【Kotlin】基于Room对SQLite操作

gradle中添加引用 一下引用有重复，可以删除部分，我这个在项目中，懒得删除了

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def room_version = "2.3.0"     implementation 'androidx.room:room-common:2.3.0'     implementation 'androidx.room:room-runtime:2.3.0'     annotationProcessor 'androidx.room:room-compiler:2.3.0' //其中latest.release指代最新Bugly SDK版本号，也可以指定明确的版本号，例如4.0.3 //    implementation 'com.tencent.rqd:nativecrashreport:latest.release' //其中latest.release指代最新Bugly NDK版本号，也可以指定明确的版本号，例如3.9.2         implementation "androidx.room:room-runtime:$room_version"     annotationProcessor "androidx.room:room-compiler:$room_version"       // To use Kotlin annotation processing tool (kapt)     kapt "androidx.room:room-compiler:$room_version"

　　定义实体,也就是表

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@Entity(tableName = "t_avail_data") data class AvailDataEntity(     @PrimaryKey(autoGenerate = true)  val id: Int,     @ColumnInfo(name="created_at") val created_at: String )

　　定义操作接口

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@Dao open interface BaseKotlinDao<T> {     @Insert(onConflict = OnConflictStrategy.REPLACE)     fun insertAll(vararg operations: T);       @Insert(onConflict = OnConflictStrategy.REPLACE)     fun insert(operation: T);       @Delete     fun delete(operation: T);       @Update     fun update(operation: T);       open fun getAll(): List<T>;   }

　　定义具体业务接口

　　

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@Dao interface AvailDataDao: BaseKotlinDao<AvailDataEntity> {     /**      * 获取所有      */     @Query("SELECT * from t_avail_data")     override fun getAll(): List<AvailDataEntity> ;       /**      * 根据Rrid 获取      */     @Query("SELECT * from t_avail_data WHERE id=(:id) Limit 1")     fun getById(id:Int): AvaidDataEntity;       /**      * 清空表      */     @Query("delete from t_avail_data")     fun clean(); }

　　定义DataBase

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@Database(entities = {AvalidDataEntity.class}, version = 1, exportSchema = false) public abstract class AppDataBase extends RoomDatabase {     public  AvalidDataDao avalidDataDao(); }

　　创建DbUtil

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public class DbUtil {       private static AppDataBase db = null;     private static Context context = ContextUtils.getApplicationContext();         public static AppDataBase getDb() {         if (db == null) {             db = Room.databaseBuilder(context,                     AppDataBase.class, "icebox-system-06").allowMainThreadQueries().fallbackToDestructiveMigration().build();         }         return db;     }       public static void setContext(Context context) {         DbUtil.context = context;     }         public static void setPopupWindowTouchModal(PopupWindow popupWindow, boolean touchModal) {         if (null == popupWindow) {             return;         }         Method method;         try {             method = PopupWindow.class.getDeclaredMethod("setTouchModal", boolean.class);             method.setAccessible(true);             method.invoke(popupWindow, touchModal);         } catch (Exception e) {             e.printStackTrace();         }     } }

　　上下文工具ContextUtils

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public class ContextUtils {     private static Context applicationContext = null;       public static Context getApplicationContext() {         if (null != applicationContext) {             return applicationContext;         }           final Object activityThread = getActivityThread();         if (null != activityThread) {             try {                 final Method getApplication = activityThread.getClass().getDeclaredMethod("getApplication");                 getApplication.setAccessible(true);                 applicationContext = (Context) getApplication.invoke(activityThread);             } catch (Exception e) {                 e.printStackTrace();             }         }           return applicationContext;     }       private static Object getActivityThread() {         try {             final Class<?> clz = Class.forName("android.app.ActivityThread");             final Method method = clz.getDeclaredMethod("currentActivityThread");             method.setAccessible(true);             final Object activityThread = method.invoke(null);             return activityThread;         } catch (Exception e) {             e.printStackTrace();         }         return null;     } }

　　

使用的例子后面补充