在遵循设置Room持久性库的教程时,当在Android设备上测试时,我遇到了这个错误。
java.lang.RuntimeException:无法找到PackageName.AppDatabase的实现。 AppDatabase_Impl不存在
我知道有类似的问题被提出过,但是这些问题是由于kotlin gradle问题而引起的。 可能的重复问题
测试类:
@RunWith(AndroidJUnit4.class)
public class LocalDatabaseTest {
private PhotoDao mPhotoDao;
private AppDatabase mDb;
@Before
public void createDb() {
Context context = InstrumentationRegistry.getTargetContext();
mDb = Room.inMemoryDatabaseBuilder(context.getApplicationContext(), AppDatabase.class).build();
mPhotoDao = mDb.photoDao();
}
@After
public void closeDb() throws IOException {
//mDb.close();
}
@Test
public void testPreConditions() {
assertNotNull(mDb);
}
道:
@Dao
public interface PhotoDao {
@Delete()
public void delete(Photo... photos);
@Update
public void update(Photo ... photos);
@Insert
public void insert(Photo ... photos);
}
数据库:
@Database(entities = {Photo.class}, version = 1)
public abstract class AppDatabase extends RoomDatabase {
public abstract PhotoDao photoDao();
}
堆栈跟踪:
java.lang.RuntimeException: cannot find implementation for *PackageName*.AppDatabase. AppDatabase_Impl does not exist
at android.arch.persistence.room.Room.getGeneratedImplementation(Room.java:90)
at android.arch.persistence.room.RoomDatabase$Builder.build(RoomDatabase.java:340)
at pics.chooz.choozpics.LocalDatabaseTest.createDb(LocalDatabaseTest.java:40)
at android.support.test.internal.runner.TestExecutor.execute(TestExecutor.java:59)
at android.support.test.runner.AndroidJUnitRunner.onStart(AndroidJUnitRunner.java:262)
at android.app.Instrumentation$InstrumentationThread.run(Instrumentation.java:1853)
Gradle:
apply plugin: "com.android.application"
apply plugin: "android-apt"
android {
compileSdkVersion 25
buildToolsVersion "25.0.2"
defaultConfig {
applicationId "*Package Name*"
minSdkVersion 16
targetSdkVersion 25
versionCode 50
versionName "1.0.32"
multiDexEnabled true
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
}
dexOptions {
javaMaxHeapSize "4g"
}
buildTypes {
release {
minifyEnabled false
proguardFiles getDefaultProguardFile("proguard-android.txt"), "proguard-rules.pro"
}
debug {
debuggable true
}
}
lintOptions {
abortOnError false
disable "ResourceType"
}
sourceCompatibility = 1.7
targetCompatibility = 1.7
compileOptions {
sourceCompatibility JavaVersion.VERSION_1_7
targetCompatibility JavaVersion.VERSION_1_7
}
packagingOptions {
exclude 'META-INF/ASL2.0'
exclude 'META-INF/LICENSE'
exclude 'META-INF/NOTICE'
}
}
dependencies {
androidTestCompile "com.android.support:support-annotations:$androidVersion"
androidTestCompile 'com.android.support.test:runner:0.5'
androidTestCompile 'com.android.support.test:rules:0.5'
compile "android.arch.persistence.room:runtime:1.0.0-alpha1"
annotationProcessor "android.arch.persistence.room:compiler:1.0.0-alpha1"
}