In this example, we will create a Spring boot Hibernate application to demonstrate how to manually assigning UUID identifiers.

Spring Boot Hibernate Assign UUID Identifiers Example

This application is an example of manually assigning UUID identifiers.

1. Create a Spring Boot Application

Use Spring initializr to quickly create Spring boot application:

https://start.spring.io/

2. Maven configuration - pom.xml

<?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>
    <groupId>com.jpa</groupId>
    <artifactId>HibernateSpringBootAssignedUUID</artifactId>
    <version>1.0</version>
    <packaging>jar</packaging>
    <name>HibernateSpringBootAssignedUUID</name>
    <description>JPA project for Spring Boot</description>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/>
        <!-- lookup parent from repository -->
    </parent>
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>12</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-jdbc</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </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>
</project>

3. Configure MySQL Database - application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/demo?createDatabaseIfNotExist=true
spring.datasource.username=root
spring.datasource.password=root

spring.jpa.hibernate.ddl-auto=create
spring.jpa.show-sql=true

spring.jpa.properties.hibernate.dialect=org.hibernate.dialect.MySQL8Dialect

spring.jpa.open-in-view=false

logging.level.org.hibernate.type.descriptor.sql=TRACE

Create JPA Entity - Author.java

import java.io.Serializable;
import java.util.UUID;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;

@Entity
public class Author implements Serializable {

    private static final long serialVersionUID = 1L;

    @Id
    @Column(columnDefinition = "BINARY(16)")
    private UUID id;

    private int age;
    private String name;
    private String genre;

    public UUID getId() {
        return id;
    }

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

    public String getName() {
        return name;
    }

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

    public String getGenre() {
        return genre;
    }

    public void setGenre(String genre) {
        this.genre = genre;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Author{" + "id=" + id + ", age=" + age
                + ", name=" + name + ", genre=" + genre + '}';
    }
}

Note that we store UUID in a BINARY(16) column:

    @Id
    @Column(columnDefinition = "BINARY(16)")
    private UUID id;

Create JPA Repository - AuthorRepository.java

import com.example.entity.Author;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.stereotype.Repository;

@Repository
public interface AuthorRepository extends JpaRepository<Author, Long> {
}

Create Service - AuthorService.java

import com.example.entity.Author;
import com.example.repository.AuthorRepository;
import java.util.UUID;
import org.springframework.stereotype.Service;

@Service
public class BookstoreService {

    private final AuthorRepository authorRepository;

    public BookstoreService(AuthorRepository authorRepository) {
        this.authorRepository = authorRepository;
    }

    public void insertAuthor() {
        Author author = new Author();
        author.setId(UUID.randomUUID());
        author.setName("Admin");
        author.setGenre("History");
        author.setAge(34);

        authorRepository.save(author);
    }
}

Note that we manually assign the UUID value (for example, via UUID.randomUUID() ):

        Author author = new Author();
        author.setId(UUID.randomUUID());

Test

Let's run Spring boot main class to test this example:

import com.bookstore.service.BookstoreService;
import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;

@SpringBootApplication
public class MainApplication {

    private final BookstoreService bookstoreService;

    public MainApplication(BookstoreService bookstoreService) {
        this.bookstoreService = bookstoreService;
    }

    public static void main(String[] args) {
        SpringApplication.run(MainApplication.class, args);
    }

    @Bean
    public ApplicationRunner init() {
        return args - > {
            bookstoreService.insertAuthor();
        };
    }
}