Spring Boot | Spring Data JPA | Pagination and Sorting

วันนี้เราจะมาดูตัวอย่างการใช้งาน Sprng JPA ในการทำ Pagination และ Sorting กันแบบง่ายๆ นะครับ เราจะใช้ Inmemory Database กันเพื่อที่ว่าจะได้ง่ายต่อการทำตัวอย่างนะครับ เช่นเคยเราจะใช้ Spring Boot with Maven กันนะครับ

เปิด project ด้วย Intellij จะได้ pom ไฟล์ ดังนี้

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>
   <parent>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-parent</artifactId>
      <version>2.5.4</version>
      <relativePath/> <!-- lookup parent from repository -->
   </parent>
   <groupId>com.zencode.jpa</groupId>
   <artifactId>jpa-example</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <name>jpa-example</name>
   <description>Demo project for Spring Boot</description>
   <properties>
      <java.version>1.8</java.version>
   </properties>
   <dependencies>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-data-jpa</artifactId>
      </dependency>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-web</artifactId>
      </dependency>

      <dependency>
         <groupId>com.h2database</groupId>
         <artifactId>h2</artifactId>
         <scope>runtime</scope>
      </dependency>
      <dependency>
         <groupId>org.projectlombok</groupId>
         <artifactId>lombok</artifactId>
         <optional>true</optional>
      </dependency>
      <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-test</artifactId>
         <scope>test</scope>
      </dependency>
   </dependencies>

   <build>
      <plugins>
         <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
            <configuration>
               <excludes>
                  <exclude>
                     <groupId>org.projectlombok</groupId>
                     <artifactId>lombok</artifactId>
                  </exclude>
               </excludes>
            </configuration>
         </plugin>
      </plugins>
   </build>

</project>

เพิ่ม application.properties ครับ

spring.user.datasource.driver-class-name=org.h2.Driver
spring.datasource.url=jdbc:h2:mem:customerDB;DB_CLOSE_DELAY=-1
spring.datasource.username=sa
spring.datasource.password=

spring.jpa.show-sql=true
spring.h2.console.enabled=true
spring.h2.console.path=/h2
spring.jpa.hibernate.ddl-auto=create
security.headers.frame=false

ตอไปสร้าง Entity class ของ Customer กันครับ

package com.zencode.jpa.jpaexample.entity;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;


import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;

@Data
@Entity
@Table(name = "customers")
@NoArgsConstructor
@AllArgsConstructor
public class Customer {

    @Id
    @GeneratedValue
    private int id;
    private String name;
    private int salary;
}

ต่อไปสร้าง CustomerRepository

package com.zencode.jpa.jpaexample.repository;

import com.zencode.jpa.jpaexample.entity.Customer;
import org.springframework.data.jpa.repository.JpaRepository;

public interface CustomerRepository extends JpaRepository<Customer, Integer> {
}

สร้าง CustomerService

package com.zencode.jpa.jpaexample.service;

import com.zencode.jpa.jpaexample.entity.Customer;
import com.zencode.jpa.jpaexample.repository.CustomerRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;
import java.util.List;
import java.util.Random;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

@Service
public class CustomerService {

    @Autowired
    private CustomerRepository customerRepository;

    @PostConstruct
    public void InitData() {
        List<Customer> customerList = IntStream.range(1, 300)
                .mapToObj(i -> new Customer(i,"Customer " + i, new Random().nextInt(10000)))
                .collect(Collectors.toList());
        customerRepository.saveAll(customerList);
    }

    public List<Customer> findAllCustomers() {
       return customerRepository.findAll();
    }
}

เราจะ initial data ตอนที application ของเรา start นะครับ

ลองเช้า H2 Console กันครับ

ว้าว ได้แล้ว ต่อไปสร้าง Controller

package com.zencode.jpa.jpaexample.controller;

import com.zencode.jpa.jpaexample.entity.Customer;
import com.zencode.jpa.jpaexample.service.CustomerService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class CustomerController {
    
    @Autowired
    private CustomerService customerService;
    
    @GetMapping("/customers")
    public List<Customer> getAllCustomer() {
        return customerService.findAllCustomers();
    }
}

ลองเข้า http://localhost:8080/customes

ต่อไปเราจะมา Sort กัน เพิ่มเข้าไปครับ

package com.zencode.jpa.jpaexample.service;

import com.zencode.jpa.jpaexample.entity.Customer;
import com.zencode.jpa.jpaexample.repository.CustomerRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Sort;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;
import java.util.List;
import java.util.Random;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

@Service
public class CustomerService {

    @Autowired
    private CustomerRepository customerRepository;

    @PostConstruct
    public void InitData() {
        List<Customer> customerList = IntStream.range(1, 300)
                .mapToObj(i -> new Customer(i,"Customer " + i, new Random().nextInt(10000)))
                .collect(Collectors.toList());
        customerRepository.saveAll(customerList);
    }

    public List<Customer> findAllCustomers() {
       return customerRepository.findAll();
    }

    public List<Customer> findAllCustomersWithSorting(String field) {
        return customerRepository.findAll(Sort.by(Sort.Direction.DESC, field));
    }
}

จากโค้ด ก็คือเราจะเรียงจากมากไปหาน้อย ตาม field ที่ระบุไปใน Parameter

ต่อไปเรามาสร้าง Controller กันครับ

package com.zencode.jpa.jpaexample.controller;

import com.zencode.jpa.jpaexample.entity.Customer;
import com.zencode.jpa.jpaexample.service.CustomerService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class CustomerController {

    @Autowired
    private CustomerService customerService;

    @GetMapping("/customers")
    public List<Customer> getAllCustomer() {
        return customerService.findAllCustomers();
    }
    @GetMapping("/customers/sort_by/{field}")
    public List<Customer> getAllCustomerSortedByField(@PathVariable String field) {
        return customerService.findAllCustomersWithSorting(field);
    }
}

ลองเรียกดูครับ

• Sort by salary

• Sort by name ดูครับ

ว้าว ง่ายเนอะ ลองคิดดูถ้าเราใช้ JDBC Template จะเกิดอะไรขึ้น เขียนโค้ดกันสนานเลยงานนี้ ใช่ไหมครับ

ต่อไปเราจะมาสร้าง Pagination กันครับ

package com.zencode.jpa.jpaexample.service;

import com.zencode.jpa.jpaexample.entity.Customer;
import com.zencode.jpa.jpaexample.repository.CustomerRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Sort;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;
import java.util.List;
import java.util.Random;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

@Service
public class CustomerService {

    @Autowired
    private CustomerRepository customerRepository;

    @PostConstruct
    public void InitData() {
        List<Customer> customerList = IntStream.range(1, 300)
                .mapToObj(i -> new Customer(i,"Customer " + i, new Random().nextInt(10000)))
                .collect(Collectors.toList());
        customerRepository.saveAll(customerList);
    }

    public List<Customer> findAllCustomers() {
       return customerRepository.findAll();
    }

    public List<Customer> findAllCustomersWithSorting(String field) {
        return customerRepository.findAll(Sort.by(Sort.Direction.DESC, field));
    }

    public Page<Customer> findAllCustomersWithPagination(int offset, int pageSize) {
        return customerRepository.findAll(PageRequest.of(offset, pageSize));
    }
}

มาสร้าง Controller กัน

package com.zencode.jpa.jpaexample.controller;

import com.zencode.jpa.jpaexample.entity.Customer;
import com.zencode.jpa.jpaexample.service.CustomerService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class CustomerController {

    @Autowired
    private CustomerService customerService;

    @GetMapping("/customers")
    public List<Customer> getAllCustomer() {
        return customerService.findAllCustomers();
    }

    @GetMapping("/customers/sort_by/{field}")
    public List<Customer> getAllCustomerSortedByField(@PathVariable String field) {
        return customerService.findAllCustomersWithSorting(field);
    }

    @GetMapping("/customers/offset/{offset}/page-size/{pageSize}")
    public Page<Customer> getAllCustomerPagination(@PathVariable int offset, @PathVariable int pageSize) {
        return customerService.findAllCustomersWithPagination(offset, pageSize);
    }
}

ลองเรียกใช้ดูครับ

Response จะมีหน้าตาดังนี้

{
"content": [
{
"id": 1,
"name": "Customer 1",
"salary": 6958
},
{
"id": 2,
"name": "Customer 2",
"salary": 5873
},
{
"id": 3,
"name": "Customer 3",
"salary": 8287
},
{
"id": 4,
"name": "Customer 4",
"salary": 8425
},
{
"id": 5,
"name": "Customer 5",
"salary": 874
},
{
"id": 6,
"name": "Customer 6",
"salary": 1095
},
{
"id": 7,
"name": "Customer 7",
"salary": 1071
},
{
"id": 8,
"name": "Customer 8",
"salary": 3576
},
{
"id": 9,
"name": "Customer 9",
"salary": 8252
},
{
"id": 10,
"name": "Customer 10",
"salary": 9430
}
],
"pageable": {
"sort": {
"sorted": false,
"unsorted": true,
"empty": true
},
"pageNumber": 0,
"pageSize": 10,
"offset": 0,
"unpaged": false,
"paged": true
},
"totalPages": 30,
"totalElements": 299,
"last": false,
"first": true,
"numberOfElements": 10,
"size": 10,
"number": 0,
"sort": {
"sorted": false,
"unsorted": true,
"empty": true
},
"empty": false
}

โอ้วววว ง่ายดาย จิม จิม

เราก็สามารถใช้ Pagination ร่วมกัน Sort ได้นะครับ เช่น

package com.zencode.jpa.jpaexample.service;

import com.zencode.jpa.jpaexample.entity.Customer;
import com.zencode.jpa.jpaexample.repository.CustomerRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Sort;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;
import java.util.List;
import java.util.Random;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

@Service
public class CustomerService {

    @Autowired
    private CustomerRepository customerRepository;

    ........

    public Page<Customer> findAllCustomersWithPaginationSortBySalary(int offset, int pageSize) {
        return customerRepository.findAll(PageRequest.of(offset, pageSize, Sort.by("salary").descending()));
    }
}

เราสามารถทำ and , or ในการ Sort ได้นะครับ เช่น

public Page<Customer> findAllCustomersWithPaginationSortBySalary(int offset, int pageSize) {
    return customerRepository.findAll(PageRequest.of(offset, pageSize, Sort.by("salary").descending().and(Sort.by("name").ascending())));
}

Controller เพิ่มแบบนี้ครับ

package com.zencode.jpa.jpaexample.controller;

import com.zencode.jpa.jpaexample.entity.Customer;
import com.zencode.jpa.jpaexample.service.CustomerService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
public class CustomerController {

    @Autowired
    private CustomerService customerService;

   .......

    @GetMapping("/sorted-salary-customers/offset/{offset}/page-size/{pageSize}")
    public Page<Customer> getAllCustomersWithPaginationSortBySalary(@PathVariable int offset, @PathVariable int pageSize) {
        return customerService.findAllCustomersWithPaginationSortBySalary(offset, pageSize);
    }
}

ลองเรียกดูครับ

Response

{
"content": [
{
"id": 13,
"name": "Customer 13",
"salary": 9978
},
{
"id": 152,
"name": "Customer 152",
"salary": 9899
},
{
"id": 205,
"name": "Customer 205",
"salary": 9857
},
{
"id": 155,
"name": "Customer 155",
"salary": 9834
},
{
"id": 167,
"name": "Customer 167",
"salary": 9796
},
{
"id": 29,
"name": "Customer 29",
"salary": 9703
},
{
"id": 75,
"name": "Customer 75",
"salary": 9658
},
{
"id": 56,
"name": "Customer 56",
"salary": 9631
},
{
"id": 231,
"name": "Customer 231",
"salary": 9622
},
{
"id": 194,
"name": "Customer 194",
"salary": 9579
}
],
"pageable": {
"sort": {
"unsorted": false,
"sorted": true,
"empty": false
},
"pageNumber": 0,
"pageSize": 10,
"offset": 0,
"unpaged": false,
"paged": true
},
"totalPages": 30,
"totalElements": 299,
"last": false,
"numberOfElements": 10,
"first": true,
"sort": {
"unsorted": false,
"sorted": true,
"empty": false
},
"size": 10,
"number": 0,
"empty": false
}

ลองไปหัดใช้กันให้คล่องนะครับ