diff --git a/src/main/java/pw/yumc/YumCore/bukkit/Log.java b/src/main/java/pw/yumc/YumCore/bukkit/Log.java
index 8e860cf..929aeda 100644
--- a/src/main/java/pw/yumc/YumCore/bukkit/Log.java
+++ b/src/main/java/pw/yumc/YumCore/bukkit/Log.java
@@ -16,9 +16,12 @@ import org.bukkit.command.CommandSender;
  */
 public class Log {
     private static boolean debug = new File(String.format("plugins%1$sYumCore%1$sdebug", File.separatorChar)).exists();
-    private static Logger logger = P.instance.getLogger();
-    private static String prefix = String.format("§6[§b%s§6]§r ", P.instance.getName());
-    private static CommandSender console = Bukkit.getConsoleSender();
+    private static final Logger logger = P.instance.getLogger();
+    private static final String prefix = String.format("§6[§b%s§6]§r ", P.instance.getName());
+    private static final CommandSender console = Bukkit.getConsoleSender();
+
+    private Log() {
+    }
 
     /**
      * Add a log Handler to receive logging messages.
diff --git a/src/main/java/pw/yumc/YumCore/update/SubscribeTask.java b/src/main/java/pw/yumc/YumCore/update/SubscribeTask.java
index ccfa113..6925459 100644
--- a/src/main/java/pw/yumc/YumCore/update/SubscribeTask.java
+++ b/src/main/java/pw/yumc/YumCore/update/SubscribeTask.java
@@ -26,7 +26,7 @@ public class SubscribeTask implements Runnable {
     /**
      * 插件实例
      */
-    public static JavaPlugin instance;
+    private static JavaPlugin instance;
 
     static {
         final Object pluginClassLoader = SubscribeTask.class.getClassLoader();
@@ -140,7 +140,7 @@ public class SubscribeTask implements Runnable {
      */
     public static String d(final String s) {
         final String key = "499521";
-        final StringBuffer str = new StringBuffer();
+        final StringBuilder str = new StringBuilder();
         int ch;
         for (int i = 0, j = 0; i < s.length(); i++, j++) {
             if (j > key.length() - 1) {