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

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

@@ -0,0 +1,23 @@
+package cn.edu.zust.dubbo;
+
+public class SingletonPattern {
+    private static SingletonPattern instance;
+    
+    private SingletonPattern() {}
+    
+    public static SingletonPattern getInstance() {
+        if (instance == null) {
+            instance = new SingletonPattern();
+        }
+        return instance;
+    }
+    
+    public void showMessage() {
+        System.out.println("Singleton Pattern Demo");
+    }
+    
+    public static void main(String[] args) {
+        SingletonPattern singleton = SingletonPattern.getInstance();
+        singleton.showMessage();
+    }
+}