Android Studio can't find library classes after Gradle build

Question

I'm trying to add a .jar library to my project into the /libs folder. Here is my grade.build:

    buildscript {
        repositories {
            mavenCentral()
        }
        dependencies {
            classpath 'com.android.tools.build:gradle:0.4'
        }
    }
    apply plugin: 'android'

    dependencies {
        compile files('libs/android-support-v4.jar', 'libs/java-api-wrapper-1.2.0-all.jar')
    }

    android {
        compileSdkVersion 17
        buildToolsVersion "17.0.0"

        defaultConfig {
            minSdkVersion 15
            targetSdkVersion 16
        }
    }

After I add that, I build my project and there are no errors. But when I try to use the class in my code private ApiWrapper wrapper, I get an error:

Gradle: error: cannot find symbol class ApiWrapper

I can't quite find where the error is. Is my grade.build not ok, or am I supposed to build it some other way?

Answer 1

Using the command line, in the root of your project, run :
./gradlew clean && ./gradlew build

Then recompile your project in studio and you should see your new lib.

Answer 2

Set minifyEnabled to false for all your library projects in build.gradle. See accepted answer by Scott Barta in this thread.

See accepted answer by Scott Barta in this thread