Introduction
I really like Gradle build system for JVM apps. It has flexibility like Ant and great dependency management capabilities like Maven. It addition, it doesn’t use XML notation, but Groovy programming language, so builds configurations are simple, concise, easier to read and easier to create. In my opinion, Gradle is truly modern build system for JVM apps. Nevertheless, there are projects, which are pretty old and use older systems like Ant. For example, all Hybris projects are based on Ant. Moreover, they have their custom setup and configurations, internal extensions system, etc. I was wondering if it’s possible to migrate Hybris Platform build from Ant to Gradle. That’s why I created a simple Proof of Concept.
Migrating from Ant to Gradle
If we want to use Gradle, we need to install it first.
sudo apt-get install gradle # if we're on Ubuntu Linux
brew install gradle # if we're on macOS
For more details and instructions for other systems, check official Gradle installation guide. Then, we need to go to our Hybris platform directory and navigate to hybris/bin/platform
After that, we need to initialize gradle inside this directory by running gradle
command. Next, we need to create gradle wrapper by running gradle wrapper
command. Now we should have the following elements in our directory:
.gradle
(directory)graldew
(wrapper file for Unix)gradlew.bat
(wrapper file for Windows)
Afterwards, we can create build.gradle
configuration file. It should have the following contents:
ant.importBuild 'build.xml'
apply plugin: 'java'
repositories {
jcenter()
}
task run() {
doLast {
exec {
executable "./hybrisserver.sh"
}
}
}
task cleanGeneratedDirs(type: Delete) {
delete "../../data"
delete "../../log"
delete "../../roles"
delete "../../temp"
}
task cleanConfig(type: Delete) {
delete "../../config"
}
dependencies {
compile fileTree(dir: 'lib', include: \['*.jar'\])
}
Now, we can execute the following command:
./gradlew clean build
and platform will be built. In order to initialize the platform, we can call:
./gradlew initialize
If we want to start the Hybris server, we can simply call:
./gradlew run
To clear directories generated during build and initialization, we can run:
./gradlew cleanGeneratedDirs
I tried to make clean
task dependent on this one, but I got a few errors and didn’t spend too much time on investigating them. As you probably noticed, this solution is just a wrapper around Ant build defined in build.xml
file and it’s not pure Gradle build configuration. Nevertheless, these tips may be useful for the people who need to have custom build configurations and dependencies. There’s no doubt that creating and maintaining configurations via Gradle is much easier and more convenient than doing the same job via Ant.
Summary
As we can see, it’s possible to migrate Hybris build from Ant to Gradle, but please remember that Hybris has a custom setup and it may not be the best decision in each case. We should always consider pros and cons of such solution and adjust it to our needs. In legacy systems, we often have to stick to existing setups because making “revolution” may be a huge overhead and doesn’t have to pay off. Moreover, all Hybris extensions also have build configurations based on Ant. On the other hand, I can highly recommend Gradle for greenfield JVM projects.
References
There’s another nice, short article describing migrating Java projects from Ant to Gradle: Easily Convert from Ant to Gradle (objectpartners.com).