Question

We’re working on deploying a Java project to Heroku that uses MongoDB. According to the Heroku docs, the DB connection parameters are read from an environment variable, MONGOHQ_URL. When I run the project in Netbeans on my laptop, how do I set this variable?

I tried adding it as a VM option with -DMONGOHQ_URL=... in Run -> Set Project Configuration -> Customize -> Run and as well in Actions -> Run project and Run file via main(), but to no avail. When the program reads it with System.getvar it’s not set.

Answer 1

Ok, I figured it out. This may be obvious to Java coders, but I’m not one, so here is what I cobbled together.

    String mongo_url = System.getenv("MONGOHQ_URL");
    // If env var not set, try reading from Java "system properties"
    if (mongo_url == null) {
        mongo_url = System.getProperty("MONGOHQ_URL");
    }

    MongoURI mongoURI = new MongoURI(mongo_url);
    this.db = mongoURI.connectDB();

    // Only authenticate if username or password provided
    if (!"".equals(mongoURI.getUsername()) || mongoURI.getPassword().length > 0) {
        Boolean success = this.db.authenticate(mongoURI.getUsername(), mongoURI.getPassword());  

        if (!success) {
            System.out.println("MongoDB Authentication failed");
            return;
        }
    }
    this.my_collection = db.getCollection("my_collection");