studio - Android Build con Gradle y ProGuard: "El archivo de salida debe especificarse después de un archivo de entrada, o estará vacío"

proguard tutorial

Question

Estoy creando una construcción con diferentes sabores con Gradle. Solía ​​funcionar bastante bien hasta ahora, hasta que quise habilitar Proguard . He habilitado minifyEnabled para mi versión de compilación y ahora tengo una excepción que dice:

" Caused by: org.gradle.internal.UncheckedException: java.io.IOException: The output jar [.../app/build/intermediates/multi-dex/dev/release/componentClasses.jar] must be specified after an input jar, or it will be empty. " Caused by: org.gradle.internal.UncheckedException: java.io.IOException: The output jar [.../app/build/intermediates/multi-dex/dev/release/componentClasses.jar] must be specified after an input jar, or it will be empty.

¿Alguien sabe qué está causando esta excepción? Básicamente quiero habilitar ProGuard antes de lanzar mi aplicación. Aquí está mi archivo de Gradle a continuación.

lintOptions {
    abortOnError false
}

dexOptions{
    incremental true
    javaMaxHeapSize "4g"
}

defaultConfig {
        applicationId "..."
        minSdkVersion 14
        targetSdkVersion 22
        versionCode 1
        versionName "1.0"
        multiDexEnabled true
    }

buildTypes {

    release {
        minifyEnabled true
        proguardFiles getDefaultProguardFile(''proguard-android.txt''), ''proguard-rules.pro''
        signingConfig signingConfigs.release
    }

    debug {
        minifyEnabled false
        shrinkResources false
        proguardFiles getDefaultProguardFile(''proguard-android.txt''), ''proguard-rules.pro''
        signingConfig signingConfigs.debug
    }
}

Archivo de reglas de ProGuard.

# Add project specific ProGuard rules here.
# By default, the flags in this file are appended to flags specified
# in /Users/osayilgan/Development/Android/sdk/tools/proguard/proguard-android.txt
# You can edit the include path and order by changing the proguardFiles
# directive in build.gradle.
#
# For more details, see
#   http://developer.android.com/guide/developing/tools/proguard.html

# Add any project specific keep options here:

# If your project uses WebView with JS, uncomment the following
# and specify the fully qualified class name to the JavaScript interface
# class:
#-keepclassmembers class fqcn.of.javascript.interface.for.webview {
#   public *;
#}

-keepnames public class * extends io.realm.RealmObject
-keep class io.realm.** { *; }
-dontwarn javax.**
-dontwarn io.realm.**

Y aquí está el archivo proguard-android. Este es el predeterminado del SDK de Android.

# This is a configuration file for ProGuard.
# http://proguard.sourceforge.net/index.html#manual/usage.html

-dontusemixedcaseclassnames
-dontskipnonpubliclibraryclasses
-verbose

# Optimization is turned off by default. Dex does not like code run
# through the ProGuard optimize and preverify steps (and performs some
# of these optimizations on its own).
-dontoptimize
-dontpreverify
# Note that if you want to enable optimization, you cannot just
# include optimization flags in your own project configuration file;
# instead you will need to point to the
# "proguard-android-optimize.txt" file instead of this one from your
# project.properties file.

-keepattributes *Annotation*
-keep public class com.google.vending.licensing.ILicensingService
-keep public class com.android.vending.licensing.ILicensingService

# For native methods, see http://proguard.sourceforge.net/manual/examples.html#native
-keepclasseswithmembernames class * {
    native <methods>;
}

# keep setters in Views so that animations can still work.
# see http://proguard.sourceforge.net/manual/examples.html#beans
-keepclassmembers public class * extends android.view.View {
   void set*(***);
   *** get*();
}

# We want to keep methods in Activity that could be used in the XML attribute onClick
-keepclassmembers class * extends android.app.Activity {
   public void *(android.view.View);
}

# For enumeration classes, see http://proguard.sourceforge.net/manual/examples.html#enumerations
-keepclassmembers enum * {
    public static **[] values();
    public static ** valueOf(java.lang.String);
}

-keep class * implements android.os.Parcelable {
  public static final android.os.Parcelable$Creator *;
}

-keepclassmembers class **.R$* {
    public static <fields>;
}

# The support library contains references to newer platform versions.
# Don''t warn about those in case this app is linking against an older
# platform version.  We know about them, and they are safe.
-dontwarn android.support.**

Answer 1

Me tomó un tiempo entenderlo, pero, como había adivinado, todo se trataba de la configuración de Proguard.

Comencé a investigar las Advertencias en la Consola y me di cuenta de que Proguard no podía encontrar algunas de las Referencias. Así que agregarlos como -dontwarn to proguard configuration file resolvió el problema.

En mi caso, tuve que ignorar los paquetes de abajo;

-dontwarn java.lang.invoke**
-dontwarn org.apache.lang.**
-dontwarn org.apache.commons.**
-dontwarn com.nhaarman.**
-dontwarn se.emilsjolander.**