take the referral code form

buildscript
     {
    repositories {
    mavenCentral()
            }

    dependencies {
    classpath 'com.android.tools.build:gradle:2.1.3'
    classpath 'com.jakewharton.sdkmanager:gradle-plugin:0.9.+'
    }
  }

apply plugin: 'com.android.application'

android {
 compileSdkVersion 19
 buildToolsVersion "19.1.0"

defaultConfig {
    minSdkVersion 14
    targetSdkVersion 19
    versionCode 1
    versionName "1.0"
}

packagingOptions {
    exclude 'META-INF/maven/commons-io/commons-io/pom.xml'
    exclude 'META-INF/maven/commons-io/commons-io/pom.properties'
}

compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_7
    targetCompatibility JavaVersion.VERSION_1_7
}

packagingOptions {
    exclude 'META-INF/DEPENDENCIES.txt'
    exclude 'META-INF/LICENSE.txt'
    exclude 'META-INF/NOTICE.txt'
    exclude 'META-INF/NOTICE'
    exclude 'META-INF/LICENSE'
    exclude 'META-INF/DEPENDENCIES'
    exclude 'META-INF/notice.txt'
    exclude 'META-INF/license.txt'
    exclude 'META-INF/dependencies.txt'
    exclude 'META-INF/LGPL2.1'
}



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

 dependencies {
   compile fileTree(dir: 'libs', include: ['*.jar'])
   compile project(':libraries:android-goodreads-api')
   compile 'com.squareup.picasso:picasso:2.+'
   compile 'com.squareup:otto:1.3.4'
   compile 'com.squareup.retrofit:retrofit:1.5.0'
   compile ('com.squareup.retrofit:converter-simplexml:1.5.0') {
    exclude module: 'stax'
    exclude module: 'stax-api'
    exclude module: 'xpp3'
  }
 compile 'org.json:json:20140107'
 compile 'org.apache.commons:commons-io:+'
 compile 'org.apache.commons:commons-lang3:+'
 compile 'com.google.guava:guava:16.+'
 compile 'com.google.code.gson:gson:+'
 compile 'oauth.signpost:signpost-core:+'
 compile 'oauth.signpost:signpost-commonshttp4:+'
 compile ('org.simpleframework:simple-xml:+') {
    exclude module: 'stax'
    exclude module: 'stax-api'
    exclude module: 'xpp3'
  }
 }

apply plugin: 'com.android.library'

android {
  compileSdkVersion 19
  buildToolsVersion '19.1.0'

 defaultConfig {
    minSdkVersion 14
    targetSdkVersion 19
    versionCode 1
    versionName "1.0"
 }

 compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_7
    targetCompatibility JavaVersion.VERSION_1_7
 }
 buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'),     'proguard-rules.txt'
     }
  }
 }

dependencies {
  compile fileTree(include: ['*.jar'], dir: 'libs')
  compile 'com.squareup.picasso:picasso:2.+'
  compile 'com.squareup:otto:1.3.4'
  compile 'com.squareup.retrofit:retrofit:1.5.0'
  compile ('com.squareup.retrofit:converter-simplexml:1.5.0') {
    exclude module: 'stax'
    exclude module: 'stax-api'
    exclude module: 'xpp3'
  }
  compile 'org.json:json:20140107'
  compile 'org.apache.commons:commons-io:+'
  compile 'org.apache.commons:commons-lang3:+'
  compile 'com.google.guava:guava:16.+'
  compile 'com.google.code.gson:gson:+'
  compile 'oauth.signpost:signpost-core:+'
  compile 'oauth.signpost:signpost-commonshttp4:+'
  compile ('org.simpleframework:simple-xml:+') {
    exclude module: 'stax'
    exclude module: 'stax-api'
    exclude module: 'xpp3'
   }
 }

<string name="oauth_developer_key">your developer key</string>
<string name="oauth_developer_secret">your developer secret</string>
<string name="oauth_callback_url">com.goodreads://oauth_callback</string>

private static final String AUTHORIZATION_WEBSITE_URL = "http://www.goodreads.com/oauth/authorize?mobile=1";
private static final String ACCESS_TOKEN_ENDPOINT_URL = "http://www.goodreads.com/oauth/access_token";
private static final String REQUEST_TOKEN_ENDPOINT_URL = "http://www.goodreads.com/oauth/request_token";