调整格式

docs/LearningExperience/DesignPattern/从Spring及Mybatis框架源码中学习设计模式(创建型).md

@@ -37,12 +37,12 @@ public class Singleton3 {
     
     public static Singleton3 getInstance(){
         if(instance == null){
-        synchronized(Singleton3.class){
+            synchronized(Singleton3.class){
-            if(instance == null){
+                if(instance == null){
-                instance = new Singleton3();
+                    instance = new Singleton3();
+                }
             }
         }
-    }
         return instance;
     }
 }