How to give System property to my test via Gradle and -D

Question

I have a a Java program which reads a System property

System.getProperty("cassandra.ip");

and I have a Gradle build file that I start with

gradle test -Pcassandra.ip=192.168.33.13

or

gradle test -Dcassandra.ip=192.168.33.13

however System.getProperty will always return null.

The only way I found was to add that in my Gradle build file via

test {
    systemProperty "cassandra.ip", "192.168.33.13"
}

How Do I do it via -D

Answer 1

The -P flag is for gradle properties, and the -D flag is for JVM properties. Because the test may be forked in a new JVM, the -D argument passed to gradle will not be propagated to the test - it sounds like that is the behavior you are seeing.

You can use the systemProperty in your test block as you have done but base it on the incoming gradle property by passing it with it -P:

test {
    systemProperty "cassandra.ip", project.getProperty("cassandra.ip")
}

or alternatively, if you are passing it in via -D

test {
    systemProperty "cassandra.ip", System.getProperty("cassandra.ip")
}