java.lang.ClassNotFoundException on custom library

Question

I created a library and this library use another external library (just one).

This is the configuration of my library:

apply plugin: 'com.android.library'

android {
    compileSdkVersion 26

    defaultConfig {
        minSdkVersion 15
        targetSdkVersion 26
        versionCode 1
        versionName "1.0"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }

}

dependencies {
    implementation fileTree(include: ['*.jar'], dir: 'libs')
    compile ('com.github.Paroca72:sc-gauges:3.0.1') {
        transitive=true
    }
}

Export the library, as .aar, using gradle -> :library -> assembleRelease. Now iclude the library in a new project using "import .JAR/.AAR package" and including it in "module dependency"..

In the coding phase I no have errors but when I try to start the application I have this kind of exception:

Caused by: java.lang.ClassNotFoundException: Didn't find class "com.sccomponents.codes.gauges.ScArcGauge" on path: DexPathList[[zip file "/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/base.apk", zip file "/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/split_lib_dependencies_apk.apk", zip file "/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/split_lib_slice_0_apk.apk", zip file "/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/split_lib_slice_1_apk.apk", zip file "/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/split_lib_slice_2_apk.apk", zip file "/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/split_lib_slice_3_apk.apk", zip file "/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/split_lib_slice_4_apk.apk", zip file "/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/split_lib_slice_5_apk.apk", zip file "/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/split_lib_slice_6_apk.apk", zip file "/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/split_lib_slice_7_apk.apk", zip file "/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/split_lib_slice_8_apk.apk", zip file "/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/split_lib_slice_9_apk.apk"],nativeLibraryDirectories=[/data/app/com.test.test-oKxgn-etFOgh1n6SqKQU5Q==/lib/x86, /system/lib, /vendor/lib]]

Referred to the external library "com.sccomponents.codes.gauges.ScArcGauge" that was include in my own library..

What wrong?

I'm using Android Studio (latest version)

Answer 1

Most likely when you included your library via Android Studio you ended up with something like

compile 'yourlibrary":1.0.0@aar'

So it means that only the aar will be pulled in and not your dependencies. You need to change it to

compile ('yourlibrary":1.0.0@aar'){ transitive=true }

Answer 2

Please follow the below steps.

1. Right click on your project and select Properties.
2. Select Java Build Path from the menu on the left.
3. Select the Order and Export tab.
4. From the list make sure the libraries or external jars you added to your project are checked.
5. Finally, clean your project & run.

May be because its not added the library at run time.