Over a million developers have joined DZone.
{{announcement.body}}
{{announcement.title}}

Maven and Java Multi-Version Modules

DZone's Guide to

Maven and Java Multi-Version Modules

· DevOps Zone ·
Free Resource

Do you need to strengthen the security of the mobile apps you build? Discover more than 50 secure mobile development coding practices to make your apps more secure.

Introduction

Usually, a project has a minimum Java version requirement and that applies to all of its modules. But every rule has its exceptions, as recently I stumbled on the following issue.

One open source project of mine mandates Java 1.6 for most of its modules, except one requiring the 1.7 version.

This happens when integrating external libraries having different Java requirements than your own project.

Because that one module integrates the DBCP2 framework (supporting at least Java 1.7), I need to instruct Maven to use two different Java compilers.

Environment variables

We need to define the following environment variables

ENVIRONMENT VARIABLE NAME ENVIRONMENT VARIABLE VALUE
JAVA_HOME_6 C:\Program Files\Java\jdk1.6.0_38
JAVA_HOME_7 C:\Program Files\Java\jdk1.7.0_25
JAVA_HOME %JAVA_HOME_6%

If you enjoy reading this article, you might want to subscribe to my newsletter and get a discount for my book as well.

Vlad Mihalcea's Newsletter

The parent pom.xml

The parent pom.xml defines the global java version settings

<properties> <jdk.version>6</jdk.version> <jdk>${env.JAVA_HOME_6}</jdk> </properties> 

We need to instruct both the compiler and the test plugins to use the configured java version.

<build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <configuration> <source>${jdk.version}</source> <target>${jdk.version}</target> <showDeprecation>true</showDeprecation> <showWarnings>true</showWarnings> <executable>${jdk}/bin/javac</executable> <fork>true</fork> </configuration> </plugin> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-surefire-plugin</artifactId> <configuration> <jvm>${jdk}/bin/java</jvm> <forkMode>once</forkMode> </configuration> </plugin> </plugins> </build> 

If you enjoyed this article, I bet you are going to love my book as well.






The specific module pom.xml

Those modules requiring a different java version, just need to override the default settings:

<properties> <jdk.version>7</jdk.version> <jdk>${env.JAVA_HOME_7}</jdk> </properties> 

And that’s it, we can now build each modules using its own specific minimum java version requirement.

Check out tips for blazing the way from agile to DevSecOps with security built into your mobile app toolchain.

Topics:
java ,devops ,maven ,tips and tricks

Published at DZone with permission of

Opinions expressed by DZone contributors are their own.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}