Spring Boot connect Mysql and MongoDb

Question

I have a problem with Spring Boot application. I want to connect a MongoDB database and a MySql database in my Spring boot application. I would to know if it is possible, in positive case How I can make this multiple connection. I had made a try based on an example with Mysql and Post without success. So I'm wondering if someone have an easy example to know the method. thanks

Answer 1

You really don't need to make additional config and property files because MongoDB has different property names than sql so all you will need is an application.properties file

application.properties

spring.datasource.url=jdbc:mysql://${MYSQL_HOST:localhost}:3306/dbName?useUnicode=yes&characterEncoding=UTF-8
spring.datasource.username=root
spring.datasource.password=

spring.data.mongodb.uri=mongodb://localhost:27017
spring.data.mongodb.database=dbName

example models

MongoDB document

import org.springframework.data.mongodb.core.mapping.Document;
import javax.persistence.Id;

    @Document("Gyros")
    public class Gyros {
    
        public Gyros(String description) {
            this.description = description;
        }
    
        @Id
        public String id;
    
        public String description;
    }

Mysql JPA entity

import javax.persistence.*;

@Entity
@Table(name = "Kebab")
public class Kebab {

    public Kebab(String description) {
        this.description = description;
    }

    public Kebab() {
    }

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

    public String description;
}

MongoDB repository

@Repository
public interface GyrosRepository extends MongoRepository<Gyros, String> {
}

Mysql Jpa repository

    @Repository
    public interface KebabRepository extends JpaRepository<Kebab, Integer> {
    }

TestService

@org.springframework.stereotype.Service
public class Service {

    private final GyrosRepository gyrosRepository;
    private final KebabRepository kebabRepository;

    @Autowired
    public Service(GyrosRepository gyrosRepository, KebabRepository kebabRepository) {
        this.gyrosRepository = gyrosRepository;
        this.kebabRepository = kebabRepository;
    }

    @PostConstruct
    void test() {
        this.gyrosRepository.insert(new Gyros("ham ham"));
        this.kebabRepository.saveAndFlush(new Kebab("yum yum"));
    }
}

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>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <groupId>org.example</groupId>
    <artifactId>stack</artifactId>
    <version>1.0-SNAPSHOT</version>
    <name>stackoverflow</name>

    <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-data-mongodb</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
    </dependencies>

</project>