Getting Started with the Alfresco Maven SDK
Jeff Potts, Metaversant Group
- Important Concepts
- Your First Project
- Creating a Project for Share Tier Customizations
- Other Topics to Explore on Your Own
- Where to Find More Information
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This tutorial is for people who have been handed a project that requires you to customize Alfresco in some way and you're thinking, "Now what?". By the end, you'll know:
- How to create a new Alfresco project using the Alfresco Maven SDK
- What goes where depending on the type of customization you are doing
- How to create and run tests
- How to produce an artifact suitable for deploying to your environment or sharing with the community.
This tutorial should be considered a pre-requisite before moving on to more detailed tutorials on things like content modeling, custom actions, behaviors, advanced workflows, or web scripts.
Before we jump in, a quick disclaimer: There are almost always multiple routes to a given solution. In this tutorial, I'm going to take you through the most direct, safest route that will get you up-and-going quickly. Later, if you decide you want to change things up or explore other paths, that's great.
You don't need to know much about Maven, Alfresco, or why this SDK exists before jumping in but it kind of helps set the scene, so let me take you through those three concepts quickly.
Apache Maven is essentially a build management tool. It has many features, but the primary time-saving feature is its ability to understand the dependencies your project relies on (and the dependencies of those dependencies and so on). Maven can then retrieve and cache those dependencies for you. If you've ever spent time chasing down JAR file after JAR file, the value of such a tool will be immediately obvious.
Alfresco Module Package (AMP)
An AMP is a ZIP file with a folder structure that follows a specific convention. AMP files are used to make it easy to share and deploy customizations to the Alfresco platform. If your project is about making customizations to the repository tier (the /alfresco web application) you will create a "repo" AMP. If your project is about making customizations to the Share tier (the /share web application) you will create a "share" AMP. It is quite common for a project to require changes in both tiers, so in that case you will create two AMPs.
Alfresco Maven SDK
The goal of the Maven-based SDK is to make it extremely easy for you to get started with Alfresco development. It consists of a project template (an "archetype" in Maven parlance) and some built-in smarts that make Maven understand how to create AMPs and deploy them to Alfresco.
If you are writing your own custom application that is separate from the Alfresco and Share WARs you don't need the Alfresco Maven SDK. But if you intend to write code that runs within either of those web applications, the Alfresco Maven SDK is where you need to start.
A quick word about versions. This tutorial assumes you are using Alfresco Maven SDK 2.2.0. The version you use may depend on which version of Alfresco you want to use. Check the Alfresco SDK Compatability Matrix to be sure. If you are using a version older than 4.x you'll have to use the old Ant-based SDK. The rest of this document won't apply to you.
Now you have a high-level understanding of Apache Maven, AMPs, and the Alfresco Maven SDK. It's time to see them in action.
Your First Project
Let me show you how easy it can be to get started with Alfresco development using the Alfresco Maven SDK. Before I start I'm going to assume you have JDK 1.8 installed as well as Apache Maven 3. You don't need to download anything else. Seriously. Not even Alfresco.
Create an empty directory. It doesn't matter where it is or what you call it. I'll refer to it as $TUTORIAL_HOME. We're going to be creating some additional directories in here shortly.
Now let's create a new project. For now, let's assume you want to create something that you will deploy to the Alfresco repository tier such as a custom content model, some custom rule actions, a new set of web scripts, or some Activiti business processes. It doesn't really matter. To create the new project, change directories to $TUTORIAL_HOME, then run this command:
mvn archetype:generate -Dfilter=org.alfresco:
- Maven will do some work and eventually ask you to choose an "archetype". You're basically selecting from a library of template projects. There are three available:
Our goal is to create an AMP that can be deployed to Alfresco so the second one is the one we want. Type 2 and hit enter.
Now Maven is asking you to specify the version of the archetype you want to base your project on. Currently, the latest version is 2.2.0 which is the 8th option in the list, so type 8 and hit enter. Again, the version you choose may not support all Alfresco versions, so check the compatibility matrix I mentioned earlier.
Maven now asks for a groupId. You should be thinking "Java package". My examples always assume I am working at a fictitious company called SomeCo, so I will specify "com.someco" here. Specify what makes sense in your case and hit enter.
Next is the artifactId. You can think of this as what you want your project to be called. It will also be the ID of your AMP so make it something unique. You should also append the string "-repo" to your artifactId because this module is intended to be deployed to the repository tier. I'm going to specify "someco-mvn-tutorial-repo" for mine followed by enter.
Take the default package, which will match your groupId.
At this point Maven will show you the values you entered plus some others that were defaulted and ask you to confirm your choices. If you want to change something you can specify "N" and then make changes or you can enter "Y" to continue. You can always change these values later if needed, so specify "Y" followed by enter.
Now Maven is going to do some work. When it is done you will have:
- A project structure organized exactly how it needs to be to support your Alfresco development
- Default configuration files
- Minimal Java code and an accompanying unit test just to verify that everything works
- Configuration required to run a local instance of Alfresco suitable for testing
- A default POM (Project Object Model) XML file that tells Maven what your project depends on
The SDK defaults to a fairly recent Alfresco version. If you need to run on a different version, you might want to edit someco-mvn-tutorial-repo/pom.xml and change it before you proceed.
Let's Run It
You haven't downloaded anything. You haven't edited anything. All you've done is tell Maven to create a project based on a template. But the cool thing is this: Your project is runnable right now.
cd someco-mvn-tutorial-repo mvn integration-test -Pamp-to-war
If you watch the output, you'll see that Maven is downloading everything it needs to compile the project, creating an AMP, deploying the AMP to the Alfresco WAR, deploying the Alfresco WAR to the embedded Tomcat server, and starting the server up. Eventually you'll see:
2014-01-15 18:01:19,339 INFO [repo.module.ModuleServiceImpl] [localhost-startStop-1] Found 1 module(s). 2014-01-15 18:01:19,480 INFO [repo.module.ModuleServiceImpl] [localhost-startStop-1] Installing module 'someco-mvn-tutorial-repo' version 1.0.1401151758.
Which means that the module your project generated was recognized by the Alfresco server.
Once you see:
Jan 16, 2014 8:38:20 AM org.apache.coyote.AbstractProtocol start INFO: Starting ProtocolHandler ["http-bio-8080"]
You should be able to go to:
And you will see the "Welcome to Alfresco' page. In versions prior to 5.0.d this would be the Alfresco Explorer login page. Log in using "admin" and "admin". If you want to verify that you can log in, go to the Alfresco web script console, which is:
When you are done poking around, go back to the window where you ran your Maven command and type ctrl-c to shutdown the server.
If you get an out-of-memory error when you run the integration test, you may need to pass some JVM memory parameters to Maven. One way to do that is by setting the MAVEN_OPTS environment variable. For example, I have mine set to:
With MAVEN_OPTS set you should not see any out-of-memory errors.
What Just Happened?
You asked maven to run the "integration-test" goal using the "amp-to-war" profile. This causes the project to be built, deployed as an AMP to a fresh Alfresco WAR, and run on the embedded Tomcat server. Once it started up, you were able to log in to the admin console and the web scripts console.
If you go look in the target directory you'll see the AMP that was produced and subsequently deployed to the Alfresco WAR. In my case it is called "someco-mvn-tutorial-repo.amp". This file is what you would give to your IT team if you were ready to deploy your repository tier changes to a real Alfresco server.
Other Commands for Invoking the Build
You may not always need to start up the Alfresco server and leave it running. If you just want to build the project, run the unit tests, and package the AMP, you can run:
If you want to install the AMP into your local Maven repository you can run:
You may have noticed that the default project includes a simple unit test. By default, Maven will automatically run the unit tests in your project. You can see this happening in the output:
------------------------------------------------------- T E S T S ------------------------------------------------------- Running org.alfresco.demoamp.test.DemoComponentTest
It's a good practice to make sure that your project always includes unit tests and to run them every time you build. Many organizations run CI (Continuous Integration) tools that depend on this being the case. If you don't want to run tests for some reason you can skip them, like this:
mvn install -DskipTests=true
If you want to delete all of the compiled artifacts that Maven created and start fresh you can run:
If you also want to delete the embedded database, Alfresco content store, indexes, and log files that were created by running the test Alfresco server, you can run:
mvn clean -Ppurge
Now you know how to create a new Alfresco project from an archetype and the fundamentals of running builds with and without unit tests. Next up, you'll learn about working with your new project in an IDE and you'll get a tour of the default project structure.
In the log4j.properties file that exists in the module directory, the log4j.properties file includes
You'll probably want to replace that with settings that match your package structure.
To set the module.log.level you can either do it when you run Maven, like this:
mvn install -Dmodule.log.level=DEBUG
Or you can edit the pom.xml and add it to the properties, like this:
If you change the pom.xml, then the AMP that gets produced will include that setting, and subsequently, the WAR the AMP gets deployed to will write log statements accordingly. This may or may not be what you want. If you aren't sure, it's probably best to set it using the command-line so it doesn't accidentally get set in your AMP.
Working With Your Project in an IDE
Althought it isn't required, most people prefer to work in an IDE when developing Alfresco customizations. Any IDE will do, but the most popular one is Eclipse so let's see how that works.
I'll be using the Luna version of Eclipse Java EE IDE for Web Developers. It comes with built-in Maven support.
To open the project we created earlier in Eclipse, do this:
Select File, Import, Maven, Existing Maven Projects. Click Next.
Specify the directory that contains the someco-mvn-tutorial-repo folder. Eclipse will inspect that folder and show your project in the projects list. Make sure the checkbox next to the project name is checked, then click Next.
After clicking Finish, the project is imported into your Eclipse workspace.
Understanding the Project Structure
The folder structure of your project is a bit more pleasant to explore in your IDE. Let's see what we've got.
pom.xml In the root of the project directory you'll see pom.xml. This tells Maven everything it needs to know about your project. Remember those settings you specified when you created the project from the archetype? You can make changes to those settings here. For example, version 2.2.0 of the archetype assumes you are working with Alfresco Community Edition 5.1.e. If you wanted to work with a different version, you would simply change those properties and then tell Maven to update and it will take care of the rest.
src/main/java This is where you should create your own packages to organize your Java code. Things like custom action executer classes, custom behaviors, Java-based controllers for web scripts go here. If you don't know what those are, don't worry, there are tutorials available here. These files will ultimately be placed in a JAR. When the AMP is installed into the Alfresco WAR, the JAR will be placed under WEB-INF/lib.
src/test Everything under src/test is about running unit tests. The unit tests themselves go in src/test/java. Any resources those classes need go in src/test/resources. In src/test/properties/local you'll see an alfresco-global.properties file. If you are already know something about Alfresco you know that this is used to configure Alfresco. In this case, it is only used when running the embedded Alfresco server for testing purposes.
src/main/amp Everything else goes somewhere in this part of the project. The structure of an AMP is well-documented so I don't want to duplicate that here. Let me just point out the highlights:
- The module.properties file tells Alfresco what it needs to know about this AMP such as its ID, version, the minimum and maximum version of Alfresco required to run the AMP, and any other AMPs on which this one depends.
- The config/alfresco/module/someco-mvn-tutorial-repo directory is the heart of the AMP. This is where you place Spring config XML files, content model XML files, and user interface configuration. As you'll see in later tutorials, I prefer separate sub-directories for each of these things.
- If your module includes web scripts or workflows, those don't reside under the module directory. Instead, those would go under config/alfresco/extension/templates/webscripts and config/alfresco/extension/workflows.
- Your module may include client-side resources that need to be deployed to the root of the web application. Those go in src/main/amp/web in directories such as css, jsp, scripts, and images.
You should check this entire project into source code control. You will want to configure your source code control client to ignore the target directory and the alf_data_dev directory.
Now that you understand how to create a project for repository tier customizations, let's take a look at the Share tier. As part of that I'll show you another option for creating projects without leaving Eclipse.
Creating a Project for Share Tier Customizations
The first thing you should realize is that the structure for a project that creates repo tier customizations is exactly the same as one that targets Share tier customizations. From an Alfresco Maven SDK perspective, there are two things different about a Share project: The project's dependencies and the WAR the AMP will be deployed to.
Try It: Create a Share Project Using the Archetype
Let's create a new project for Share customizations. You could go into the command line and run the exact same archetype command you ran earlier, selecting the "share-amp-archetype" and specifying a new artifactId. If you are not using Eclipse, go ahead and do that now, then skip the next section.
Another option is to configure Eclipse so you can create new Alfresco projects using the Alfresco Maven SDK without leaving the IDE. Let's do that.
- File, New Maven Project.
Specify $TUTORIAL_HOME, then click next.
Click Configure so we can add Alfresco's catalog to the list.
- Click Add Remote Catalog
Specify "http://repo.maven.apache.org/maven2/archetype-catalog.xml" as the Catalog File. Specify "Alfresco Archetypes" as the description. Then, click OK and OK again to close the Preferences panel.
- Now select "Alfresco Archetypes" in the catalog and you'll see a bunch of archetypes show up in the list.
- Specify "org.alfresco.maven.archetype" in the filter and you'll see the same three archetypes that were presented to you as options on the command line at the start of the tutorial.
Select the share-amp-archetype and click Next.
Specify "com.someco" for the groupId and "someco-mvn-tutorial-share" as the artifactId. Similar to the command line step, I changed my alfresco_target_version from "5.0.c" to "5.0.d". Then click Finish.
Now your Share customization project is in your workspace. The next time you create a new project using the archetype, it will be a few less steps because you won't have to add the catalog.
Understanding the Share Project Folder Structure
As I mentioned earlier, the structure of this project is exactly the same as the one we created for our repo project. The only difference worth mentioning is that in the repo project, things like web scripts went into src/main/amp/config/alfresco/extension/templates/webscripts. In a Share project, those go in src/main/amp/config/alfresco/web-extension/site-webscripts.
Running an Integration Test with Share
Often you will work on both repo tier customizations and share tier customizations at the same time. Your Share tier needs an Alfresco repository to talk to. One way to do that is to tell Maven to start your repo project using:
cd someco-mvn-tutorial-repo mvn integration-test -Pamp-to-war
And then start your Share project using:
cd someco-mvn-tutorial-share mvn integration-test -Pamp-to-war
The Share project configuration defaults its Tomcat to port 8081 so that it won't conflict with the repository project's Tomcat.
Once both servers come up, you can go to http://localhost:8081/share and log in to test your module.
Other Topics to Explore on Your Own
You now know how to use the Alfresco Maven SDK to create projects for both your Alfresco repository customizations and your Alfresco Share customizations. If you are new to Alfresco development, I hope you agree it is really easy to boostrap a project to get started.
There are many topics that weren't covered in this tutorial. I'll leave you to explore those on your own. Here are a few:
- This tutorial covered the AMP archetype. But the Alfresco Maven SDK includes another archetype called All-in-One. That archetype gives you a complete Alfresco installation including SOLR. This is often overkill for most customizations, but if you are doing development that really needs all of Alfresco's dependencies installed, including other AMP-based projects, you can use the All-in-One archetype to do that.
- The Alfresco Maven SDK supports both Community Edition and Enterprise Edition. If you need help accessing the Enterprise Edition artifacts, contact Alfresco Support.
Where to Find More Information
- The official documentation on the Alfresco Maven SDK is on http://docs.alfresco.com.
- The Instant Apache Maven Starter book by Maurizio Turatti and Maurizio Pillitu might be a good resource if you are interested in learning more about Apache Maven.
- Gethin James' Getting Started with Alfresco Development presentation from Alfresco Summit
- The Alfresco Developer Series on ECM Architect has free tutorials on custom content models, actions, behaviors, workflows, and web scripts.