Fix error when no player in server

gradle.properties

@@ -34,7 +34,7 @@ mod_name=PlayerSync
 # The license of the mod. Review your options at https://choosealicense.com/. All Rights Reserved is the default.
 mod_license=GPL-3.0 license
 # The mod version. See https://semver.org/
-mod_version=2.1.2
+mod_version=2.1.3
 # The group ID for the mod. It is only important when publishing as an artifact to a Maven repository.
 # This should match the base package used for the mod sources.
 # See https://maven.apache.org/guides/mini/guide-naming-conventions.html

src/main/java/vip/fubuki/playersync/CommandInit.java

@@ -0,0 +1,28 @@
+package vip.fubuki.playersync;
+
+import com.mojang.brigadier.CommandDispatcher;
+import net.minecraft.commands.CommandSourceStack;
+import net.minecraft.commands.Commands;
+import net.minecraftforge.event.RegisterCommandsEvent;
+import net.minecraftforge.eventbus.api.SubscribeEvent;
+import net.minecraftforge.fml.common.Mod;
+import vip.fubuki.playersync.sync.chat.ChatSyncClient;
+
+@Mod.EventBusSubscriber()
+public class CommandInit {
+
+    @SubscribeEvent
+    public static void registerCommand(RegisterCommandsEvent event){
+        CommandDispatcher<CommandSourceStack> dispatcher=event.getDispatcher();
+        dispatcher.register(Commands.literal("playersync")
+                .requires(cs->cs.hasPermission(2))
+                .then(Commands.literal("reconnect")
+                        .executes(context -> {
+                            new ChatSyncClient().run();
+//                                  context.getSource().sendSuccess(()->MutableComponent.create(new TranslatableContents("playersync.command.reconnect")),true);
+                                    return 0;
+                                }
+                        ))
+        );
+    }
+}

src/main/java/vip/fubuki/playersync/sync/chat/ChatSyncClient.java

@@ -32,7 +32,9 @@ public class ChatSyncClient {
             while ((serverMessage = in.readLine()) != null) {
                 PlayerSync.LOGGER.info("Received message from chat server: " + serverMessage);
                 Component textComponents = Component.nullToEmpty(serverMessage);
-                playerList.broadcastSystemMessage(textComponents,false);
+                if(playerList!=null){
+                    playerList.broadcastSystemMessage(textComponents,false);
+                }
             }
         } catch (IOException e) {
             e.printStackTrace();
@@ -40,7 +42,7 @@ public class ChatSyncClient {
         }
     }
 
-    private static void reconnectClient() {
+    private void reconnectClient() {
         ChatSync.LOGGER.warn("TODO: implement reconnectClient()");
         //TODO
     }