Proxies are very important because they allow you to distinguish between the sides of your program.
There are parts that you might want to implement only on the client, like GUI Drawing, Rendering of items, keybindings etc.
Then there's things that you ONLY want to do on the server. Like sending a message to the player. It wouldn't make sense to have the client send a message to itself.
Then there's finally some stuff you might want to send to both, like when the player picks up an item. That way the client and server are perfectly in synch.
I'm not sure what version you might be on. But in general you want to make a package with a ClientProxy, a ServerProxy class and a commonproxy class.
Your proxy classes simply define where stuff goes. they have the same pre-init, postinit and init your main class should have:
public class CommonProxy {
public void preInit(FMLPreInitializationEvent e) {
}
public void init(FMLInitializationEvent e) {
}
public void postInit(FMLPostInitializationEvent e) {
}
}
public class ServerProxy extends CommonProxy{
@Override
public void preInit(FMLPreInitializationEvent e) {
super.preInit(e);
}
@Override
public void init(FMLInitializationEvent e) {
super.init(e);
}
@Override
public void postInit(FMLPostInitializationEvent e) {
super.postInit(e);
}
}
(ClientProxy is the same but called Clientproxy)
Register these classes as proxies in your main class (Where your preinit, init etc. are registered) like so:
@SidedProxy(clientSide="package.clientproxy", serverSide="package.serverproxy")
public static CommonProxy proxy;
Since you already registered a static reference to your commonproxy and a bridge to your client and serverproxies by calling sidedproxy you can now call your commonproxy in the main methods. Add Main.proxy.preInit(e); to your Main preInit method like such:
@EventHandler
public void preInit(FMLPreInitializationEvent e) {
Main.proxy.preInit(e);
}
public static BarPacketHandler packetHandler;
@EventHandler
public void init(FMLInitializationEvent e) {
Main.proxy.init(e);
}
@EventHandler
public void postInit(FMLPostInitializationEvent e) {
Main.proxy.postInit(e);
}
Obviously these are all just basic, rough drafts that you'd have to adapt to your class. But if you know Java to any degree you should be able to figure out what I said (hopefully. English isn't my first language).
Now when you want a method in your client only, you add the registry/call to ClientProxy under the right place. CommonProxy will call everything that runs on both and ServerProxy runs on the server.