tablist

private static final Field fieldPlayers = ObfuscationReflectionHelper.findField(SPlayerListItemPacket.class, "field_179769_b");
    private static final Field fieldDisplayName = ObfuscationReflectionHelper.findField(AddPlayerData.class, "field_179965_e");

    @SubscribeEvent
    public void onLogin(PlayerEvent.PlayerLoggedInEvent event) {
        PlayerEntity player = event.getPlayer();

        if (player.getServer() != null) {
            for (ServerPlayerEntity players : player.getServer().getPlayerList().getPlayers()) {
                players.connection.sendPacket(new SPlayerListItemPacket(SPlayerListItemPacket.Action.ADD_PLAYER, players));

                try {
                    SPlayerListItemPacket packet = new SPlayerListItemPacket();
                    List<AddPlayerData> packetValue = (List<AddPlayerData>) fieldPlayers.get(packet);

                } catch (ClassCastException | IllegalAccessException e ) {
                    Logger.getLogger(e.getLocalizedMessage());
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        }
    }