Gradle dependency management based on build variant for java project - gradle

Question

I am using gradle to build a java spring project. What I am trying to do is:
If build target is dev or not specified, use dependency
compile("org.hsqldb:hsqldb")
If build target is prod or qa, use dependency
compile("mysql:mysql-connector-java:5.1.31")
I am not sure how to do this in gradle. First thing is how to pass the build type variable to the build script. The second thing is how to write the conditional dependency code based on the variable? Thanks in advance.

Answer 1

build.gradle is a Groovy file, so you can use if statements to dynamically change your dependencies, like this:
dependencies {
// other dependencies
if (someFlag) {
compile("org.hsqldb:hsqldb")
} else {
compile("mysql:mysql-connector-java:5.1.31")
}
}
To configure something like this one may use project properties:
dependencies {
// other dependencies
if (!project.hasProperty("targetEnv") || targetEnv == "dev") {
compile("org.hsqldb:hsqldb")
} else if (targetEnv == "prod" || targetEnv == "qa") {
compile("mysql:mysql-connector-java:5.1.31")
} else {
throw new InvalidUserDataException("Unknown target environment '$targetEnv'")
}
}
And now mysql dependency will be used when gradle is run with -PtargetEnv=qa or -PtargetEnv=prod, hsqldb — for cases when targetEnv is not specified or set to dev, and finally exception will be thrown if some unknown environment name is passed.