How to check if class exists somewhere in package?

Question

I\'m currently dealing with a particular issue with my paid application. Internally it contains a licensing check. The app is patched by hackers by modifying the app apk/j

Answer 1

How does it get loaded if it's a random class in a random package?

That being said, see http://download.oracle.com/javase/6/docs/api/java/lang/System.html#getProperties%28%29 and java.class.path. For normal java apps, you have to walk the classpath and then search the entries (for jars) or directories (for .class files). But in a container-class-loader environment, this will fail to work (and I'm not sure how that applies to an android environment).

Answer 2

Not sure about android but in standard JDK you would do something like this:

try {
 Class.forName( "your.fqdn.class.name" );
} catch( ClassNotFoundException e ) {
 //my class isn't there!
}

Answer 3

You can use

public static Class<?> forName (String className)

and check the ClassNotFoundException

http://developer.android.com/reference/java/lang/Class.html#forName%28java.lang.String%29

Answer 4

Here is what I used in Android - standard Java:

public boolean isClass(String className) {
    try  {
        Class.forName(className);
        return true;
    }  catch (ClassNotFoundException e) {
        return false;
    }
}

Implementation example:

if (isClass("android.app.ActionBar")) {
    Toast.makeText(getApplicationContext(), "YES", Toast.LENGTH_SHORT).show();
}