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by HeHe » Wed, 21 Apr 2010 07:02:21 GMT
as title. thank you. --
1. Android Bluetooth Stack Limitations
Hi I've been reading the several posts about the limitations of Bluetooth in Android handsets. My system requires establishing connections with all the devices which it encounters in the environment (with the same UUID) and also accept connections from other. In this scenario, each Android handset should provide client and server features simultaneously. The first limitation seems to be regarding the need to pair devices in order to enable communication between them. Is there any way of by- passing this step grammatically? (is it necessary to go to the Bluezd driver for that?). I was diving in the source code and I couldn't find the right way of doing it. Secondly, it looks like it is not possible to listen for incoming connections when there are other ongoing connections or, on the other hand, it doesn't allow establishing new connections if there is also another thread listening for incoming connections. In some posts which can be found in stackoverflow and other google groups (e.g. developers) looks like it is not possible to have a listening socket and a connection socket at the same time. In my case, it throws exceptions such as: java.io.IOException: socket closed (in the client side) and java.io.IOException: Software caused connection abort (in the server side) java.io.IOException: Operation Canceled java.io.IOException: Connection timed out Does anyone know why google disables all those features and how they can be by-passed? Does it require modifying the Bluetooth driver or can be done at a higher level? Many thanks, F --
2. IllegalStateException: database not open
I had an existing working application which was creating a database using SQLite helper/code. In another application, which I am developing I copied app1's DBHelper code and honestly forgetting to rename the database name in the DBHelper, which I copied from app1 code. Now I keep getting following error for both app1 (from which I copied DBHelper code) and app2 as well. Caused by: java.lang.IllegalStateException: database not open. Seems like something is badly screwed up. Any idea? Also when I tried to view database from adb shell I get Permission Defined error. 02-15 21:31:25.798: WARN/dalvikvm(10965): threadid=1: thread exiting with uncaught exception (group=0x400259f8) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): FATAL EXCEPTION: main 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): java.lang.RuntimeException: Unable to start activity ComponentInfo AddressActivity}: java.lang.IllegalStateException: database not open 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java: 2787) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java: 2803) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at android.app.ActivityThread.access$2300(ActivityThread.java:135) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2136) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at android.os.Handler.dispatchMessage(Handler.java:99) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at android.os.Looper.loop(Looper.java:144) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at android.app.ActivityThread.main(ActivityThread.java:4937) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at java.lang.reflect.Method.invokeNative(Native Method) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at java.lang.reflect.Method.invoke(Method.java:521) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at com.android.internal.os.ZygoteInit $MethodAndArgsCaller.run(ZygoteInit.java:868) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at dalvik.system.NativeStart.main(Native Method) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): Caused by: java.lang.IllegalStateException: database not open 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at android.database.sqlite.SQLiteDatabase.endTransaction(SQLiteDatabase.java: 611) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java: 113) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at DataHelper.<init>(DataHelper.java:37) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at AddressActivity.onCreate(AddressActivity.java:15) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java: 1069) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java: 2751) 02-15 21:31:25.808: ERROR/AndroidRuntime(10965): ... 11 more --