Conditions in Custom Query in Spring Boot JPA

On the Eclipse, create a Spring Boot project

Enter Project Information:

  • Name: SpringBootDataJPA
  • Group: com.demo
  • Artifact: SpringBootDataJPA
  • Description: Spring Boot Data JPA
  • Package: com.demo

Select the technologies and libraries to be used:

  • JPA
  • MySQL

Click Next button to show Site Information for project

Click Finish button to finish create Spring Boot project




<?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 http://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>2.2.0.M1</version>
		<relativePath /> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.demo</groupId>
	<artifactId>SpringBootDataJPA</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>SpringBootDataJPA</name>
	<description>Spring Boot Data JPA</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>mysql</groupId>
			<artifactId>mysql-connector-java</artifactId>
			<scope>runtime</scope>
		</dependency>

		<dependency>
			<groupId>net.bytebuddy</groupId>
			<artifactId>byte-buddy</artifactId>
			<version>1.9.12</version>
		</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>
			</plugin>
		</plugins>
	</build>

	<repositories>
		<repository>
			<id>spring-snapshots</id>
			<name>Spring Snapshots</name>
			<url>https://repo.spring.io/snapshot</url>
			<snapshots>
				<enabled>true</enabled>
			</snapshots>
		</repository>
		<repository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
		</repository>
	</repositories>
	<pluginRepositories>
		<pluginRepository>
			<id>spring-snapshots</id>
			<name>Spring Snapshots</name>
			<url>https://repo.spring.io/snapshot</url>
			<snapshots>
				<enabled>true</enabled>
			</snapshots>
		</pluginRepository>
		<pluginRepository>
			<id>spring-milestones</id>
			<name>Spring Milestones</name>
			<url>https://repo.spring.io/milestone</url>
		</pluginRepository>
	</pluginRepositories>

</project>




Create a database with the name is springbootdatajpa. This database have a table: Product

--
-- Table structure for table `product`
--

CREATE TABLE `product` (
  `id` int(11) NOT NULL PRIMARY KEY AUTO_INCREMENT,
  `name` varchar(250) COLLATE utf8_unicode_ci NOT NULL,
  `price` decimal(10,1) NOT NULL,
  `quantity` int(11) NOT NULL,
  `description` text COLLATE utf8_unicode_ci NOT NULL,
  `photo` varchar(250) COLLATE utf8_unicode_ci NOT NULL,
  `featured` tinyint(1) NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

--
-- Dumping data for table `product`
--

INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `photo`, `featured`) VALUES('Mobile 1', '2.0', 2, 'description 1', 'thumb1.gif', 0);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `photo`, `featured`) VALUES('Mobile 2', '1.0', 5, 'description 2', 'thumb2.gif', 1);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `photo`, `featured`) VALUES('Mobile 3', '3.0', 9, 'description 3', 'thumb3.gif', 0);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `photo`, `featured`) VALUES('Computer 1', '5.0', 12, 'description 4', 'thumb1.gif', 1);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `photo`, `featured`) VALUES('Computer 2', '7.0', 5, 'description 5', 'thumb1.gif', 0);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `photo`, `featured`) VALUES('Computer 3', '12.0', 2, 'description 6', 'thumb2.gif', 1);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `photo`, `featured`) VALUES('Laptop 1', '3.0', 8, 'description 7', 'thumb2.gif', 0);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `photo`, `featured`) VALUES('Laptop 2', '4.0', 11, 'description 8', 'thumb3.gif', 1);
INSERT INTO `product` (`name`, `price`, `quantity`, `description`, `photo`, `featured`) VALUES('Laptop 3', '2.0', 15, 'description 9', 'thumb2.gif', 0);




Open application.properties file in src/main/resources folder and add configurations connect to database as below:

spring.datasource.url= jdbc:mysql://localhost:3306/springbootdatajpa
spring.datasource.username=root
spring.datasource.password=123456

Create new package named com.demo.entities. In this package, create new java class named Product.java as below:

package com.demo.entities;

import java.io.Serializable;

import java.math.BigDecimal;

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

@Entity
@Table(name = "product")
public class Product implements Serializable {
	private static final long serialVersionUID = 1L;

	@Id
	@GeneratedValue(strategy = GenerationType.IDENTITY)
	private int id;

	private String name;

	private BigDecimal price;

	private int quantity;

	private String description;

	private String photo;

	private boolean featured;

	public int getId() {
		return id;
	}

	public void setId(int id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public BigDecimal getPrice() {
		return price;
	}

	public void setPrice(BigDecimal price) {
		this.price = price;
	}

	public int getQuantity() {
		return quantity;
	}

	public void setQuantity(int quantity) {
		this.quantity = quantity;
	}

	public String getDescription() {
		return description;
	}

	public void setDescription(String description) {
		this.description = description;
	}

	public String getPhoto() {
		return photo;
	}

	public void setPhoto(String photo) {
		this.photo = photo;
	}

	public boolean isFeatured() {
		return featured;
	}

	public void setFeatured(boolean featured) {
		this.featured = featured;
	}

}




Create new package named com.demo.repositories. In this package, create new interface named ProductRepository.java implement from CrudRepository interface of Spring Framework as below:

package com.demo.repositories;

import java.math.BigDecimal;
import java.util.List;
import org.springframework.data.jpa.repository.Query;
import org.springframework.data.repository.CrudRepository;
import org.springframework.data.repository.query.Param;
import org.springframework.stereotype.Repository;
import com.demo.entities.Product;

@Repository("productRepository")
public interface ProductRepository extends CrudRepository<Product, Integer> {

	@Query("from Product where price >= :min")
	public List<Product> findByPrice(@Param("min") BigDecimal min);

}

Create new package named com.demo.services. In this package create new interface named ProductService.java as below:

package com.demo.services;

import java.math.BigDecimal;
import java.util.List;
import com.demo.entities.Product;

public interface ProductService {

	public List<Product> findByPrice(BigDecimal min);

}

In com.demo.services package, create new java class named ProductServiceImpl.java implement from ProductService interface

package com.demo.services;

import java.math.BigDecimal;
import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import com.demo.entities.Product;
import com.demo.repositories.ProductRepository;

@Transactional
@Service("productService")
public class ProductServiceImpl implements ProductService {

	@Autowired
	private ProductRepository productRepository;

	@Override
	public List<Product> findByPrice(BigDecimal min) {
		return productRepository.findByPrice(min);
	}

}




In com.demo package, create new java class named JPAConfiguration.java as below:

package com.demo;

import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.PropertySource;
import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
import org.springframework.transaction.annotation.EnableTransactionManagement;

import com.demo.services.ProductService;
import com.demo.services.ProductServiceImpl;

@Configuration
@EnableAutoConfiguration
@EnableTransactionManagement
@EnableJpaRepositories(basePackages = { "com.demo.repositories" })
@ComponentScan("com.demo")
@PropertySource("classpath:application.properties")
public class JPAConfiguration {

	@Bean
	public ProductService productService() {
		return new ProductServiceImpl();
	}

}




Create new package named com.demo.main. In this package, create new java file named Demo.java as below:

package com.demo.main;

import java.math.BigDecimal;

import org.springframework.context.annotation.AnnotationConfigApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;

import com.demo.entities.Product;
import com.demo.JPAConfiguration;
import com.demo.services.ProductService;

public class Demo {

	public static void main(String[] args) {
		try {
			AbstractApplicationContext context = new AnnotationConfigApplicationContext(JPAConfiguration.class);
			ProductService productService = context.getBean(ProductService.class);

			for(Product product : productService.findByPrice(BigDecimal.valueOf(5))) {
				System.out.println("Id: " + product.getId());
				System.out.println("Name: " + product.getName());
				System.out.println("Price: " + product.getPrice());
				System.out.println("========================");
			}

			context.close();
		} catch (Exception e) {
			System.out.println(e.getMessage());
		}
	}

}
Id: 4
Name: Computer 1
Price: 5.0
========================
Id: 5
Name: Computer 2
Price: 7.0
========================
Id: 6
Name: Computer 3
Price: 12.0
========================