Hey guys in this post we will discuss Data JPA Sorting and Pagination with examples in Spring Boot.
We have already discussed Soring and Pagination separately, you can follow the below articles to read more about them.
>> Spring Boot Data JPA Pagination with Example
>> Spring Boot Data JPA Sorting with Example
Table of Contents
Complete example
Let’s create a step-by-step spring boot project and create different finder methods for various fields.
Create database and insert sample data
Open MySQL workbench and execute the following commands
CREATE DATABASE mydb;
USE mydb;
CREATE TABLE tbl_laptops(
id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
name VARCHAR(255) NOT NULL,
description VARCHAR(255) NOT NULL,
brand VARCHAR(255) NOT NULL,
price DOUBLE(10, 2) NOT NULL,
created_at DATE NOT NULL
);
INSERT INTO tbl_laptops(name, description, brand, price, created_at)
VALUES("Dell Inspiron", "dell company laptop", "Dell", 60000.00, '2021-02-10');
INSERT INTO tbl_laptops(name, description, brand, price, created_at)
VALUES("Dell XPS", "dell company laptop", "Dell", 70000.00, '2020-12-31');
INSERT INTO tbl_laptops(name, description, brand, price, created_at)
VALUES("Macbook Air", "apple company laptop", "Apple", 85000.00, '2021-01-31');
INSERT INTO tbl_laptops(name, description, brand, price, created_at)
VALUES("Macbook Pro", "apple company laptop", "Apple", 160000.00, '2021-12-25');
INSERT INTO tbl_laptops(name, description, brand, price, created_at)
VALUES("HP", "hp company laptop", "HP", 50000.00, '2021-02-10');
INSERT INTO tbl_laptops(name, description, brand, price, created_at)
VALUES("Lenovo", "lenovo company laptop", "Lenovo", 50000.00, '2020-11-21');
SELECT * FROM tbl_laptops;
We have created a table tbl_laptops that contains 5 fields. We have inserted the sample data as well.
Create spring boot project
There are many different ways to create a spring boot application, you can follow the below articles to create one –
>> Create spring boot application using Spring initializer
>> Create spring boot application in Spring tool suite [STS]
>> Create spring boot application in IntelliJ IDEA
Add maven dependencies
Open pom.xml and add the following dependencies –
<?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>2.4.4</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>in.bushansirgur</groupId>
<artifactId>findbyfieldname</artifactId>
<version>v1</version>
<name>findbyfieldname</name>
<description>Spring boot data jpa find by field name</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>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</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>
spring-boot-starter-web dependency for building web applications using Spring MVC. It uses the tomcat as the default embedded container.
spring-boot-devtools dependency for automatic reloads or live reload of applications. spring-boot-starter-data-jpa dependency is a starter for using Spring Data JPA with Hibernate. lombok dependency is a java library that will reduce the boilerplate code that we usually write inside every entity class like setters, getters, and toString()
Create an entity class
Create Laptop.java inside the in.bushansirgur.springboot.entity package and add the following content
package in.bushansirgur.springboot.entity;
import java.math.BigDecimal;
import java.sql.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;
import lombok.Data;
@Entity
@Table(name="tbl_laptops")
@Data
public class Laptop {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Long id;
private String name;
private String brand;
private String description;
private BigDecimal price;
@Column(name="created_at")
private Date createdAt;
}
We have added @Data annotation which is a Lombok annotation, that will automatically create setters, getters, toString(), and equals() for us.
@Entity is a mandatory annotation that indicates that this class is a JPA entity and is mapped with a database table.
@Table annotation is an optional annotation that contains the table info like table name.
@Id annotation is a mandatory annotation that marks a field as the primary key
Create a Repository
Create an interface LaptopRepository.java inside the in.bushansirgur.springboot.repos package and add the following content
package in.bushansirgur.springboot.repos; import java.math.BigDecimal; import java.util.List; import java.sql.Date; import org.springframework.data.jpa.repository.JpaRepository; import org.springframework.stereotype.Repository; import in.bushansirgur.springboot.entity.Laptop; @Repository public interface LaptopRepository extends JpaRepository<Laptop, Long> { }
Create a Rest controller
Create LaptopController.java inside the in.bushansirgur.springboot.controller package and add the following content
package in.bushansirgur.springboot.controller;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.PageRequest;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort.Direction;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
import in.bushansirgur.springboot.entity.Laptop;
import in.bushansirgur.springboot.repos.LaptopRepository;
@RestController
public class LaptopController {
@Autowired
LaptopRepository lRepo;
@GetMapping("/laptops")
public List<Laptop> getAll (@RequestParam String field, @RequestParam int page, @RequestParam int size) {
Pageable pageable = PageRequest.of(page, size, Direction.DESC, field);
return lRepo.findAll(pageable).toList();
}
}
We have created a handler method getAll() which will accept 3 request params field, page and size.
The field contains the name of the property which we need to sort by, page contains the page number, size contains the number of records on each page.
We will make use of PageRequest.of() method to create the Pageable object, and we will convert it to List<Laptop> by calling toList() method on the Pageable object.
Run the app
Run the application using the below maven command –
mvn spring-boot:runOpen the browser and enter the following URL –
localhost:8080/laptops?field=name&page=0&size=2
[
{
"id": 4,
"name": "Macbook Pro",
"description": "apple company laptop",
"brand": "Apple",
"price": 160000.0,
"date": "2021-12-25"
},
{
"id": 3,
"name": "Macbook Air",
"description": "apple company laptop",
"brand": "Apple",
"price": 85000.0,
"date": "2021-01-31"
}
]
localhost:8080/laptops?field=name&page=1&size=2
[
{
"id": 6,
"name": "Lenovo",
"description": "lenovo company laptop",
"brand": "Lenovo",
"price": 50000.0,
"date": "2020-11-21"
},
{
"id": 5,
"name": "HP",
"description": "hp company laptop",
"brand": "HP",
"price": 50000.0,
"date": "2021-02-10"
}
]
