Using Spring Data Mongo with Spring's Java Configuration (JavaConfig) style with Maven, JUnit, Log4J

In this example I am going to show you how to post data to a MongoDB database using Spring Data Mongo in Java using Spring, Spring Java Configuration, Maven and Log4J.

Spring Java Configuration

Let's take a quick look at the Spring Java Configuration file that the project is going to be using

@Configuration
@EnableMongoRepositories
@ComponentScan(basePackageClasses = {MongoDBApp.class})
@PropertySource("classpath:application.properties")
public class MongoConfiguration extends AbstractMongoConfiguration
{


    @Override
    protected String getDatabaseName() {
        return "demo";
    }

    @Override
    public Mongo mongo() throws Exception {
        return new Mongo();
    }

    @Override
    protected String getMappingBasePackage() {
        return "com.johnathanmarksmith.mongodb.example.domain";
    }

}

As you can see from the above code the trick to all this is to use @EnableMongoRepositories and to extend your class from AbstractMongoConfiguration.

The Person Object

Now we are going to take a look at the object that we are going to be inserting into the database.

    @Document
    public class Person {

    @Id
    private String personId;

    private String name;
    private int age;

    public Person(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getPersonId() {
        return personId;
    }

    public void setPersonId(final String personId) {
        this.personId = personId;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(final int age) {
        this.age = age;
    }
    @Override
    public String toString() {
        return "Person [id=" + personId + ", name=" + name
                + ", age=" + age +  "]";
    }

}

You see we use the @Document and the @Id.

The Repository

Now its time to see the source code in the repository

@Repository
public class PersonRepository {

    static final Logger logger = LoggerFactory.getLogger(PersonRepository.class);

    @Autowired
    MongoTemplate mongoTemplate;

    public void countUnderAge() {
        List<Person> results = null;

        Query query = new Query();
        Criteria criteria = new Criteria();
        criteria = criteria.and("age").lte(21);

        query.addCriteria(criteria);
        results = mongoTemplate.find(query, Person.class);

        logger.info("Total number of under age in database: {}", results.size());
    }

    /**
     * This will count how many Person Objects I have
     */
    public void countAllPersons() {
        List<Person> results = mongoTemplate.findAll(Person.class);
        logger.info("Total number in database: {}", results.size());
    }

    /**
     * This will install a new Person object with my
     * name and random age
     */
    public void insertPersonWithNameJohnathanAndRandomAge() {

        double age = Math.ceil(Math.random() * 100);
        Person p = new Person("Johnathan", (int) age);

        mongoTemplate.insert(p);
    }

    /**
     * this will create a {@link Person} collection if the collection does not already exists
     */
    public void createPersonCollection() {
        if (!mongoTemplate.collectionExists(Person.class)) {
            mongoTemplate.createCollection(Person.class);
        }
    }

    /**
     * this will drop the {@link Person} collection if the collection does already exists
     */
    public void dropPersonCollection() {
        if (mongoTemplate.collectionExists(Person.class)) {
            mongoTemplate.dropCollection(Person.class);
        }
    }
}

The Main Class

Time for the main class now.. are you ready for all this code??

    public static void main(String[] args) {
        logger.info("MongoDemo application");

        ApplicationContext context = new AnnotationConfigApplicationContext(MongoConfiguration.class);

        PersonRepository personRepository = context.getBean(PersonRepository.class);

        // cleanup person collection before insertion
        personRepository.dropPersonCollection();

        //create person collection
        personRepository.createPersonCollection();



        for (int i = 0; i < 10000; i++) {
            personRepository.insertPersonWithNameJohnathanAndRandomAge();
        }

        personRepository.countAllPersons();


        /***
         *
         * Added Under Age Test For someone to see
         *
         */
        personRepository.countUnderAge();


        logger.info("MongoDemo application");
    }
}

You can see from the above code how easy it is to use Spring Data Mongo to post data to a MongoDB.

Download and Run

You can checkout the project from github.

git clone [email protected]:JohnathanMarkSmith/spring-mongo-demo.git
cd spring-mongo-demo
mvn clean package
mvn exec:java

Please keep in mind to be able to run this demo application start your MongoDB instance, Yes you need MongoDB.

If you have any questions please email me at [email protected]

For a MongoDB guide see http://www.mongodb.org/display/DOCS/Quickstart

Thanks, Johnathan Mark Smith