Android 및 db4o.Can 에뮬레이터에서 db를 만들지 만 실제 장치에는 생성하지 마십시오.

Question

첫 번째 Android 앱을 쓰고 있습니다. 그리고 db4o를 사용하고 싶었습니다. 전에 사용하지 않았기 때문입니다. 나는 열려고/database.Everything 가상 장치에서 이걸 실행할 때 잘 작동하도록 만듭니다. 메신저 내 진짜 장치에 갈 때하지만 난 항상 예외는 아래에 서면 얻을 :

...ActivityClass{ 
private void deleteDB() { 
    DatabaseHandler db = new DatabaseHandler(); 
    db.open(getString(R.string.database)); 
    db.deleteAll(); 
    db.close(); 
} 
}.... 
The R.string.database = /data/data/de.workingtimemanager.urb/databases/WTM.db 
my package = de.workingtimemanager.urb 

public class DatabaseHandler { 
    private ObjectContainer database; 
public DatabaseHandler() {} 

public void open(String name) { 
    EmbeddedConfiguration conf = Db4oEmbedded.newConfiguration(); 
    conf.common().objectClass(User.class).cascadeOnDelete(true); 
    conf.common().objectClass(User.class).cascadeOnUpdate(true); 
    conf.common().objectClass(Project.class).cascadeOnDelete(true); 
    conf.common().objectClass(Project.class).cascadeOnUpdate(true); 
    database = Db4oEmbedded.openFile(conf, name); 
    } 
} 
11-01 13:38:36.385: ERROR/AndroidRuntime(4774): java.lang.RuntimeException: Unable to start activity ComponentInfo{de.workingtimemanager.urb/de.workingtimemanager.urb.WorkingTimeManagerActivity}: com.db4o.ext.Db4oIOException: /data/data/de.workingtimemanager.urb/databases/WTM.db (No such file or directory) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1651) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1667) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at android.app.ActivityThread.access$1500(ActivityThread.java:117) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at android.os.Handler.dispatchMessage(Handler.java:99) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at android.os.Looper.loop(Looper.java:123) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at android.app.ActivityThread.main(ActivityThread.java:3691) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at java.lang.reflect.Method.invokeNative(Native Method) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at java.lang.reflect.Method.invoke(Method.java:507) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:847) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:605) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at dalvik.system.NativeStart.main(Native Method) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774): Caused by: com.db4o.ext.Db4oIOException: /data/data/de.workingtimemanager.urb/databases/WTM.db (No such file or directory) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.io.RandomAccessFileFactory.newRandomAccessFile(RandomAccessFileFactory.java:26) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.io.FileStorage$FileBin.<init>(FileStorage.java:43) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.io.FileStorage.open(FileStorage.java:22) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.io.StorageDecorator.open(StorageDecorator.java:27) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.io.CachingStorage.open(CachingStorage.java:52) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.internal.IoAdaptedObjectContainer.openImpl(IoAdaptedObjectContainer.java:57) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.internal.ObjectContainerBase$1.run(ObjectContainerBase.java:140) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.foundation.DynamicVariable.with(DynamicVariable.java:54) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.foundation.Environments.runWith(Environments.java:28) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.internal.ObjectContainerBase.withEnvironment(ObjectContainerBase.java:161) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.internal.ObjectContainerBase.open(ObjectContainerBase.java:131) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.internal.IoAdaptedObjectContainer.<init>(IoAdaptedObjectContainer.java:35) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.internal.ObjectContainerFactory.openObjectContainer(ObjectContainerFactory.java:18) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.Db4oEmbedded.openFile(Db4oEmbedded.java:65) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at de.workingtimemanager.urb.db.DatabaseHandler.open(DatabaseHandler.java:33) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at de.workingtimemanager.urb.WorkingTimeManagerActivity.deleteDB(WorkingTimeManagerActivity.java:22) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at de.workingtimemanager.urb.WorkingTimeManagerActivity.onCreate(WorkingTimeManagerActivity.java:15) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1615) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  ... 11 more 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774): Caused by: java.io.FileNotFoundException: /data/data/de.workingtimemanager.urb/databases/WTM.db (No such file or directory) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at org.apache.harmony.luni.platform.OSFileSystem.open(Native Method) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at dalvik.system.BlockGuard$WrappedFileSystem.open(BlockGuard.java:232) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at java.io.RandomAccessFile.<init>(RandomAccessFile.java:132) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at java.io.RandomAccessFile.<init>(RandomAccessFile.java:173) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  at com.db4o.io.RandomAccessFileFactory.newRandomAccessFile(RandomAccessFileFactory.java:19) 

11-01 13:38:36.385: ERROR/AndroidRuntime(4774):  ... 29 more 

Answer 1

당신이 작성하고 해당 위치에 파일을 쓸 수 있는지를 점검 했습니까? db4o jar 파일이 라이브러리에있는

String filePath = this.getFilesDir() + "/android.db4o"; 
    final EmbeddedConfiguration config = Db4oEmbedded.newConfiguration(); 
    config.common().add(new AndroidSupport()); 
    ObjectContainer db = Db4oEmbedded.openFile(config,filePath); 

Answer 2

확인 여부 : 일반적으로 당신은 당신이 적절한 권한이 있는지 확인하기 위해이에 대한 데이터 디렉토리를 사용합니다. 라이브러리에도 AndroidDependency이있는 경우 db4o jar 파일도 포함되어야합니다. 존재하지 않으면 ClassNotFoundError이 발생할 수 있습니다.

중위이 문제를 해결하기 위해, u는 프로젝트 라이브러리에서 AndroidDependency를 제거하거나 AndroidDependency

에 db4o jar 파일을 추가 할 수 있습니다