Issue when starting Release APK (not in debug/staging)

[alissongodoi]

After compiling the app and installing it on the Android Emulator 6.0 it crashes with the following error on startup:

java.lang.InternalError: cannot instantiate DNSSDjava.lang.ClassNotFoundException: com.github.druk.dnssd.AppleDNSSD
                                                                           at com.b.a.a.h.<clinit>(Unknown Source)
                                                                           at com.b.a.a.b.<init>(Unknown Source)
                                                                           at com.b.a.a.b.<init>(Unknown Source)
                                                                           at com.b.a.a.c.<init>(Unknown Source)
                                                                           at com.yourock.digitaltv.coordinator.CoordinatorService.<clinit>(Unknown Source)
                                                                           at java.lang.Class.newInstance(Native Method)
                                                                           at android.app.ActivityThread.handleCreateService(ActivityThread.java:2859)
                                                                           at android.app.ActivityThread.-wrap4(ActivityThread.java)
                                                                           at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1427)
                                                                           at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                           at android.os.Looper.loop(Looper.java:148)
                                                                           at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                                           at java.lang.reflect.Method.invoke(Native Method)
                                                                           at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                           at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

This is the implementation settings at gradle:

    implementation 'com.github.andriydruk:dnssd:0.9.5'
    implementation('com.github.andriydruk:rxdnssd:0.9.5')
    implementation 'io.reactivex:rxjava:1.3.0'
    implementation 'io.reactivex:rxandroid:1.2.1'

In proguard rules I had the following which I removed:

# Removing references to RxDnssd
# -dontwarn com.github.druk.**

I guess it is falling into this piece of code being null?

String name = System.getProperty( "com.github.druk.dnssd.DNSSD" );

Observe that this just happens when I compile for Release. It is working ok for other releases. These are my proguard rules:

# Add project specific ProGuard rules here.
# By default, the flags in this file are appended to flags specified
# in /Users/alissongodoi/Library/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 *;
#}

# Uncomment this to preserve the line number information for
# debugging stack traces.
#-keepattributes SourceFile,LineNumberTable

# If you keep the line number information, uncomment this to
# hide the original source file name.
#-renamesourcefileattribute SourceFile

# Proguard configuration for Jackson 2.x (fasterxml package instead of codehaus package)
-keep class com.fasterxml.jackson.databind.ObjectMapper {
    public <methods>;
    protected <methods>;
}
-keep class com.fasterxml.jackson.databind.ObjectWriter {
    public ** writeValueAsString(**);
}
-keepnames class com.fasterxml.jackson.** { *; }
-dontwarn com.fasterxml.jackson.databind.**

#Proguard for okio
-dontwarn okhttp3.*
-dontwarn okio.**

#ProGuard for EventBus
-keepattributes *Annotation*
-keepclassmembers class ** {
    @org.greenrobot.eventbus.Subscribe <methods>;
}
-keep enum org.greenrobot.eventbus.ThreadMode { *; }

#Configuration for jodatime
#-keep class org.joda.** { *; }
-dontwarn org.joda.convert.FromString
-dontwarn org.joda.convert.ToString

# Removing references to RxDnssd
-dontwarn com.github.druk.**

#Retrofit ProGuard
# Platform calls Class.forName on types which do not exist on Android to determine platform.
-dontnote retrofit2.Platform
# Platform used when running on Java 8 VMs. Will not be used at runtime.
-dontwarn retrofit2.Platform$Java8
# Retain generic type information for use by reflection by converters and adapters.
-keepattributes Signature
# Retain declared checked exceptions for use by a Proxy instance.
-keepattributes Exceptions

# Retrofit Retan Classes that are Models
-keep class com.yourock.digitaltv.model.** { *; }

[alissongodoi]

I have noticed that the issue goes away when minify is disabled. I have no idea why minify is causing this issue in the release build.

[alissongodoi]

It looks like it solves the issue by forcing minify to not remove the druk classes

#Minify was removing the druk classes for some reason #Forcing it to stay in the release package. -dontwarn com.github.druk.** -keep class com.github.druk.** { *; }

[andriydruk]

@alissongodoi Proguard make obfuscation of all you classes. It's rename all of them to a.b.c.d.etc. You are not first person who face this problem #19.

Maybe I should ship AAR with proguard rules inside. I'm going to investigate if it's possible

[G00fY2]

@andriydruk: Should be possible with consumerProguardFiles. Otherwise I would recommend maybe put the rules in the readme (like in retrofit).

[skykelsey]

As mentioned by @G00fY2, you should be able to just add a file called consumer-proguard-rules.pro in the same directory as your build.gradle. Then, add this line in build.gradle in defaultConfig:

consumerProguardFiles 'consumer-proguard-rules.pro'

I can open a PR if you'd like.

[skykelsey]

The above proguard rules work, but they are overly broad. For my app, I noticed the following method counts on com.github.druk when using proguard to minify:

Without rules: 106 With rules: 394

I tried adding individual rules for each JNI reference, but I gave up. I would suggest moving all the JNI stuff into its own package so you can take care of it with a single proguard rule like -keep com.github.druk.dnssd.jni.** { *; } without needlessly keeping all the rest of the code.

[Abu-Abdullah]

i believe you need to keep rx.* as well:

-keep class com.github.druk.** { *; }
-keep class rx.** { *; }

[tmm1]

I can open a PR if you'd like.

Please do this.

[leohuangyi]

-keep class com.github.druk.dnssd.** { *; }

work well!