Java Spark App deployed to Heroku

App deployed at: https://spark-greet.herokuapp.com/

• http://sparkjava.com/
• http://sparkjava.com/documentation
• https://devcenter.heroku.com/articles/deploying-java-applications-with-the-heroku-maven-plugin

A Spark Java App using Handlebars.

Deployment steps

Do this once:

• git init
• git add .
• git commit -m "initial commit"
• heroku create - you will need a heroku account.

Then deploy & redeploy using:

• mvn clean heroku:deploy

Install PostgreSQL

You can install PostgreSQL on Ubuntu using these commands:

sudo apt-get update
sudo apt-get install postgresql postgresql-contrib

Database setup

Once you have all the above installed you need to setup the database.

Create:

• a database called greeter
• and username - coder (or matching the you using on Linux) with a password of coder123 (or a password you choose).

Enter the password you want the use for your PostgreSQL user when prompted after executing the createuser command.

sudo -u postgres createdb greeter;
sudo -u postgres createuser coder -P;

Now run psql as the postgres user:

sudo -u postgres psql;

Grant the coder user access to the greeter database by running this command:

grant all privileges on database greeter to coder;

Type in \q to exit psql as the postgres user.

Connect to your database using: psql -d greeeter

Execute these SQL commands to create the person using \i db.sql in psql.

Or copy and paste this into psql and press enter

create table person(
    id serial not null primary key,
    first_name text,
    counter int
);

To do this on your own project create sql file containing the table create scripts that's in your projects root folder. Run the scripts using \i <your script file here>

You see which tables are in the database by using this command:

\dt

You can see the columns of a database using this:

\d+ <table_name_here>

To see all the columns in the person table do this:

\d+ person

After doing the above your local app should be able run using the local instance of PostgreSQL.

Database setup

To add a PostgreSQL database instance to Heroku for this application follow the steps below

heroku addons:create heroku-postgresql:hobby-dev

See the DATABASE_URL environment variable that was added to the Heroku app by typing.

heroku config

Connect to the Heroku PostgreSQL database instance using:

heroku pg:psql

Now create the person table in the database by running the db.sql script in the remote psql session.

\i db.sql