copy tree with gradle and change structure?

Question

Can gradle alter the structure of the tree while copying?

original

• mod/a/src
• mod/b/src

desired

Answer 1

Please see sample below. Gradle 4.3 does not have rename/move methods, so we can do renaming on the fly.

What was happened:

1. Load file tree into the memory. I used zip file from dependencies in my example
2. Filter items, which are in the target folder
3. All result items will have the same prefix: if we filter files from directory "A/B/C/", then all files will be like "A/B/C/file.txt" or "A/B/C/D/file.txt". E.g. all of them will start with the same words
4. In the last statement eachFile we will change final name by cutting the directory prefix (e.g. we will cut "A/B/C").
5. Important: use type of task "Copy", which has optimizations for incremental compilation. Gradle will not do file copy if all of items below are true:
   • Input is the same (for my case - all dependencies of scope "nativeDependenciesScope") with previous build
   • Your function returned the same items with the previous build
   • Destination folder has the same file hashes, with the previous build

task copyNativeDependencies(type: Copy) {
    includeEmptyDirs = false
    def subfolderToUse = "win32Subfolder"

    def nativePack = configurations.nativeDependenciesScope.singleFile // result - single dependency file

    def nativeFiles = zipTree(nativePack).matching { include subfolderToUse + "/*" } // result - filtered file tree

    from nativeFiles
    into 'build/native_libs'
    eachFile {
        print(it.path)

        // we filtered this folder above, e.g. all files will start from the same folder name
        it.path = it.path.replaceFirst("$subfolderToUse/", "")
    }
}

// and don't forget to link this task for something mandatory
test.dependsOn(copyNativeDependencies)
run.dependsOn(copyNativeDependencies)