更新 src/main/java/cn/edu/zust/dubbo/ SingletonPattern.java/Singleton.java

src/main/java/cn/edu/zust/dubbo/ SingletonPattern.java/Singleton.java

@@ -1,9 +1,10 @@
 package cn.edu.zust.dubbo;
 
 public class SingletonPattern {
+    // 单例模式实现示例
     private static SingletonPattern instance;
     
-    private SingletonPattern() {}
+    private SingletonPattern() {}  // 私有构造函数
     
     public static SingletonPattern getInstance() {
         if (instance == null) {
@@ -16,6 +17,7 @@ public class SingletonPattern {
         System.out.println("Singleton Pattern Demo");
     }
     
+    // 程序入口
     public static void main(String[] args) {
         SingletonPattern singleton = SingletonPattern.getInstance();
         singleton.showMessage();