After we succesfully installed Helma, we will write our first application: The traditional "Hello World" example.

In your Helma directory you will find a folder named "apps". There you will find the existing apps, that had been distributed with Helma, and you can access through the "Base"-application. ( http://localhost:8080 ).

To create a new application you have to open the apps.properties file in the Helma directory with a texteditor:

# list of applications to be started by helma
base
base.mountpoint = /
bloggerapi
himp
hopblog
lillebror
manage
helloworld


As you can see the apps.properties hold a list of applcation names, that are running at your server. So we add a line at the end of the file with the name of our "helloworld" application.

When you go back to the helma/apps folder you will find a newly created helma/apps/helloworld folder.

In there you will find 4 subfolders:

helma/apps/helloworld/global
helma/apps/helloworld/hopobject
helma/apps/helloworld/root
helma/apps/helloworld/user

For our "Hello World" application we will just need the root folder. As the name says this is the "root"-directory of our application, which we can access via the URL http://localhost:8080/applicationname (in our case http://localhost:8080/helloworld).

Create a textfile called "main.hac" in the root folder, and open it with a text editor. Type the following line:
res.write("Hello World!");
and save the file.

".hac" files are our "Helma Action" files, which we can access via the URL. "main.hac" is something like index.html on a static web server. That means this file will be automatically called when we access a Helma node (in this case the root-node).

So helma/apps/helloworld/root/main.hac can be called via the URL's http://localhost:8080/applicationname/main or just http://localhost:8080/applicationname .

What you can see in your browser should be the line:

Hello World!