For some reason, whenever I try to copy over a database from my assets folder to the database directy on an emulator or some phones (works on most phones) I get a crash. I have narrowed it down to this piece of code.
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
Heres the whole code for the helper class
public class NewDbHelper extends SQLiteOpenHelper {
//The Android's default system path of your application database.
private static String DB_PATH = "/data/data/com.bv.studyguide/databases/";
private static String DB_NAME = "studyguide.db";
private SQLiteDatabase myDataBase;
private final Context myContext;
private static int DB_VERSION = 2;
private SQLiteDatabase db;
private Cursor cursor;
/**
* Constructor
* Takes and keeps a reference of the passed context in order to access to the application assets and resources.
* @param context
*/
public NewDbHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);
this.myContext = context;
}
/**
* Creates a empty database on the system and rewrites it with your own database.
* */
public void createDataBase() throws IOException{
boolean dbExist = checkDataBase();
if (dbExist) {
Log.v("DB Exists", "db exists");
// By calling this method here onUpgrade will be called on a
// writeable database, but only if the version number has been
// bumped
this.getWritableDatabase();
}
dbExist = checkDataBase();
if (!dbExist) {
// By calling this method and empty database will be created into
// the default system path of your application so we are gonna be
// able to overwrite that database with our database.
this.getReadableDatabase();
try {
copyDataBase();
} catch (IOException e) {
throw new Error("Error copying database");
}
}
}
/**
* Check if the database already exist to avoid re-copying the file each time you open the application.
* @return true if it exists, false if it doesn't
*/
private boolean checkDataBase(){
SQLiteDatabase checkDB = null;
try{
String myPath = DB_PATH + DB_NAME;
checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}catch(SQLiteException e){
//database does't exist yet.
}
if(checkDB != null){
checkDB.close();
}
return checkDB != null ? true : false;
}
/**
* Copies your database from your local assets-folder to the just created empty database in the
* system folder, from where it can be accessed and handled.
* This is done by transfering bytestream.
* */
private void copyDataBase() throws IOException{
//Open your local db as the input stream
InputStream myInput = myContext.getAssets().open(DB_NAME);
// Path to the just created empty db
String outFileName = DB_PATH + DB_NAME;
//Open the empty db as the output stream
OutputStream myOutput = new FileOutputStream(outFileName);
//transfer bytes from the inputfile to the outputfile
byte[] buffer = new byte[1024];
int length;
while ((length = myInput.read(buffer))>0){
myOutput.write(buffer, 0, length);
}
//Close the streams
myOutput.flush();
myOutput.close();
myInput.close();
}
public void openDataBase() throws SQLException{
//Open the database
String myPath = DB_PATH + DB_NAME;
myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
}
@Override
public synchronized void close() {
if(myDataBase != null)
myDataBase.close();
super.close();
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE android_metadata (locale TEXT)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
if (newVersion > oldVersion)
Log.v("Database Upgrade","Database version higher than old.");
myContext.deleteDatabase(DB_NAME);
}
Code runs fine until it gets to the actual while loop. Doesnt enter the loop at all, just crashes on the while line with an IO Exception. I dont know what that means, and im not very versed with InputStream and OutputStream so im lost as to what the problem could be. Works fine on my Droid X and Droid 2, but not on Droid 1 or LG670. Anyone have any ideas?
Heres the stack trace:
java.lang.Error: Error copying database
at com.bv.studyguide.NewDbHelper.createDataBase(NewDbHelper.java:63)
at com.bv.studyguide.ArmyStudyGuide.onCreate(ArmyStudyGuide.java:39)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
at android.app.ActivityThread.access$2300(ActivityThread.java:125)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4627)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:893)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:651)
at dalvik.system.NativeStart.main(Native Method)
UPDATE:
Im also running into a problem with another app with the same code (practically). Except its not giving an exception when copying the database. It copies the whole database, but then decides not to put anything in the database. So it reads 3072 bytes, but the only table that is in it is the android_metadata table. Im really getting confused. Is this byte array causing the problem?
I figuerd out the problem. Before Gingerbread Android wouldnt allow you to access files larger than 1GB from the assets folder. So, I just fragmented the files, and made a method that looped through them and put htem back together at run time.