Access NoSQL databases with CDI

You can create a CDI producer to provide access to a NoSQL database, such as MongoDB or CouchDB. With a CDI producer, you are not restricted to certain versions of NoSQL databases to provide a database for your application.

You can modify a CDI producer according to your needs. For example, you can add authentication or enable Transport Layer Security (TLS) for your database connection. You can also use MicroProfile Config to configure the database driver. Using a CDI producer eliminates the need to enable features like the MongoDB Integration feature for MongoDB or the CouchDB Integration feature for CouchDB. The MongoDB Integration feature is stabilized in Open Liberty 19.0.0.4 and later. The CouchDB Integration feature is stabilized in Open Liberty 19.0.0.6 and later.

Access MongoDB with CDI

To use CDI with Open Liberty, enable the Contexts and Dependency Injection feature. You can configure access to any version of MongoDB with a CDI producer. This example demonstrates how to create a CDI producer to inject a MongoDatabase instance in your application:

@ApplicationScoped
public class MongoProducer {

    @Produces
    public MongoClient createMongo() {
        return new MongoClient(new ServerAddress(), new MongoClientOptions.Builder().build());
    }

    @Produces
    public MongoDatabase createDB(MongoClient client) {
        return client.getDatabase("testdb");
    }

    public void close(@Disposes MongoClient toClose) {
        toClose.close();
    }
}

The createMongo()producer method returns a MongoClient instance. The createDB()producer method returns a MongoDatabase instance that depends on the MongoClient instance. The close() method is a clean-up function for the MongoClient instance that closes the connection to the MongoDatabase instance. You can use the CDI producer that you created to inject a MongoDatabase instance into the application, as shown in the following example:

@Inject
MongoDatabase db;

@POST
@Path("/add")
@Consumes(MediaType.APPLICATION_JSON)
public void add(CrewMember crewMember) {
    MongoCollection<Document> crew = db.getCollection("Crew");
    Document newCrewMember = new Document();
    newCrewMember.put("Name",crewMember.getName());
    crew.insertOne(newCrewMember);
}

Secure your CDI producer

Enable the Password Utilities feature in the server.xml file to include authentication in your CDI producer. In the following example, the CDI producer is enhanced to provide a username and an encoded password for the database connection.

@Produces
public MongoClient createMongo() {
    String password = PasswordUtil.passwordDecode(encodedPass);
    MongoCredential creds = MongoCredential.createCredential(user, dbName, password.toCharArray());
    return new MongoClient(new ServerAddress(), creds, new MongoClientOptions.Builder().build());
}

To enable TLS for your CDI producer, first configure TLS for your Open Liberty server. Then, modify your CDI producer to add the JSSEHelper class to the createMongo method and get the SSLContext class, as shown in the following example:

@Produces
public MongoClient createMongo() throws SSLException {
    String password = PasswordUtil.passwordDecode(encodedPass);
    MongoCredential creds = MongoCredential.createCredential(user, dbName, password.toCharArray());
    SSLContext sslContext = JSSEHelper.getInstance().getSSLContext("defaultSSLConfig", Collections.emptyMap(), null);
    return new MongoClient(new ServerAddress(hostname, port), creds, new MongoClientOptions.Builder()
                           .sslEnabled(true)
                           .sslContext(sslContext)
                           .build());
}

Configure MongoDB with MicroProfile Config

To configure the MongoDB driver with MicroProfile Config, enable the MicroProfile Config feature in the server.xml file. Then, add the following code to your CDI producer:

@Inject
@ConfigProperty(name = "mongo.hostname", defaultValue = "localhost")
String hostname;

@Inject
@ConfigProperty(name = "mongo.port", defaultValue = "27017")
int port;

@Inject
@ConfigProperty(name = "mongo.dbname", defaultValue = "testdb")
String dbName;

@Inject
@ConfigProperty(name = "mongo.user")
String user;

@Inject
@ConfigProperty(name = "mongo.pass.encoded")
String encodedPass;

Add the following snippet to your microprofile-config.properties or server.env file to pull the values for the username and encoded password into the MongoProducer class:

mongo.user=sampleUser
mongo.pass.encoded={aes}APtt+/vYxxPa0jE1rhmZue9wBm3JGqFK3JR4oJdSDGWM1wLr1ckvqkqKjSB2Voty8g==

Access CouchDB with CDI

You can configure access to any version of CouchDB with a CDI producer in Open Liberty. To access CouchDB with CDI, you can replace the MongoClient in the previous examples with any CouchDB client or use the Cloudant service, which is based on CouchDB.

See also

Guide: Persisting data with MongoDB

Blog: Access any version of MongoDB with Open Liberty using CDI