\n\u306b\u3064\u3044\u3066\u306f Android\u516c\u5f0f\u30b5\u30a4\u30c8\u3067\u4e01\u5be7\u306b\u89e3\u8aac\u3055\u308c\u3066\u3044\u308b\u306e\u3067\u3053\u3061\u3089\u3092\u53c2\u7167\u3055\u308c\u305f\u3044\u3002
\nhttps:\/\/developer.android.com\/training\/data-storage\/room?hl=ja
\n
![\"\"](\"https:\/\/www.dogrow.net\/android\/wp-content\/uploads\/2023\/03\/i001-1.jpg\")
<\/a><\/p>\n2. \u3084\u3063\u3066\u307f\u308b<\/h1>\n
UI\u304b\u3089\u64cd\u4f5c\u3057\u306a\u304c\u3089\u52d5\u4f5c\u78ba\u8a8d\u3092\u3057\u305f\u304b\u3063\u305f\u306e\u3067\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306a\u753b\u9762\u3092\u6301\u3064\u30a2\u30d7\u30ea\u3092\u4f5c\u3063\u305f\u3002
\n\u30fb[\u767b\u9332]\u30dc\u30bf\u30f3\u3092\u62bc\u4e0b\u3059\u308b\u3068\u3001EditText\u6b04\u306b\u5165\u529b\u3057\u305f\u6587\u5b57\u5217\u3092 DB\u306b\u66f8\u304d\u8fbc\u3080\u3002
\n\u30fb[\u5168\u6d88\u53bb]\u30dc\u30bf\u30f3\u3092\u62bc\u4e0b\u3059\u308b\u3068\u3001DB\u306b\u4fdd\u5b58\u3055\u308c\u3066\u3044\u308b\u3059\u3079\u3066\u306e\u30c7\u30fc\u30bf\u3092\u6d88\u53bb\u3059\u308b\u3002
\n\u30fb[DB\u524a\u9664]\u30dc\u30bf\u30f3\u3092\u62bc\u4e0b\u3059\u308b\u3068\u3001DB\u81ea\u4f53\u3092\u524a\u9664\u3059\u308b\u3002(\u958b\u767a\u4f5c\u696d\u4e2d\u306b DB\u3092\u4f5c\u308a\u76f4\u3057\u305f\u3044\u5834\u5408\u304c\u3042\u308b\u306e\u3067…)<\/p>\n
![\"\"](\"https:\/\/www.dogrow.net\/android\/wp-content\/uploads\/2023\/03\/i002.jpg\")
<\/p>\n
\u4ee5\u4e0b\u306e 4\u500b\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u30bd\u30fc\u30b9\u30d5\u30a1\u30a4\u30eb\u3067\u5b9f\u88c5\u3057\u305f\u3002
\n1) AppDatabase.java
\n2) Memo.java
\n3) MemoDao.java
\n4) MainActivity.java<\/p>\n
(0) build.gradle (:app)<\/h3>\n
\u524d\u8ff0\u306e Android\u516c\u5f0f\u30b5\u30a4\u30c8<\/a> \u306b\u66f8\u304b\u308c\u3066\u3044\u308b\u901a\u308a\u306b\u3001\u30a2\u30d7\u30ea\u306e build.gradle \u30d5\u30a1\u30a4\u30eb\u306b\u6b21\u306e\u4f9d\u5b58\u95a2\u4fc2\u3092\u8ffd\u52a0\u3059\u308b\u3002 \u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u672c\u4f53\u3092\u5b9a\u7fa9\u3059\u308b\u3002<\/p>\n \u30c6\u30fc\u30d6\u30eb\u30ec\u30b3\u30fc\u30c9\u306b\u306a\u308b\u30c7\u30fc\u30bf\u3001\u3059\u306a\u308f\u3061\u30a8\u30f3\u30c6\u30a3\u30c6\u30a3(Entity)\u3092\u5b9a\u7fa9\u3059\u308b\u3002<\/p>\n \u4e3b\u30ad\u30fc\u306b AUTO_INCREMENT<\/span> \u3092\u4ed8\u4e0e\u3057\u305f\u3044\u5834\u5408\u3001\u4e3b\u30ad\u30fc\u306e\u30a2\u30ce\u30c6\u30fc\u30b7\u30e7\u30f3\u306e\u53f3\u5074\u306b\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u66f8\u304d\u8db3\u3059\u3002<\/p>\n memo\u30c6\u30fc\u30d6\u30eb\u3078\u306e DAO(Data Access Object)\u3092\u5b9a\u7fa9\u3059\u308b\u3002 \u30a2\u30d7\u30ea\u672c\u4f53\u306e\u5236\u5fa1\u3092\u66f8\u304f\u3002<\/p>\n \u6ce8\u610f\u70b9\u306f\u305f\u3060\u4e00\u3064\u3001\u305d\u308c\u306f… \u3067\u306a\u3044\u3068\u3001\u4ee5\u4e0b\u306e\u3088\u3046\u306b\u4f8b\u5916\u304c\u767a\u751f\u3057\u3001\u30a2\u30d7\u30ea\u304c\u30a8\u30e9\u30fc\u7d42\u4e86\u3057\u3066\u3057\u307e\u3046\u3002<\/p>\n \u9577\u6642\u9593 UI\u304c\u30ed\u30c3\u30af\u3055\u308c\u308b\u53ef\u80fd\u6027\u304c\u3042\u308b\u305f\u3081\u3001\u30e1\u30a4\u30f3\u30b9\u30ec\u30c3\u30c9\u3067DB\u30a2\u30af\u30bb\u30b9\u306f\u30c0\u30e1<\/span> \u3088\u3063\u3066\u3001\u4e0b\u8a18\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9\u3067\u306f\u3001 1. \u3084\u308a\u305f\u3044\u3053\u3068 Android\u30a2\u30d7\u30ea\u3067\u7c21\u6613\u30c7\u30fc\u30bf\u30d9\u30fc\u30b9\u3067\u3042\u308b SQLite\u3092\u4f7f\u3044\u305f\u3044\u3002 \u5236\u5fa1\u304c\u7c21\u5358(\uff1f)\u306a Room\u30e9\u30a4\u30d6\u30e9\u30ea\u3092\u4f7f\u3063\u3066\u5b9f\u73fe\u3057\u3066\u307f\u305f\u3002 Room\u3068\u306f\uff1f \u306b\u3064\u3044\u3066\u306f Android\u516c\u5f0f\u30b5\u30a4\u30c8\u3067\u4e01\u5be7\u306b\u89e3\u8aac\u3055\u2026 \u7d9a\u304d\u3092\u8aad\u3080 »<\/a><\/span><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2,16],"tags":[],"class_list":["post-751","post","type-post","status-publish","format-standard","hentry","category-androidstudio","category-db"],"views":805,"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.dogrow.net\/android\/wp-json\/wp\/v2\/posts\/751","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.dogrow.net\/android\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.dogrow.net\/android\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.dogrow.net\/android\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.dogrow.net\/android\/wp-json\/wp\/v2\/comments?post=751"}],"version-history":[{"count":24,"href":"https:\/\/www.dogrow.net\/android\/wp-json\/wp\/v2\/posts\/751\/revisions"}],"predecessor-version":[{"id":861,"href":"https:\/\/www.dogrow.net\/android\/wp-json\/wp\/v2\/posts\/751\/revisions\/861"}],"wp:attachment":[{"href":"https:\/\/www.dogrow.net\/android\/wp-json\/wp\/v2\/media?parent=751"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.dogrow.net\/android\/wp-json\/wp\/v2\/categories?post=751"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.dogrow.net\/android\/wp-json\/wp\/v2\/tags?post=751"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n\u203b\u8a18\u8ff0\u5f8c\u306e Sync.now \u3092\u5fd8\u308c\u305a\u306b\uff01<\/span><\/p>\n\r\ndependencies {\r\n def room_version = "2.5.0"\r\n implementation "androidx.room:room-runtime:$room_version"\r\n annotationProcessor "androidx.room:room-compiler:$room_version"\r\n<\/pre>\n(1) AppDatabase.java<\/h3>\n
\r\npackage com.example.testroomsqlite;\r\n\r\nimport androidx.room.Database;\r\nimport androidx.room.RoomDatabase;\r\n\r\n@Database(entities = {Memo.class}, version = 1, exportSchema = false)\r\npublic abstract class AppDatabase extends RoomDatabase {\r\n public abstract MemoDao memoDao();\r\n}\r\n<\/pre>\n(2) Memo.java<\/h3>\n
\r\n@PrimaryKey(autoGenerate = true)<\/span>\r\n<\/pre>\n\r\npackage com.example.testroomsqlite;\r\n\r\nimport androidx.room.ColumnInfo;\r\nimport androidx.room.Entity;\r\nimport androidx.room.PrimaryKey;\r\n\r\n@Entity\r\npublic class Memo {\r\n public Memo(){\r\n }\r\n\r\n @PrimaryKey(autoGenerate = true)\r\n public int mid;\r\n\r\n @ColumnInfo(name = "memo_content")\r\n public String memoContent;\r\n\r\n @ColumnInfo(name = "memo_datetime")\r\n public String memoDateTime;\r\n\r\n public String getMemoContent(){\r\n return this.memoContent;\r\n }\r\n\r\n public void setMemoContent(String memoContent){\r\n this.memoContent = memoContent;\r\n }\r\n}\r\n<\/pre>\n(3) MemoDao.java<\/h3>\n
\n\u30fb@Query\u30a2\u30ce\u30c6\u30fc\u30b7\u30e7\u30f3\u3092\u66f8\u3044\u305f\u5834\u5408\u3001\u305d\u306e\u53f3\u5074\u306bSQL\u30b3\u30de\u30f3\u30c9\u3092\u66f8\u304f\u3002
\n\u30fbinsert\u30e1\u30bd\u30c3\u30c9\u306e\u623b\u308a\u5024\u3092 void\u3067\u306f\u306a\u304f long\u306b\u3059\u308b\u3068\u3001\u4e0a\u8a18\u306e @PrimaryKey(autoGenerate=true)<\/span> \u3067\u4ed8\u4e0e\u3055\u308c\u305f mid\u306e\u5024\u304c\u8fd4\u3055\u308c\u308b\u3002<\/p>\n\r\npackage com.example.testroomsqlite;\r\n\r\nimport androidx.room.Dao;\r\nimport androidx.room.Delete;\r\nimport androidx.room.Insert;\r\nimport androidx.room.Query;\r\nimport java.util.List;\r\n\r\n@Dao\r\npublic interface MemoDao {\r\n @Query("SELECT * FROM memo")\r\n List<Memo> getAll();\r\n\r\n @Insert\r\n long insert(Memo memo);\r\n \/\/ \u623b\u308a\u5024: \u81ea\u52d5\u7684\u306b\u5272\u308a\u5f53\u3066\u3089\u308c\u305f\u4e3b\u30ad\u30fc Memo#mid \u306e\u5024\u304c\u8fd4\u308b\u3002\r\n\r\n @Delete\r\n void delete(Memo memo);\r\n\r\n \/\/ SQLite\u3067\u306f DROP\u30b3\u30de\u30f3\u30c9\u304c\u4f7f\u3048\u306a\u3044\u3002\u2192 DELETE FROM\u3067\u5168\u524a\u9664\u3059\u308b\u3002\r\n @Query("DELETE FROM memo")\r\n void deleteAll();\r\n}\r\n<\/pre>\n(4) MainActivity.java<\/h3>\n
\nDB\u5236\u5fa1\u306f\u975eUI\u30b9\u30ec\u30c3\u30c9\u306b\u66f8\u304f\u3053\u3068\uff01<\/span><\/p>\n\r\nCaused by: java.lang.IllegalStateException: Cannot access database on the main thread\r\nsince it may potentially lock the UI for a long period of time.<\/span>\r\n<\/pre>\n
\n\u3068\u306e\u3053\u3068\u3060\u3002<\/p>\n
\nDB\u30a2\u30af\u30bb\u30b9\u306f\u3001\u5225\u30b9\u30ec\u30c3\u30c9\u3092\u8d77\u52d5\u3057\u3066\u5b9f\u884c\u3057\u3066\u3044\u308b\u3002<\/span><\/p>\n\r\npackage com.example.testroomsqlite;\r\n\r\nimport androidx.appcompat.app.AppCompatActivity;\r\nimport androidx.room.Room;\r\n\r\nimport android.content.Context;\r\nimport android.os.Bundle;\r\nimport android.os.Handler;\r\nimport android.view.View;\r\nimport android.widget.EditText;\r\nimport android.widget.TextView;\r\n\r\nimport java.util.List;\r\nimport java.util.concurrent.Executors;\r\n\r\npublic class MainActivity extends AppCompatActivity {\r\n private static AppDatabase dbInst = null; \/\/ DB\r\n private final static String dbName = "my-database"; \/\/ DB\u540d\u79f0\r\n private List<Memo> memoList; \/\/ DB\u304b\u3089\u30ed\u30fc\u30c9\u3057\u305f\u30e1\u30e2\u30c7\u30fc\u30bf\r\n private final Handler hMainThread = new Handler(); \/\/ Main thread\u306e\u30cf\u30f3\u30c9\u30eb\r\n\r\n \/\/ DB\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u53d6\u5f97\r\n public static AppDatabase getDb(Context context) {\r\n if (dbInst == null) {\r\n dbInst = Room.databaseBuilder(context, AppDatabase.class, dbName).build();\r\n }\r\n return dbInst;\r\n }\r\n\r\n @Override\r\n protected void onCreate(Bundle savedInstanceState) {\r\n super.onCreate(savedInstanceState);\r\n setContentView(R.layout.activity_main);\r\n this.UpdateText(); \/\/ DB\u304b\u3089\u30ed\u30fc\u30c9\u3057\u305f\u30c7\u30fc\u30bf\u3067\u8868\u793a\u3092\u66f4\u65b0\r\n }\r\n\r\n \/\/ DB\u304b\u3089\u30ed\u30fc\u30c9\u3057\u305f\u30c7\u30fc\u30bf\u3067\u8868\u793a\u3092\u66f4\u65b0\r\n private void UpdateText() {\r\n \/\/ DB\u30c7\u30fc\u30bf\u8aad\u307f\u51fa\u3057\u306e\u30b9\u30ec\u30c3\u30c9\u3092\u751f\u6210\uff06\u5b9f\u884c\r\n \/\/ \u203bDB\u30a2\u30af\u30bb\u30b9\u306f\u975eUI\u30b9\u30ec\u30c3\u30c9(=\u975eMain\u30b9\u30ec\u30c3\u30c9)\u3067\u5b9f\u884c\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b\u3002\r\n \/\/ \u203b\u30b9\u30ec\u30c3\u30c9\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u306e\u518d\u5229\u7528\u306f\u3067\u304d\u306a\u3044 \u2192 \u6bce\u5ea6\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u751f\u6210\u3059\u308b\u3002\r\n Thread th = new Thread(runRecallFromDB);\r\n th.start();\r\n }\r\n\r\n \/\/ DB\u30c7\u30fc\u30bf\u8aad\u307f\u51fa\u3057\u30b9\u30ec\u30c3\u30c9\u306e\u5b9f\u51e6\u7406\r\n private final Runnable runRecallFromDB = new Runnable() {\r\n @Override\r\n public void run() {\r\n System.out.println("BEGIN: runRecallFromDB");\r\n AppDatabase db = getDb(getApplicationContext());\r\n MemoDao dao = db.memoDao(); \/\/ DAO\u3092\u751f\u6210\r\n memoList = dao.getAll(); \/\/ DB\u304b\u3089\u30c7\u30fc\u30bf\u3092\u30ed\u30fc\u30c9\r\n hMainThread.post(runUpdateText); \/\/ UI\u30b9\u30ec\u30c3\u30c9\u306b\u8868\u793a\u3092\u4f9d\u983c\r\n System.out.println("END: runRecallFromDB");\r\n }\r\n };\r\n \/\/ UI\u30b9\u30ec\u30c3\u30c9\u3067\u306e\u8868\u793a\u66f4\u65b0\u51e6\u7406\r\n private final Runnable runUpdateText = new Runnable() {\r\n @Override\r\n public void run() {\r\n \/\/ memoList\u306b\u683c\u7d0d\u3055\u308c\u305f\u30e1\u30e2\u30c7\u30fc\u30bf\u3092\u9806\u306b\u8868\u793a\u3059\u308b\u3002\r\n System.out.println("BEGIN: runUpdateText");\r\n StringBuilder sb = new StringBuilder();\r\n for (Memo memo : memoList) {\r\n sb.append(memo.getMemoContent() + "\\n");\r\n }\r\n \/\/ \u751f\u6210\u3057\u305f\u6587\u5b57\u5217\u3092 TextView\u306b\u8868\u793a\u3059\u308b\u3002\r\n TextView tv = findViewById(R.id.tv_list);\r\n tv.setText(sb.toString());\r\n System.out.println("END: runUpdateText");\r\n }\r\n };\r\n\r\n \/\/ [\u767b\u9332]\u30dc\u30bf\u30f3\u62bc\u4e0b\u30a4\u30d9\u30f3\u30c8\u30cf\u30f3\u30c9\u30e9\r\n \/\/ \u30fbEditText\u306b\u5165\u529b\u3055\u308c\u305f\u6587\u5b57\u5217\u3092 DB\u767b\u9332\u3057\u3001\u30e1\u30e2\u4e00\u89a7\u306e\u8868\u793a\u3092\u66f4\u65b0\u3059\u308b\u3002\r\n public void OnPushAddButton(View v) {\r\n \/\/ EditText\u306b\u5165\u529b\u3055\u308c\u305f\u6587\u5b57\u5217\u3092\u53d6\u5f97\u3059\u308b\u3002\r\n EditText et = findViewById(R.id.et_text);\r\n String txt = et.getText().toString();\r\n et.setText(""); \/\/ \u5165\u529b\u6b04\u3092\u30af\u30ea\u30a2\r\n System.out.println("et_text : " + txt);\r\n \/\/ DB\u66f4\u65b0\u3092\u975eUI\u30b9\u30ec\u30c3\u30c9\u3067\u5b9f\u884c\u3059\u308b\u3002\r\n \/\/ \u203b\u3053\u3053\u3067\u306f Runnable\u3092\u7121\u540d\u30af\u30e9\u30b9\u3067\u4f7f\u3046\u3002\r\n new Thread(new Runnable() {\r\n @Override\r\n public void run() {\r\n System.out.println("BEGIN: OnPushAddButton Thread");\r\n AppDatabase db = getDb(getApplicationContext());\r\n MemoDao dao = db.memoDao(); \/\/ DAO\u3092\u751f\u6210\r\n Memo memo = new Memo(); \/\/ DB\u306b\u66f8\u304d\u8fbc\u3080\u30c7\u30fc\u30bf\u3092\u4f5c\u6210\r\n memo.setMemoContent(txt); \/\/ :\r\n dao.insert(memo); \/\/ DB\u306b\u66f8\u304d\u8fbc\u307f\u3092\u5b9f\u884c\r\n System.out.println("END: OnPushAddButton Thread");\r\n UpdateText(); \/\/ UI\u30b9\u30ec\u30c3\u30c9\u3067\u8868\u793a\u3092\u66f4\u65b0\r\n }\r\n }).start(); \/\/ \u4e0a\u8a18\u306e\u51e6\u7406\u3092\u5225\u30b9\u30ec\u30c3\u30c9\u3067\u5b9f\u884c\u3059\u308b\u3002\r\n }\r\n\r\n \/\/ [\u5168\u6d88\u53bb]\u30dc\u30bf\u30f3\u62bc\u4e0b\u30a4\u30d9\u30f3\u30c8\u30cf\u30f3\u30c9\u30e9\r\n \/\/ DB\u306b\u767b\u9332\u3055\u308c\u3066\u3044\u308b\u5168\u30e1\u30e2\u30c7\u30fc\u30bf\u3092\u6d88\u53bb\u3059\u308b\u3002\r\n public void OnPushAllDeleteButton(View v) {\r\n \/\/ DB\u66f4\u65b0\u3092\u975eUI\u30b9\u30ec\u30c3\u30c9\u3067\u5b9f\u884c\u3059\u308b\u3002\r\n new Thread(new Runnable() {\r\n @Override\r\n public void run() {\r\n System.out.println("BEGIN: OnPushAllDeleteButton Thread");\r\n AppDatabase db = getDb(getApplicationContext());\r\n MemoDao dao = db.memoDao(); \/\/ DAO\u3092\u751f\u6210\r\n dao.deleteAll(); \/\/ \u5168\u30ec\u30b3\u30fc\u30c9\u3092\u524a\u9664\r\n System.out.println("END: OnPushAllDeleteButton Thread");\r\n UpdateText(); \/\/ UI\u30b9\u30ec\u30c3\u30c9\u3067\u8868\u793a\u3092\u66f4\u65b0\r\n }\r\n }).start(); \/\/ \u4e0a\u8a18\u306e\u51e6\u7406\u3092\u5225\u30b9\u30ec\u30c3\u30c9\u3067\u5b9f\u884c\u3059\u308b\u3002\r\n }\r\n\r\n \/\/ [DB\u524a\u9664]\u30dc\u30bf\u30f3\u62bc\u4e0b\u30a4\u30d9\u30f3\u30c8\u30cf\u30f3\u30c9\u30e9\r\n \/\/ DB\u81ea\u4f53\u3092\u524a\u9664\u3059\u308b\u3002\r\n public void OnPushRemoveDBButton(View v) {\r\n System.out.println("BEGIN: OnPushRemoveDBButton Thread");\r\n Context context = getApplicationContext();\r\n context.deleteDatabase(dbName);\r\n dbInst = null;\r\n System.out.println("END: OnPushRemoveDBButton Thread");\r\n UpdateText(); \/\/ UI\u30b9\u30ec\u30c3\u30c9\u3067\u8868\u793a\u3092\u66f4\u65b0\r\n }\r\n}\r\n<\/pre>\n
\n","protected":false},"excerpt":{"rendered":"