How to Duck type a Java object using Groovy or some other JVM language

Question

My problem is that I am trying to interop with a Java app whose jar file contains obfuscated byte code. The app releases updates ever month or so, and when they do a release, most of the class and method names change.

Thus, the method proposed here:

http://rickyclarkson.blogspot.com/2006/07/duck-typing-in-java-and-no-reflection.html

or

Simulating duck typing in Java

won't work in my solution because because I would have to update the interfaces by hand each time.

What I do have however is an automatically generated (for the most part) mapping from deobfuscated class name <-> obfuscated class name by means of parsing the class files for calls to debug logging calls in the form of:

logger.log(severity, "ClassName", "MethodName() has some error")

What I generate is something like this:

public final static String MyRealName = "someObfuscatedName".
public final static String MyRealName_myCoolMethod = "someMethodName".

I have a fairly decent solution for interacting with objects of "myRealName" via the reflection API and simply proxy objects that implement a subset of functionality of the object it is proxying. Somewhat like this:

class MyRealName {
    private Object backingObject;

    public MyRealName(Object o) { backingObject = o;}

    public void myCoolMethod() { 
        return getFieldValue(backingObject
        , DeobNames.MyRealName_myCoolMethod);
    }
}

However, the problem arises when I want to test my code in the absence of the obfuscated app from running - startup time and setup could take several minutes whereas I want test verification to be a couple of seconds.

What I am looking for is some way of easily adapting my tests to accommodate the frequently changing class names that my code depends upon.

I was intrigued by the power of tools like JMockit, etc in that they were able to automatically generate mock objects for me, I'm hoping to be able to have some thin layer that will enable to still have the majority of my mocks generated quite easily vs having to manually write everything, every update.

Answer 1

If you are running the code from Java, I don't think this is possible.

However if you are running the code with Groovy then you can use Groovy's methodMissing

See: http://groovy.codehaus.org/Using+methodMissing+and+propertyMissing