Getting Started with Spring Data MongoDB using Java Configuration

In this tutorial, I’ll show you how to use Spring Data MongoDB to integrate a MongoDB NoSQL database into a Spring Boot application.

Spring Data MongoDB using Java Configuration - Thomas Vitale

I’ll use these technologies and tools:

  • Spring Tool Suite (STS) 3.8.4.RELEASE
  • Java 8
  • Spring Boot 1.5.3.RELEASE
  • Maven 3.3.9
  • MongoDB 3.3.4

1. The Project Structure

The final folder structure of our project.

The project structure of our Spring Data MongoDB Project as seen in STS

2. Create a new Spring Boot project

If you’re using STS, you can create a starter project by either selecting File > New > Spring Starter Project from the main menu or right-click on the Package Explorer and choose New > Spring Starter Project.

STS command to create a new Spring Starter Project

STS dialog window for Spring Starter Project

STS dialog window for Spring Boot Starter with Data MongoDB

In case you’re using another IDE like Eclipse, Netbeans or IntelliJ IDEA, you can create a new Maven project and add to the pom.xml file the dependencies listed in the next paragraph.

3. Maven Dependencies

spring-boot-starter-data-mongodb is the primary dependency of our 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>
<groupId>com.thomasvitale</groupId>
<artifactId>Application</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>Application</name>
<description>Demo application for Spring Data MongoDB</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.3.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>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-mongodb</artifactId>
</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>
view raw pom.xml hosted with ❤ by GitHub

4. Spring Configuration using Java Annotations

Spring lets you use either Java configuration or XML configuration or a mix of the two. I’ll use a pure Java configuration and store MongoDB properties in a dedicated file.

@Configuration
@EnableMongoRepositories(basePackages = "com.thomasvitale.repository")
@PropertySource("classpath:mongo.properties")
public class MongoConfig extends AbstractMongoConfiguration {
@Autowired
private Environment env;
@Override
protected String getDatabaseName() {
return env.getProperty("mongo.database");
}
@Override
public Mongo mongo() throws Exception {
return new MongoClient(env.getProperty("mongo.host"), Integer.parseInt(env.getProperty("mongo.port")));
}
@Override
protected String getMappingBasePackage() {
return "com.thomasvitale.model";
}
}
view raw MongoConfig.java hosted with ❤ by GitHub
mongo.database=mydb
mongo.host=127.0.0.1
mongo.port=32769
view raw mongo.properties hosted with ❤ by GitHub

5. Person Model

The following is the Person Model. The @Document(collection = "persons") annotation specifies in which collection to store a Person document.

@Document(collection = "persons")
public class Person {
@Id
private String id;
private String firstName;
private String lastName;
public Person() {
}
public Person(String firstName, String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
@Override
public String toString() {
return firstName + " " + lastName;
}
}
view raw Person.java hosted with ❤ by GitHub

6. Person Repository

By extending MongoRepository, our PersonRepository has a lot of available operations, including the standard CRUD operations. You can also add custom operations like findByFirstName and findByLastName without writing any implementation: Spring Data MongoDB creates them for you!

public interface PersonRepository extends MongoRepository<Person, String> {
public Person findByFirstName(String firstName);
public List<Person> findByLastName(String lastName);
}

7. Demo

Since we have Spring Data MongoDB configured, a model and a repository, it’s time to test the application by performing some CRUD and custom operations.

@SpringBootApplication
public class Application implements CommandLineRunner {
@Autowired
PersonRepository personRepository;
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
@Override
public void run(String... arg0) throws Exception {
// Save two Person documents on Mongo
personRepository.save(new Person("Sheldon", "Cooper"));
personRepository.save(new Person("Missy", "Cooper"));
personRepository.save(new Person("Leonard", "Hofstadter"));
// Get all people
System.out.println(">>> All people in the database:");
personRepository.findAll().forEach(System.out::println);
// Get all people with a specific last name
System.out.println(">>> All people with last name = 'Cooper'");
personRepository.findByLastName("Cooper").forEach(System.out::println);
// Update an individual person
Person person = personRepository.findByFirstName("Sheldon");
person.setFirstName("Shelly");
personRepository.save(person);
// Delete all
personRepository.deleteAll();
}
}
view raw Application.java hosted with ❤ by GitHub

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