Question

On a multi-project gradle build, can someone tell me what exactly is the difference between the “allprojects” section and the “subprojects” one? Just the parent directory? Does anyone use both? If so, do you have general rules that determines what typically is put in each one?

Related question: what is the difference between the two syntaxes (really for allprojects AND subprojects):

subprojects {  ...
}

and

configure(subprojects) { ...
}

When would you one over the other?

Answer 1

In a multi-project gradle build, you have a rootProject and the subprojects. The combination of both is allprojects. The rootProject is where the build is starting from. A common pattern is a rootProject has no code and the subprojects are java projects. In which case, you apply the java plugin to only the subprojects:

subprojects {
    apply plugin: 'java'
} 

This would be equivalent to a maven aggregate pom project that just builds the sub-modules.

Concerning the two syntaxes, they do the exact same thing. The first one just looks better.