How to exclude certain files from Android Studio gradle builds?

Question

I am using Android Studio with Google Drive, which makes hidden system files visible (such as Icon and desktop.ini), causing errors, as described here. Rather than run scripts to delete these files, I'd like to instruct gradle 2.14 to ignore them.

In an attempt to figure out how to exclude files, I created files named "excludeme.txt" in the directories \app\src\main\res\values and in \app\src\main\java\com\hfad\stopwatch\. I unsuccessfully tried various modifications to the two build.gradle files in my project. None successfully excluded the file.

Specifically, I made the following modification to the build.gradle file for Module: app, per this question:

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'], excludes: ['**/excludeme.txt'])
                                                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'
    })
    testCompile 'junit:junit:4.12' 
}

I also added this to the android section of the same build.gradle file, per this question:

aaptOptions {
    ignoreAssetsPattern "!excludeme.txt"
}

I also added:

sourceSets {
    main {
        java {
            srcDir "src"                [I also tried w/o this line]
            exclude "**/excludeme.txt"
        }
    }
}

When I selected Build > Clean Project, which triggered a build, I got this output, which shows that the file in the resources folder was not ignored:

Information:Gradle tasks [clean, :app:generateDebugSources, :app:mockableAndroidJar, :app:prepareDebugUnitTestDependencies, :app:generateDebugAndroidTestSources]
C:\Users\Ellen\GoogleDrive\Ellen-CS115\AndroidStudioProjects\Stopwatch\app\src\main\res\values\excludeme.txt
Error:(1, 1) Error: Premature end of file.
Error:Execution failed for task ':app:mergeDebugResources'.
> C:\Users\Ellen\GoogleDrive\Ellen-CS115\AndroidStudioProjects\Stopwatch\app\src\main\res\values\excludeme.txt:1:1: Error: Premature end of file.

The results were the same if I removed the exclamation point:

aaptOptions {
    ignoreAssetsPattern "!excludeme.txt"
}

How do I properly instruct gradle to ignore files containing a certain pattern when building Android projects?

Update 1

Per Stefan's suggestion below, I added the following to the build.gradle file for Module: app:

android {
    [omitted]
    sourceSets.main.res.exclude '**/whatever.txt'
}

I added a file named whatever.txt in the res/layout directory, and the build failed with:

Error:Execution failed for task ':app:mergeDebugResources'.
> C:\Users\Ellen\GoogleDrive\Ellen-CS115\AndroidStudioProjects\Starbuzz\app\src\main\res\layout\whatever.txt: Error: The file name must end with .xml

Update 2

Per Nathan's suggestion, I added:

packagingOptions {
    exclude '**/whatever.txt'
    exclude 'src/main/res/layout/whatever.txt'
}

to build.gradle (Module: app) in the android section. No improvement:

Information:Gradle tasks [:app:generateDebugSources, :app:mockableAndroidJar, :app:prepareDebugUnitTestDependencies, :app:generateDebugAndroidTestSources]
/Users/spertus/GoogleDrive/Ellen-CS115/AndroidStudioProjects/MacTest/app/src/main/res/layout/whatever.txt
Error:Error: The file name must end with .xml
Error:Execution failed for task ':app:mergeDebugResources'.
> /Users/spertus/GoogleDrive/Ellen-CS115/AndroidStudioProjects/MacTest/app/src/main/res/layout/whatever.txt: Error: The file name must end with .xml
Information:BUILD FAILED

(This last build was on a Mac, unlike the others, which were on Windows.)

Answer 1

Looks like a recent change in gradle changed the DSL for sourceSets, so you now need to specify the exclude on the filter field:

android {
    sourceSets.main.res.filter.exclude '**/whatever.txt'
}

Answer 2

The Android plugin has its own concept of SourceSets: http://tools.android.com/tech-docs/new-build-system/user-guide#TOC-Configuring-the-Structure

So you'll probably want to do something like

android {
    sourceSets.main.res.exclude '**/whatever.txt'
}

Answer 3

In the child project, in your case I believe it is :APP, add the following to the build.gradle file.

packagingOptions {
    //Exclude the file(s) in this method. Provide the path and file name.    
    exclude 'src\main\res\layout\whatever.txt' 
}

The PackagingOptions DSL object allows you to control what files are included in the APK. exclude takes a string or pattern as an argument which will allow you to ignore files or directories by name or pattern.

EDIT Customizing which resources to keep from the Android Studio docs.

1. Create XML file in your project with a <resources> tag.
2. Add tools:keep="[list resources]"
3. Add `tools:discard="[list resources]"
4. Save the file in project resources at res/raw/keep.xml The build will not include this file.

The end file should look similar to the one in the Android Studio Docs

<?xml version="1.0" encoding="utf-8"?>
<resources xmlns:tools="http://schemas.android.com/tools"
    tools:keep="@layout/l_used*_c,@layout/l_used_a,@layout/l_used_b*"
    tools:discard="@layout/unused2" />

Answer 4

After much banging of head against keyboard, this worked for me:

apply plugin: 'com.android.library'

def getCurrentFlavor() {
    Gradle gradle = getGradle()
    String tskReqStr = gradle.getStartParameter().getTaskRequests().toString()

    Pattern pattern;

    if (tskReqStr.contains("assemble"))
        pattern = Pattern.compile("assemble(\\w+)(Release|Debug)")
    else
        pattern = Pattern.compile("generate(\\w+)(Release|Debug)")

    Matcher matcher = pattern.matcher(tskReqStr)

    if (matcher.find())
        return matcher.group(1).toLowerCase()
    else {
        println "NO MATCH FOUND"
        return "";
    }
}

android {
.
.
.
    sourceSets {
            main {
                if (getCurrentFlavor() == 'stripped') {
                    java.exclude('**/excluded1.java',
                    .
                    .)
            }
            java {
              srcDir 'main'
            }
          }
        } 
     }         

N.B. Credit to: How to get current flavor in gradle for writing the getCurrentFlavor method,