sqlite - Can't open database from assets folder [Android] -

sorry such lame problem, can't solve 4 hours. i'm trying copy database /assets folder use sqliteopenhelper, when try open inputstream gives me error:

 e/trace: error opening trace file: no such file or directory (2) 

code:

public static final string database_path =  "/data/data/com.mycomp.myapp/databases/"; public static final string database_name = "database.db";   @override     protected void oncreate(bundle savedinstancestate) {            try {             copydatabase(getapplicationcontext());         } catch (ioexception e) {             e.printstacktrace();             log.d(tag, "blad" + e.tostring());         }     }      private void copydatabase(context context) throws ioexception {        string outfilename = database_path + database_name;         inputstream myinput = context.getassets().open("database.db");         outputstream myoutput = new fileoutputstream(outfilename);         byte[] buffer = new byte[1024];        int length;        while ((length = myinput.read(buffer)) > 0) {           myoutput.write(buffer, 0, length);       }         myoutput.flush();        myoutput.close();        myinput.close();     } 

can try code , please tell me result. sure check file names.

@override protected void oncreate(bundle savedinstancestate) {        //.......      databasehelper dbhelper = new databasehelper(this);     dbhelper.createdatabase();      dbhelper.opendatabase();     // stuff     cursor data =dbhelper.sample_use_of_helper();     dbhelper.close(); }   class databasehelper extends sqliteopenhelper {      private static string db_path = "/data/data/com.mycomp.myapp/databases/";     private static string db_name = "database.db";     private sqlitedatabase mydatabase;     private final context mycontext;          public databasehelper (context context) {             super(context, db_name, null, 1);             this.mycontext = context;         }          public void cratedatabase() throws ioexception {             boolean vtvarmi = isdatabaseexist();              if (!vtvarmi) {                 this.getreadabledatabase();                  try {                     copydatabase();                 } catch (ioexception e) {                     throw new error("error copying database");                 }             }         }          private void copydatabase() throws ioexception {              // open local db input stream             inputstream myinput = mycontext.getassets().open(db_name);              // path created empty db             string outfilename = db_path + db_name;              // open empty db output stream             outputstream myoutput = new fileoutputstream(outfilename);              // transfer bytes inputfile outputfile             byte[] buffer = new byte[1024];             int length;             while ((length = myinput.read(buffer)) > 0) {                 myoutput.write(buffer, 0, length);             }              // close streams             myoutput.flush();             myoutput.close();             myinput.close();         }          private boolean isdatabaseexist() {             sqlitedatabase kontrol = null;              try {                 string mypath = db_path + db_name;                 kontrol = sqlitedatabase.opendatabase(mypath, null, sqlitedatabase.open_readonly);              } catch (sqliteexception e) {                 kontrol = null;             }              if (kontrol != null) {                 kontrol.close();             }             return kontrol != null ? true : false;         }          public void opendatabase() throws sqlexception {              // open database             string mypath = db_path + db_name;             mydatabase = sqlitedatabase.opendatabase(mypath, null, sqlitedatabase.open_readwrite);          }          public cursor sample_use_of_helper() {              return mydatabase.query("table_name", null, null, null, null, null, null);         }          @override         public synchronized void close() {             if (mydatabase != null)                 mydatabase.close();             super.close();         }          @override         public void oncreate(sqlitedatabase db) {         }          @override         public void onupgrade(sqlitedatabase db, int oldversion, int newversion) {         }     }