GeoNetwork from Scratch II : Attack of the IDEs

We have already seen how to compile and run a basic GeoNetwork instance. Although we know that real developers will probably skip this step too, for new developers in GeoNetwork, it will be relief to have an IDE to work with. I know that many GeoNetwork developers use NetBeans or Intellij but as I am used to work with Eclipse, that’s what we are going to explore on this post.

First of all: Eclipse has better support for Maven projects on each version. So, to avoid headaches, just download the latest eclipse available.Eclipse has many installer tutorials, so I won’t stop here explaining how to run eclipse. I will just assume you know how to do it.

To run GeoNetwork from eclipse is very very easy. Just right click on the Package Explorer view to import -> As Maven Project over the folder you already had cloned on the last post:

Import As Maven Project - Eclipse as GeoNetwork IDE
Import As Maven Project
Import As Maven Project - Eclipse as GeoNetwork IDE
Import As Maven Project

There is still something Eclipse does not support right about GeoNetwork: we have a classes folder that Eclipse tends to misconfigure. So, go to that folder, right click and remove as source folder. To do this, go to the “web-app” project and right click on src/main/webapp/WEB-INF/classes. Select Build Path > Remove From BuildPath.

Then, completely remove the folder from the source code. Don’t worry, it’s git, you can recover it later. You can also do this by right-clicking on the folder and selecting Delete. Yes, you are sure you want to delete folder “classes“.

Now, update as maven project right clicking on the project “web-app” and selecting Maven > Update Project …

update project - Eclipse as GeoNetwork IDE

Once this finishes, you can restore the folder we previously removed. Go to the “web-app” project, right click on src/main/webapp/WEB-INF and select Replace With >HEAD Revision. Yes, you are sure.

Congratulations! You are ready to use Eclipse to modify GeoNetwork.

But wait, how do we run GeoNetwork inside Eclipse to be able to debug?

We have several approaches here. Remember the jetty command to run GeoNetwork from the console? It is available also inside Eclipse (right click on web-app and Run As > Maven Build) and you can add some maven variables to be able to run in parallel a debug watch to debug your code. You can also set up a Tomcat server inside Eclipse and run GeoNetwork from it. This second option is more easy for beginners, so that’s what we are going to do now.

First, you have to create a Tomcat server inside Eclipse. So, search for the “Servers” tab and right click on it. Select New > Server. You will see a windows offering different types of servers. We will select the Tomcat v.7.0 Server one. You will probably won’t have any server runtime environment configured for it, but you can “Add…” a new one. There are many tutorials[1][2] for this, so we won’t stop here.

On the following window, you can select which applications to run. Obviously, you choose the one called “web-app” and Finish.

Now, you will have a new Server on the Servers tab. select it (left-click) and click on the green arrow just on the top of that tab. You will see on the “Console” tab all the output of GeoNetwork starting up. Once it is started, you can enter GeoNetwork the same way as before, using http://localhost:8080/geonetwork

Have fun customizing GeoNetwork!

GeoNetwork From Scratch I : The Phantom Catalog

GeoNetwork, your friendly spatial catalog, never has been an easy software to deal with. But specially after the 3.0 version release, many things have changed. On this series of posts we will try to help new developers start with it.

GeoNetwork logo
The yoga man

The source code is available on a public repository on Github. This means that you can clone, fork and propose pushes of your custom changes. If you are not familiar with repositories of code or git, you should check this quick manual.

Maven and Java

It is built using mavenversion 3+. Therefore, it is written on Java and requires version 7 or more. Can be run both with OpenJDK or the Oracle version.You will need git and maven installed on your local machine to work. There are several ways to install this on your local machine; for example if you have a Debian based OS (like Ubuntu), you can install them with just this command:

sudo apt-get install maven git

Make sure you installed maven version 3!!

$ mvn –version
Apache Maven 3.2.1 (ea8b2b07643dbb1b84b6d16e1f08391b666bc1e9; 2014-02-14T18:37:52+01:00)
Maven home: ….

Remember that this will also install java on your system. You can check that the version is the right one with the following command:

java -version

So, the very first step once you have your environment set up is clone the repository on your local machine. That can be done on the command line using the following command inside an empty folder where the source code will be populated:

cd yourEmptyFolder
git clone https://github.com/geonetwork/core-geonetwork.git
git submodule init
git submodule update

As you can see, all the source code shown on github is also available on your local machine now.

Internal Structure of GeoNetwork

The source code is split on several smaller maven projects. To run it, you have to build all of them and run the project named “web“.

If you are familiar to maven, you will probably have guessed that you have to run a package install command on the root folder of the source code. But if you try that, maven will warn you that for building it you need more memory than the default memory provided to maven.

So, you will have to export the maven options to increase the memory like this:

export MAVEN_OPTS="-Xmx512M -XX:MaxPermSize=256M"

At this point we are not interested in running the tests, so you can skip them using the parameter “-DskipTests”:

mvn package install -DskipTests

At the end of this build (which can take long, depending on your network connection, as it has many third party libraries), you will see something like this:

------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 02:19 min (Wall Clock)
[INFO] Finished at: 2015-07-17T10:36:43+01:00
[INFO] Final Memory: 232M/441M
[INFO] ------------------------------------------------------------------------

This will generate a war file you can use in any Java Application Container (server) like Tomcat on web/target/geonetwork.war

Running GeoNetwork

Congratulations! You are ready to run it. To do this, just go to the web folder and run jetty in there:

cd web; mvn jetty:run

After jetty starts, you can see your running spatial catalog by opening a browser and enter to http://localhost:8080/geonetwork

Continue in Attack of the IDEs

What is GeoNetwork?

GeoNetwork is a server side application that allows you to maintain a geographic referenced metadata catalogue. This means: a search portal that allows to view metadata combined with maps.

GeoNetwork logo
The yoga man

Based on Free and Open Source Software, it strictly follows different standards for metadata, from Inspire to OGC. It implements the CSW interface to be able to interact with generic clients looking for data. It also has built-in harvesters to connect to other servers and populate data.

This has allowed GeoNetwork to expand to a lot of organizations. For example: the swiss geoportal or the brasilian one, not forgetting the New zealander. GeoNetwork is the most used open sourced spatial catalog in the world. You can find it in most of the public administrations that use free and open source software.

The catalogue deploys on a java application container (like tomcat or jetty). It works over the Jeeves framework. Jeeves is based on XSLT transformation server library. This allows a powerful development of interfaces, for humans (HTML) or machines (XML). Therefore, it makes metadata from GeoNetwork to be easily accessible by different platforms.

Recently half-refactored to Spring and AngularJS, GeoNetwork has a REST API and an event hook system to make extensions and customizations easier.