How to make Proguard ignore external libraries?

Question

I want to use Proguard mainly for obfuscation reasons.

My problem is that I have three libraries, Twitter4J and two signpost libraries. These libraries caused errors when I tried to create an signed APK. To get over this I put the following in the proguard.config file...

-dontwarn org.apache.commons.codec.binary.** 
-dontwarn org.slf4j.** 
-dontwarn com.sun.syndication.io.**
-dontwarn com.sun.syndication.feed.synd.*   

While this got rid of the errors in the console, when i loaded my signed APK onto my mobile phone it instantly crashed. The DDMS said this was due to a class not found in Twitter4J.

Getting rid of the "dontwarns" above did not help. Neither did adding dontshrink dontoptimise.

I would like Proguard to completely ignore the libraries (as they are open source anyway). Is this possible?

Glottology

Answer 1

Try this:

-keep class javax.** { *; }
-keep class org.** { *; }
-keep class twitter4j.** { *; }

Cf post from @CaspNZ: Android Proguard with external jar

Wistful

Thanks a lot! I first ignored this post as I thought my errors would not be solved by this, but somehow it did. I just don't know the magic of proguard... – Abeyant

@Abeyant plz reply in android studio where to add these lines, either in 'proguard-project.txt' or 'proguard-rules.pro' – Scyphus

@ShirishHerwade just checked and I've put it in the proguard-rules.txt. Check your build.gradle for the correct file – Abeyant

Two asterisks don't compile anymore. Any other solutions? – Appoint

Answer 2

You should be able to add to the proguard.cfg the following lines to exclude all classes within a package (and subpackages)

-keep class org.apache.commons.codec.binary.**
-keep interface org.apache.commons.codec.binary.**
-keep enum org.apache.commons.codec.binary.**
-keep class org.slf4j.**
-keep interface org.slf4j.**
-keep enum org.slf4j.**
-keep class com.sun.syndication.io.**
-keep interface com.sun.syndication.io.**
-keep enum com.sun.syndication.io.**
-keep class com.sun.syndication.feed.synd.**
-keep interface com.sun.syndication.feed.synd.**
-keep enum com.sun.syndication.feed.synd.**

Disaccustom

Hi @Nic Strong, hanks for the reply. I added the code but when I tried to export the signed APK a lot of errors typically like "[2011-10-11 15:11:00 - canonV0003PRO] Warning: oauth.signpost.signature.OAuthMessageSigner: can't find referenced class org.apache.commons.codec.binary.Base64". Any other suggestions greatly appreciated. Mel – Glottology

Did you also add oauth.signpost.** to the list of packages to keep? – Disaccustom

@NicStrong plz reply in android studio where to add these lines, either in 'proguard-project.txt' or 'proguard-rules.pro' – Scyphus

Two asterisks don't compile anymore. Any other solutions? – Appoint

Answer 3

I'd like to add that you should sync your project with Gradle files after adding proguard rules, otherwise they may not work.

Tricotine