Reflection help

Hello,
I'm trying to send packets using Reflection so my plugin will be version independant. (Don't suggest ProtocolLib please, It's an awesome lib, but I don't want to use it, don't ask why I don't want to use it)
So what I did:

Code:java

 
Object packet = ReflectionUtil.getClass("Packet40EntityMetadata"); //reflectionutil is just a little class that has a set of utils.
//then set the values for the packet
Field a = packet.getClass().getDeclaredField("a");
a.setAccesible(true);
a.set(packet, player.getEntityId());
 

Now as you all, or some of you know, this packet requires 2 params . a = the entityId and b = getDataWatcher().c();

But I have no idea on how to set the 'b' field in the packet. I first need to invoke the "getDataWatcher" method and then, from within the datawatcher class invoke the "c" method and set that as the "b" field.
I know, this is not very well explained so here is the github link: https://github.com/Bukkit/mc-dev/blob/master/net/minecraft/server/Packet40EntityMetadata.java#L14

Don't start asking "whats your packet send method?" or "How did you obtain the EntityPlayer?" because I know I'm doing those things right. The only think I need to know is how I can set the "b" field to the correct thing.

Thanks.
(Sorry Icyene but since you're a reflection-pro? Mayeb you can help me?)

 

What you are doing is relatively simple. You already got part of it: you have the field reflection down. You just need to extend that knowledge to include methods, but its not a great leap.

I put together a simple code snippet to illustrate what you are trying to do (providing I understood your question correctly):

Code:Java

 
Object holder = ...; // This is the object that has the getDataWatcher method
Object packetHandle = ...; // Reference to the packet you created
Object watcherHandle = Reflection.declaredMethod("getDataWatcher").in(holder).invoke(); // This is a handle to the DataWatcher instance
Object c = Reflection.declaredMethod("c").in(watcherHandle).invoke(); // Get the return value from the c method
Reflection.field("b").in(packetHandle).set(c); // Set b to the gotten c
 

It uses a little one-file library I wrote a while back: ReflectionHelper, but the intent is clear and should be easy to separate from the helper class.

If my code doesn't work, or I missed something or misunderstood the question, don't hesitate to tag me.