SQLiteDatabase'没有实现接口'

Question

Getting this error when I use SQLiteDatabase as a Closeable

I've got a sample project to recreate it:

https://github.com/blundell/SQLDatabaseError

With a class that extends SQLiteOpenHelper :

public class DatabaseHelper extends SQLiteOpenHelper {

....

public void openAndCloseDatabase() {
    SQLiteDatabase database = getWritableDatabase();

    close(database);
}

private void close(Closeable database) {
    try {
        if (database != null) {
            database.close();
        }
    } catch (Exception e) {
        Log.e("Error", "Oh no!", e);
    }
}

}

Stack trace:

12-14 12:23:43.719: E/AndroidRuntime(5179): FATAL EXCEPTION: main
12-14 12:23:43.719: E/AndroidRuntime(5179): java.lang.IncompatibleClassChangeError: interface not implemented
12-14 12:23:43.719: E/AndroidRuntime(5179):   at com.blundell.sqldatabasecursorerror.DatabaseHelper.close(DatabaseHelper.java:35)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at com.blundell.sqldatabasecursorerror.DatabaseHelper.openAndCloseDatabase(DatabaseHelper.java:29)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at com.blundell.sqldatabasecursorerror.MainActivity.onCreate(MainActivity.java:13)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1623)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1675)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at android.app.ActivityThread.access$1500(ActivityThread.java:121)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:943)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at android.os.Handler.dispatchMessage(Handler.java:99)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at android.os.Looper.loop(Looper.java:130)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at android.app.ActivityThread.main(ActivityThread.java:3701)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at java.lang.reflect.Method.invokeNative(Native Method)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at java.lang.reflect.Method.invoke(Method.java:507)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:624)
12-14 12:23:43.719: E/AndroidRuntime(5179):     at dalvik.system.NativeStart.main(Native Method)

API:

http://developer.android.com/reference/android/database/sqlite/SQLiteDatabase.html

http://developer.android.com/reference/android/database/sqlite/SQLiteClosable.html

http://developer.android.com/reference/java/io/Closeable.html

This should work shouldn't it?

 public final class SQLiteDatabase extends SQLiteClosable
 >>
 public abstract class SQLiteClosable extends Object implements Closeable
 >>
 public interface Closeable

Doesn't work:

• Xperia Play Android 2.3.4
• Motorola Xoom Android 4.0.4

Does work:

• Samsung Galaxy Nexus Android 4.2

Answer 1

Okay, found the problem in the Change Notes for 4.1 (API Level 16) :

android.database.sqlite.SQLiteClosable implements java.io.Closeable only from API Level 16. Before that, they were unrelated (even though both interfaces existed since the beginning).

So you should use SQLiteClosable directly if you want your code to be backwards compatible.

It is also probably worthwhile to install the SDK for the lowest version you want to support and try to build with it, then this would have been detected by the compiler.