Hey guys in this post we will discuss and implement Sorting
multiple columns in Data JPA with examples.
Table of Contents
Overview
Data JPA provides Sorting
option out of the box. To add Sorting
option to our Repositories, we need to extend the PagingAndSortingRepository<T, ID>
interface rather than the basic CrudRepository<T, ID>
interface.
By extending the repository PagingAndSortingRepository<T, ID>
, we get the following method –
List<Laptop> findAll(Sort sort);
Returns a sorted list of laptops.
Even we can use JPARepository<T, ID>
instead, which extends the PagingAndSortingRepository<T, ID>
Once we extend the repository, we just need to create the Sort
object which provides the following static method –
Sort sort = Sort.by(Direction direction, String... properties);
Creates a new Sort
for the given Sort.Direction
and the name of the property on which we need to sort. To sort multiple columns, we need to pass the multiple column names with comma-separated.
Sort sort = Sort.by(Direction.DESC, field1, field2)
Here first, it will sort based on field1
, and then it will sort based on field2
. On both properties, it will sort on Descending
order.
what if we want to sort each property in a different direction?
We can do that with the help of the Order
class, which is the inner class of the Sort
class.
Order order = new Order(Direction.DESC, field1);
Creates a new Sort.Order
instance. if the order is null then the order defaults to Sort.DEFAULT_DIRECTION
Usage of Interfaces, Classes, and Methods
PagingAndSortingRepository<T, ID>
: Extension ofCrudRepository<T, ID>
to provide additional methods to retrieve entities using the pagination and sorting abstraction.Sort
: Sort option for queries. You have to provide at least a list of properties to sort for that must not include null or empty strings. The direction defaults toDEFAULT_DIRECTION
.Sort.DIRECTION
: Enumeration for sort directions.by()
: Creates a newSort
for the givenSort.Direction
.Order
: PropertyPath implements the pairing of anSort.Direction
and a property. It is used to provide input forSort
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.ArrayList;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Sort;
import org.springframework.data.domain.Sort.Direction;
import org.springframework.data.domain.Sort.Order;
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("/laptopsByCols")
public List<Laptop> getAllByCols (@RequestParam String field1, @RequestParam String field2) {
return lRepo.findAll(Sort.by(Direction.DESC, field1, field2));
}
@GetMapping("/laptopsByDirections")
public List<Laptop> getAllByDirections (@RequestParam String field1, @RequestParam String field2) {
List<Order> orders = new ArrayList<>();
orders.add(new Order(Direction.DESC, field1));
orders.add(new Order(Direction.ASC, field2));
return lRepo.findAll(Sort.by(orders));
}
}
Here we have created 2 handler methods, getAllByCols()
and getAllByDirections()
. The first handler method will sort the multiple columns in the same direction. The second handler method will sort the multiple columns in different directions.
Run the app
Run the application using the below maven command –
mvn spring-boot:run
Open the browser and enter the following URL –
localhost:8080/laptopsByCols?field1=brand&field=price
[
{
"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"
},
{
"id": 2,
"name": "Dell XPS",
"description": "dell company laptop",
"brand": "Dell",
"price": 70000.0,
"date": "2020-12-31"
},
{
"id": 1,
"name": "Dell Inspiron",
"description": "dell company laptop",
"brand": "Dell",
"price": 60000.0,
"date": "2021-02-10"
},
{
"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/laptopsByDirections?field1=brand&field=price
[
{
"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"
},
{
"id": 1,
"name": "Dell Inspiron",
"description": "dell company laptop",
"brand": "Dell",
"price": 60000.0,
"date": "2021-02-10"
},
{
"id": 2,
"name": "Dell XPS",
"description": "dell company laptop",
"brand": "Dell",
"price": 70000.0,
"date": "2020-12-31"
},
{
"id": 3,
"name": "Macbook Air",
"description": "apple company laptop",
"brand": "Apple",
"price": 85000.0,
"date": "2021-01-31"
},
{
"id": 4,
"name": "Macbook Pro",
"description": "apple company laptop",
"brand": "Apple",
"price": 160000.0,
"date": "2021-12-25"
}
]