gradle的配置编译和运行时

Question

I set up a classpath for my jar reference inside a jar.('classpath: 'wee.jar'), but apparently, I also need to type the following in my jar task

from {
    configurations.compile.collect {
        it.isDirectory() ? it : zipTree(it)
    }
    configurations.runtime.collect {
        it.isDirectory() ? it : zipTree(it)
    }

Can Someone explain to me what does from, configuration.compile.collect, runtime, and isDirectory and zipTree do? I look up google, but couldn't find any answer. I'm really new to gradle

Answer 1

For starters, you do not need both configurations.compile and configurations.runtime . In gradle, the compile time dependencies are already included in runtime config automatically - which makes compile a subset of runtime. Depending on what you're trying to achieve, you'll only need one or the other. So let's take this snippet:

configurations.compile.collect {
    it.isDirectory() ? it : zipTree(it)
}

A configuration represents a collection of artifacts and their dependencies. compile and runtime are among configs that are added by the java plugin. collect is groovy for: do the following operation for every element of a collection and return the result as a set. So effectively the line of code translates to - for all dependencies declared in configurations.compile , do the following and return the results as a set.

it is groovy shorthand for iterator - so it represents each element of the aforesaid collection.

if `it` is a directory
    include it as is, 
else
    unpack the file and then include it

( See zipTree reference here )

Putting the whole thing together, the code is taking all compile time dependency directories and all unpacked compile time jars and including that into the jar you're building.