How Gradle Makes Windows and *nix App Deploy Scripts

Thanx to Mk Yong for this idea: http://www.mkyong.com/gradle/gradle-create-a-jar-file-with-dependencies/

Assets for this post are held here: https://github.com/jnorthr/gradleMakeWindowsBat.git


 

Here is a skeleton gradle project template to build an executable java jar plus all distributable assets for a ‘HelloWorld’ java source. This is to deploy your app as a stand-alone app on a client system, something like a GUI, or batch job app – NOT a web service.

The tasks to do this are a freebie when a build.gradle file includes a plugin module named ‘application‘ courtesy of

> apply plugin:’application’

Gradle Build Tool

This project includes a full gradle build tool as a ‘wrapper’ bit inside this download. So there’s no need install gradle on your system. You can run this app once you’ve done a git clone.

Git Source Code Control

Yes, you need Git installed on your system to get started. So change into a new folder/directory on your local system and do this:

git clone https://github.com/jnorthr/gradleMakeWindowsBat.git

This makes a project directory folder named gradleMakeWindowsBat so cd into that.

You could use this approach as a foundation to create several brand-new projects. Sure you would need to change gradleMakeWindowsBat to something else and the main class names would change too, but a lot of the setup work is done for you here.

Build / Check

Now you can just run the gradle wrapper like so:

> gradlew check

or

> bash ./gradlew check

This will ask gradle to download any dependency bits it needs to make it happy, and check that everything is cool on your installed version.

Build

Ok, to make it all happen, run gradlew again without options.

> gradlew

or

> bash ./gradlew

The default tasks are run. These are:

defaultTasks ‘clean’, ‘build’, ‘javadoc’, ‘installApp’, ‘startScripts’, ‘fatJar’, ‘distTar’, ‘distZip’, ‘run’

Tasks to Deploy An App

clean – gradle cleans the environment before starting

– build – when javac – compiles the HelloWorld module

javadoc – the javadoc API document is created with any source code comments

– installApp makes a folder named install and a sub-folder of gradleMakeWindowsBat containing /bin, /docs, /lib folders with all the pieces to do a full install on a client system. Ship the gradleMakeWindowsBat folder and change the client’s OS path variable to include gradleMakeWindowsBat/bin then on the command line you/they can run this job by typing the name of this  batch script file as gradleMakeWindowsBat  – easy-peasy !

startScripts – makes a folder of identical windoze and unix batch script files. These scripts will run the core job noted in the build.gradle file as

mainClassName = "com.jnorthr.DateUtils"

– yeah, you can change that for your own needs. Be sure to add the .jar files in build/libs to the system CLASSPATH variable.

fatJar – my favorite ! makes an executable jar file of the java/groovy/scala/jvm language classes and bits. You can just double click on the gradleMakeWindowsBat-all-1.0.jar file to run your app.

Alternatively from a command line with the jar in the same folder, you can do this:

> java -jar gradleMakeWindowsBat-all-1.0.jar

Everything needed has been included in this ‘fat’ jar !


Tasks to Transfer The Project Build Environment

When we need to move/copy/transfer a complete project that includes all the development tools, build stuff and source code controls, we can use either of these two tasks depending on the target computer system’s OS:

distTar packages up the full folder directory and makes it ready for shipment to a target computer system running Unix/Linux/Ubuntu etc.

– distZip packages up the full project folder directory in a compressed archive format. This is useful as a general-purpose tool to move a complete project around to target computer systems where the OS is unconventional like, say, Windows, IBM, DEC.

Both tasks run as a default set of tasks. Project build times may seem excessive as so many solutions are being produced. To speed things up you could alter the build.gradle file to remove these two tasks if you do not plan to move the project to another system.

Task to Run This App

– the run task starts execution of an app. The app name is declared in the build.gradle file as

> mainClassName = "com.jnorthr.DateUtils"

change to suit your own requirements.

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