = "0") Integer pageNo,
            @RequestParam(defaultValue = "10") Integer pageSize,
            @RequestParam(defaultValue = "id") String sortBy)
    {
        List<Student> list = service.getAllStudents(pageNo, pageSize, sortBy);

        return new ResponseEntity<List<Student>>(list, new HttpHeaders(),HttpStatus.OK);
    }

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StudentController.java

@Autowired
    private StudentService studentService;

    @GetMapping("/student/search")
    public ResponseEntity<PaginatedStudentResponse> readStudent(Pageable pageable) {
        return ResponseEntity.ok(studentService.readStudent(pageable));
    }

    @PostMapping("/student")
    public ResponseEntity<Student> createProduct(@RequestBody Student student){
        return ResponseEntity.ok().body(this.studentService.createStudent(student));
    }

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Configuration

application.properties

spring.jpa.show-sql = true

# Enabling H2 Console spring.datasource.url=jdbc:h2:mem:testdb
spring.jpa.defer-datasource-initialization=true
spring.h2.console.enabled=true

# Enable Web Access spring.h2.console.settings.web-allow-others=true

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Credits

https://howtodoinjava.com

原文链接：Spring Boot – Pagination and Sorting Project