fly on exercises

data/1.Java初阶/1.Java概述/6.Java的应用领域/config.json

-{
-  "node_id": "java-733ca772d4c14e94974c0fa98c41820b",
-  "keywords": [],
-  "children": [],
-  "export": [],
-  "title": "Java的应用领域"
-}
\ No newline at end of file

data/1.Java初阶/1.Java概述/7.Java API文档/config.json

-{
-  "node_id": "java-eefa4050fc314922a8df1b5f101dcae1",
-  "keywords": [],
-  "children": [],
-  "export": [],
-  "title": "Java API文档"
-}
\ No newline at end of file

data/1.Java初阶/1.Java概述/8.使用IDE/config.json

-{
-  "node_id": "java-ee4e218c826b4f5cb22150ce60a5880b",
-  "keywords": [],
-  "children": [],
-  "export": [],
-  "title": "使用IDE"
-}
\ No newline at end of file

data/3.Java高阶/2.Optional/1.Optional与Null/optional.json

@@ -3,5 +3,8 @@
   "author": "刘鑫",
   "source": "form.md",
   "notebook_enable": false,
-  "export": ["optional.json"]
+  "export": [
+    "optional.json"
+  ],
+  "exercise_id": "3065a850d8bc4ee1b10bf5cdcd78128b"
 }
\ No newline at end of file

data/3.Java高阶/2.Optional/2.一致性/optional.json

@@ -3,5 +3,8 @@
   "author": "刘鑫",
   "source": "form.md",
   "notebook_enable": false,
-  "export": ["optional.json"]
+  "export": [
+    "optional.json"
+  ],
+  "exercise_id": "e639c1be98854a59b128da0492cb1126"
 }
\ No newline at end of file

data/3.Java高阶/4.Java异步任务/1.为支持并发而不断演进的Java/config.json

-{
-  "node_id": "java-889e8043d080406fa4f505990615a20c",
-  "keywords": [],
-  "children": [
-    {
-      "其他的线程抽象：非嵌套方法调用": {
-        "keywords": [],
-        "children": [],
-        "node_id": "java-b0623f5f2fd04678aa56901d2eee493b",
-        "title": "其他的线程抽象：非嵌套方法调用"
-      }
-    },
-    {
-      "你希望线程为你带来什么": {
-        "keywords": [],
-        "children": [],
-        "node_id": "569d5e11c4fc5de7844053d9a733c5e8",
-        "title": "你希望线程为你带来什么"
-      }
-    }
-  ],
-  "export": [],
-  "title": "为支持并发而不断演进的Java"
-}
\ No newline at end of file

data/3.Java高阶/4.Java异步任务/2.同步及异步API/config.json

-{
-  "node_id": "java-ea102b3f32754119b4d16bcce54743b2",
-  "keywords": [],
-  "children": [
-    {
-      "Future风格的API": {
-        "keywords": [],
-        "children": [],
-        "node_id": "java-2311732fd9034ba68ae16842da51192e",
-        "title": "Future风格的API"
-      }
-    },
-    {
-      "反应式风格的API": {
-        "keywords": [],
-        "children": [],
-        "node_id": "569d5e11c4fc5de7844053d9a733c5e8",
-        "title": "反应式风格的API"
-      }
-    },
-    {
-      "有害的睡眠及其他阻塞式操作": {
-        "keywords": [],
-        "children": [],
-        "node_id": "569d5e11c4fc5de7844053d9a733c5e8",
-        "title": "有害的睡眠及其他阻塞式操作"
-      }
-    },
-    {
-      "如何使用异步API进行异常处理": {
-        "keywords": [],
-        "children": [],
-        "node_id": "569d5e11c4fc5de7844053d9a733c5e8"
-      }
-    }
-  ],
-  "export": [],
-  "title": "同步及异步API"
-}
\ No newline at end of file

data/tree.json

@@ -48,27 +48,6 @@
                       "children": []
                     }
                   },
-                  {
-                    "Java的应用领域": {
-                      "node_id": "java-733ca772d4c14e94974c0fa98c41820b",
-                      "keywords": [],
-                      "children": []
-                    }
-                  },
-                  {
-                    "Java API文档": {
-                      "node_id": "java-eefa4050fc314922a8df1b5f101dcae1",
-                      "keywords": [],
-                      "children": []
-                    }
-                  },
-                  {
-                    "使用IDE": {
-                      "node_id": "java-ee4e218c826b4f5cb22150ce60a5880b",
-                      "keywords": [],
-                      "children": []
-                    }
-                  },
                   {
                     "测试开发环境": {
                       "node_id": "java-6d12bdbdeb7144aeb3649d50e0f06007",