Android external library issue

Question

I am trying to use an existing Android project as a library for my app:

https://github.com/LarsWerkman/HoloColorPicker

The java code compiles, but when I run my app the following error occurs:

java.lang.ClassNotFoundException: Didn't find class
"com.larswerkman.colorpicker.ColorPicker" on path: 
DexPathList[[zip file "data/app/myApp.apk"], nativeLibraryDirectories=
[/data/app-lib/myApp, /system/lib]]

I know that I am not the first to address this exception, but I am really out of inspiration. I tried the following:

• Include the project in Properties -> Android -> Add...
• Include the project in Java Build Path -> Projects -> Add...
• Mark the project in Java Build Path -> Order and Export
• Include the .jar in Java Build Path -> libraries -> Add JARs

NONE of these fixes the problem. I want to know what the propper way is to include a project as a library.

Also, the documentation of the ColorPicker project, says that I include this somewhere as a dependency:

dependencies {
    compile 'com.larswerkman:HoloColorPicker:1.4'
}

In what file should I include this?

Answer 1

You should include this in build.gradle file of your application.

This is how build.gradle would like:

apply plugin: 'com.android.library'

android {
    compileSdkVersion 21
    buildToolsVersion "21.1.2"

    defaultConfig {
        minSdkVersion 14
        targetSdkVersion 21
        versionCode 1
        versionName "1.0"
    }
    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
        }
    }
}

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:21.0.3'
    compile 'com.android.support:recyclerview-v7:+'
    compile 'com.android.support:support-v4:+'
    compile 'com.larswerkman:HoloColorPicker:1.4'
}

Just see above I have included HoloColorPicker library.