Obfuscation with Proguard GUI keeping class without config file
<p>I am obfuscating my Java code and I am using Proguard 5.2.1. However, while using the GUI, there is a warning that came up:</p>

<pre><code>ProGuard, version 5.2.1
Reading program jar [/root/Desktop/ACGPlain.jar]
Reading library jar [/usr/lib/jvm/java-7-openjdk-amd64/jre/lib/rt.jar]
Warning: connection.HttpURLClient: can't find referenced class javax.crypto.SecretKey
Warning: connection.HttpURLClient: can't find referenced class javax.crypto.SecretKey
Warning: connection.HttpURLClient: can't find referenced class javax.crypto.SecretKey
Warning: connection.HttpURLClient: can't find referenced class javax.crypto.SecretKey
Warning: connection.HttpURLClient: can't find referenced class javax.crypto.SecretKey
Warning: there were 5 unresolved references to classes or interfaces.
         You may need to add missing library jars or update their versions.
         If your code works fine without the missing classes, you can suppress
         the warnings with '-dontwarn' options.
         (http://proguard.sourceforge.net/manual/troubleshooting.html#unresolvedclass)
Please correct the above warnings first.
</code></pre>

<p>I have tried to run it on the command line with the <code>-dontwarn</code>options and the obfuscation did not work. I have tried the following too:</p>

<pre><code>java -jar proguard.jar -injar /root/Desktop/ACGPlain.jar -outjar /root/Desktop/ACGOB.jar -keepclass javax.crypto.SecretKey
</code></pre>

<p>Is there a way to stop proguard from hiding the javax.crypto.SecretKey class? I am looking for a GUI solution and not through the configuration file. My java code is not for android and is a program to secure transfers between the server and client.</p>