An exercise for my Web Application course
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Failed to load latest commit information.

Sample application

This is a simple application that can be used to practice deploying to Heroku, and writing single-page web applications.

Import the project in Eclipse

Install Maven.

Then run

mvn eclipse:clean eclipse:eclipse -DdownloadSources -DdownloadJavadocs

Then use Import... > Existing Project in Eclipse.

Run the project in Eclipse

In Eclipse, right-click on the it.xpug.example.main.Main class and select Debug As... > Java Application.

Then observe the application at http://localhost:8080/

Run the project from the command line

Install maven. Open a terminal window and cd to the directory of this project. Then run

mvn clean package
java -cp target/classes:"target/dependency/*" it.xpug.example.main.Main

Then observe the application at http://localhost:8080/

Exercise 0: deploy to heroku

There are many steps and things to learn. Don't despair if something doesn't work: ask for help to collegues, to google (expecially, to your teacher. Try experiments. Above all, try to understand what you are doing.

First thing: if you deployed this project as a zip file, scrap it and download again using git. First install git, then use

git clone

Check that the application works from the command line (see above.) Note that the app does not convert temperatures yet; for the moment, we are happy if we see the form in the browser.

Register yourself to Heroku. It's free. Then go to Heroku's dashboard on the web and create an application. Call it "aw-temperature-conversion-123456" where 123456 is your student ID number. You will be given your application's URL; you will need it.

Download the heroku tools. There are instructions on Heroku's web site for how to download the correct version for your system (Mac OS or Ubuntu). If you did it correctly, you should be able to run the


command and see some help messages. Then run

heroku login

This will ask you to create a digital key if you don't have one already.

Now you will connect your repository for this project, to heroku. Do this with the command

git add remote heroku

where XXX is your application's URL (see above). Then you deploy to heroku with

git push heroku master

This will take some time. When it's finished, it will print your application's URL (this is the url for interacting with the app; the other url we used before was the Heroku deployment url.) It will be something like

Open it. It will probably be an error. This is normal :) Try to understand what the error is by reading your application's logs with

heroku logs

The solution is here: there is an error in the Procfile. This is the file that tells Heroku how it should run our application. It is of the form

web: java XXX

where "java XXX" should be the command that we used before to run the application (we don't need to tell to Heroku to run maven; that is done automatically by Heroku). You will see that there is an error in the arguments to the java command in the Procfile. Fix it. Then commit your change to git with

git add -A
git commit

Then deploy again with

git push heroku master

This time it should take less time. This time the application should work.

Exercise 1: make it work

We have the UI in the index.html file, but it does not work. Your task is to add behaviour in JavaScript so that the index page calls the server with Ajax to perform the temperature unit conversion work.