更新插件时检测在线玩家，如果有玩家则不会更新。

修复 /tlib iteminfo 命令的一些语法错误。

src/main/java/me/skymc/taboolib/commands/TabooLibMainCommand.java

@@ -12,6 +12,7 @@ import me.skymc.taboolib.commands.taboolib.*;
 import me.skymc.taboolib.fileutils.FileUtils;
 import me.skymc.taboolib.inventory.ItemUtils;
 import me.skymc.taboolib.other.NumberUtils;
+import me.skymc.taboolib.player.PlayerUtils;
 import me.skymc.taboolib.plugin.PluginUtils;
 import me.skymc.taboolib.update.UpdateTask;
 import org.bukkit.Bukkit;
@@ -807,6 +808,11 @@ public class TabooLibMainCommand extends BaseMainCommand {
 
                 @Override
                 public void run() {
+                    if (PlayerUtils.getOnlinePlayers().size() > 0) {
+                        TLocale.sendTo(sender, "COMMANDS.TABOOLIB.UPDATEPLUGIN.PLAYER-ONLINE");
+                        return;
+                    }
+
                     String url = Strings.replaceWithOrder("https://github.com/Bkm016/TabooLib/releases/download/{0}/TabooLib-{0}.jar", UpdateTask.getNewVersion());
                     TLocale.sendTo(sender, "COMMANDS.TABOOLIB.UPDATEPLUGIN.UPDATE-START", url);
 

src/main/java/me/skymc/taboolib/itemnbtapi/NBTCompound.java

@@ -190,7 +190,7 @@ public class NBTCompound {
     }
     
     public String asNBTString(){
-        return getCompound().toString();
+        return getCompound() == null ? "" : getCompound().toString();
     }
 
 }

src/main/java/me/skymc/taboolib/player/PlayerUtils.java

@@ -1,11 +1,15 @@
 package me.skymc.taboolib.player;
 
+import com.google.common.collect.ImmutableList;
 import org.bukkit.Bukkit;
 import org.bukkit.GameMode;
 import org.bukkit.block.Block;
 import org.bukkit.entity.Player;
 import org.bukkit.inventory.ItemStack;
 
+import java.lang.reflect.Method;
+import java.util.Collection;
+import java.util.Collections;
 import java.util.HashSet;
 
 /**
@@ -13,6 +17,30 @@ import java.util.HashSet;
  */
 public class PlayerUtils {
 
+    private static boolean setup;
+    private static boolean useReflection;
+    private static Method oldGetOnlinePlayersMethod;
+
+    public static Collection<? extends Player> getOnlinePlayers() {
+        try {
+            if (!setup) {
+                oldGetOnlinePlayersMethod = Bukkit.class.getDeclaredMethod("getOnlinePlayers");
+                if (oldGetOnlinePlayersMethod.getReturnType() == Player[].class) {
+                    useReflection = true;
+                }
+                setup = true;
+            }
+            if (!useReflection) {
+                return Bukkit.getOnlinePlayers();
+            } else {
+                Player[] playersArray = (Player[]) oldGetOnlinePlayersMethod.invoke(null);
+                return ImmutableList.copyOf(playersArray);
+            }
+        } catch (Exception e) {
+            return Collections.emptyList();
+        }
+    }
+
     /**
      * 获取目标方块
      *

src/main/resources/lang/zh_CN.yml

@@ -239,6 +239,7 @@ COMMANDS:
       UPDATE-NOT-FOUND: '&8[&3&lTabooLib&8] &7插件已是最新版, 无需更新!'
       UPDATE-NOT-SUPPORT: '&8[&3&lTabooLib&8] &4您的服务器不支持在线更新!'
       FILE-NOT-FOUND: '&8[&3&lTabooLib&8] &4尚未寻找到插件文件'
+      PLAYER-ONLINE: '&8[&3&lTabooLib&8] &4服务器有玩家在线无法更新插件.'
       UPDATE-START: '&8[&3&lTabooLib&8] &7开始下载:&f {0}'
       UPDATE-SUCCESS: '&8[&3&lTabooLib&8] &7最新版下载完成, 服务器即将重启!'
     JAVASHELL: