fix: 添加难度选项 #2

test_import.json

@@ -2,6 +2,7 @@
   {
     "title": "Java中，以下哪个关键字用于定义接口？",
     "type": 1,
+    "level": 1,
     "answerA": "class",
     "answerB": "interface",
     "answerC": "extends",
@@ -9,9 +10,32 @@
     "rAnswer": "B",
     "score": 5
   },
+  {
+    "title": "以下哪个不是Java的基本数据类型？",
+    "type": 1,
+    "level": 1,
+    "answerA": "int",
+    "answerB": "String",
+    "answerC": "boolean",
+    "answerD": "double",
+    "rAnswer": "B",
+    "score": 5
+  },
+  {
+    "title": "Java中，main方法的正确写法是？",
+    "type": 1,
+    "level": 1,
+    "answerA": "public void main(String[] args)",
+    "answerB": "public static void main(String[] args)",
+    "answerC": "public static int main(String[] args)",
+    "answerD": "static void main(String args)",
+    "rAnswer": "B",
+    "score": 5
+  },
   {
     "title": "Spring框架的核心特性是什么？",
     "type": 1,
+    "level": 2,
     "answerA": "AOP面向切面编程",
     "answerB": "IOC控制反转",
     "answerC": "MVC设计模式",
@@ -19,26 +43,104 @@
     "rAnswer": "D",
     "score": 5
   },
+  {
+    "title": "MySQL中，以下哪个关键字用于删除表？",
+    "type": 1,
+    "level": 2,
+    "answerA": "DELETE",
+    "answerB": "DROP",
+    "answerC": "REMOVE",
+    "answerD": "CLEAR",
+    "rAnswer": "B",
+    "score": 5
+  },
+  {
+    "title": "以下哪个设计模式属于创建型模式？",
+    "type": 1,
+    "level": 2,
+    "answerA": "观察者模式",
+    "answerB": "单例模式",
+    "answerC": "策略模式",
+    "answerD": "装饰器模式",
+    "rAnswer": "B",
+    "score": 5
+  },
+  {
+    "title": "Redis支持的数据结构包括？",
+    "type": 1,
+    "level": 3,
+    "answerA": "String",
+    "answerB": "List",
+    "answerC": "Set",
+    "answerD": "以上都是",
+    "rAnswer": "D",
+    "score": 5
+  },
+  {
+    "title": "Java虚拟机（JVM）的主要组成部分包括？",
+    "type": 1,
+    "level": 3,
+    "answerA": "类加载器",
+    "answerB": "运行时数据区",
+    "answerC": "执行引擎",
+    "answerD": "以上都是",
+    "rAnswer": "D",
+    "score": 5
+  },
   {
     "title": "简述Java中Exception和Error的区别。",
     "type": 2,
-    "rAnswer": "Exception是程序可以处理的异常，通常由程序逻辑错误引起；Error是严重错误，如内存溢出，程序无法处理。",
+    "level": 1,
+    "rAnswer": "Exception是程序可以处理的异常，通常由程序逻辑错误引起，如NullPointerException；Error是严重错误，如OutOfMemoryError，程序通常无法处理。",
+    "score": 10
+  },
+  {
+    "title": "什么是面向对象编程的三大特性？",
+    "type": 2,
+    "level": 1,
+    "rAnswer": "封装：将数据和方法包装在一起；继承：子类继承父类的特性；多态：同一操作作用于不同对象产生不同行为。",
+    "score": 10
+  },
+  {
+    "title": "简述JDK、JRE和JVM的区别。",
+    "type": 2,
+    "level": 2,
+    "rAnswer": "JDK是Java开发工具包，包含JRE和开发工具；JRE是Java运行时环境，包含JVM和核心类库；JVM是Java虚拟机，负责字节码的执行。",
     "score": 10
   },
   {
     "title": "MySQL中，如何优化慢查询？",
     "type": 2,
-    "rAnswer": "1. 添加索引；2. 优化SQL语句；3. 使用EXPLAIN分析查询计划；4. 避免全表扫描；5. 适当分表分库。",
+    "level": 2,
+    "rAnswer": "1. 添加合适的索引；2. 优化SQL语句，避免全表扫描；3. 使用EXPLAIN分析查询计划；4. 优化表结构；5. 适当进行分表分库。",
     "score": 15
   },
   {
-    "title": "以下哪个不是Java的基本数据类型？",
-    "type": 1,
-    "answerA": "int",
-    "answerB": "String",
-    "answerC": "boolean",
-    "answerD": "double",
-    "rAnswer": "B",
-    "score": 5
+    "title": "解释Spring中的IOC和AOP概念。",
+    "type": 2,
+    "level": 2,
+    "rAnswer": "IOC（控制反转）是将对象的创建和管理交给Spring容器，降低耦合度；AOP（面向切面编程）是将横切关注点（如日志、事务）从业务逻辑中分离，提高代码复用性。",
+    "score": 15
+  },
+  {
+    "title": "什么是线程安全问题？如何解决？",
+    "type": 2,
+    "level": 3,
+    "rAnswer": "线程安全是指多个线程同时访问共享资源时可能出现数据不一致的问题。解决方法包括：1. synchronized关键字；2. ReentrantLock锁；3. 原子类；4. ThreadLocal；5. 使用线程安全的集合类。",
+    "score": 15
+  },
+  {
+    "title": "简述分布式事务的解决方案。",
+    "type": 2,
+    "level": 3,
+    "rAnswer": "1. 两阶段提交（2PC）：准备阶段和提交阶段；2. 三阶段提交（3PC）：增加了预提交阶段；3. TCC：Try-Confirm-Cancel；4. 本地消息表；5. 最大努力通知；6. Saga模式。",
+    "score": 15
+  },
+  {
+    "title": "什么是JVM的垃圾回收机制？",
+    "type": 2,
+    "level": 3,
+    "rAnswer": "垃圾回收是JVM自动管理内存的机制，主要回收堆内存中不再使用的对象。常用算法包括：标记-清除、标记-整理、复制算法、分代收集算法。垃圾收集器有Serial、Parallel、CMS、G1等。",
+    "score": 15
   }
 ]