gistfile1.txt

class MsgSend
{
    /**
     * Dynamically invoke a method, much like Objective-C message sending.
     *
     * This will ignore access restrictions, much like in Objective-C.
     * Invoking private methods on other classes may cause harmful side-effects.
     *
     * @param object The object to "pass the message" to. If this is null,
     *      the result is always null.
     * @param methodName String specifiying the name of the method, similar to
     *      Objective-C's selectors.
     * @throws RuntimeException Exception thrown if no method exists for the
     *      specified arguments.
     */
    public static Object msgSend(Object object, String methodName, Object... args)
    {
        if (object == null) {
            return null;
        }

        Object returnObject = null;
        Method method = null;
        try {
            Class[] argumentClasses = new Class[args.length];
            for (int i = 0; i < args.length; i++) {
                argumentClasses[i] = args[i].getClass();
            }
            method = object.getClass().getDeclaredMethod(methodName, argumentClasses);
        } catch (NoSuchMethodException ex) {
            throw new RuntimeException(ex);
        }

        // Enable bypassing of access restrictions.
        method.setAccessible(true);

        try {
            returnObject = method.invoke(object, args);
        } catch (IllegalAccessException ex) {
            // Should not happen due to access bypass.
            ex.printStackTrace();
            return null;
        } catch (InvocationTargetException ex) {
            ex.printStackTrace();
            return null;
        }

        return returnObject;
    }
}