#java spark

[nofatclips]

Java and Mongo and Spark and Freemarker 101

And to finally put the M in MVC, let's do the same but now reading the "world" part of our HTML page from a document stored in a MongoDB collection.

https://gist.github.com/nofatclips/5597919

Since the DBObject implements the Map interface, it can be passed directly to Freemarker.

[nofatclips]

Java and Spark and Freemarker 101

We managed to send a string of text to the browser using Spark and to create an HTML string from a template using Freemarker, so the next step is to mix the two to get the VC in MVC working.

https://gist.github.com/nofatclips/5597613

The code is pretty bad, just a mish mash of the previous two, no effort was made to make it something better than that.

[nofatclips]

Java and Spark 101

Once dealt with the gritty details, using Spark is very simple. By calling the get() method, you instruct the framework on where to handle the routing for you. And by implementing the handle() callback, you instruct it on how to do it.

https://gist.github.com/nofatclips/5594291

Once the program is running, the Hello World page should be available at the address:

http://localhost:4567/

Check out the output in the console, anyway.

[nofatclips]

Spark: A miminal JDK web framework

Ever felt that Java web framework requiring the Enterprise Edition, servlets, application servers and data management systems are just a little overkill? Enter Spark.

Spark is very minimal: it doesn't even support the whole MVC stack: you'll have to import other libraries for the model (Java Mongo) and the views. The HTTP/servlet part is delegated to Jetty.

Once dealt with importing the library into the project (using Maven?), you might also have to change the build settings to use the JDK 7 to compile (in Eclipse: Project -> Properties/Java Compiler) and the JRE 7 to run the compiled bytecode (in Eclipse: Project -> Properties/Build Path/Libraries)

Then, we're ready for the Hello World code.

[nofatclips]

Adding a Maven repository in Eclipse

When the artifact you want to import is not listed in the central Maven repo, you need to specify the repository to install it from. It's usually simpler to open the pom.xml file for direct edit (the tabs are in the lower part of the window and copy the info in.

In this case, following the M101J course for Mongo DB in Java, I'm adding the Spark web framework.

You might have to add the <repositories> tag yourself. All the XML snippets are on the Spark download page.