copy existing database on SD card

when i am running android application it store database directly in internal memory of emulator but application(.apk file) store in external storage.i am using 230 mb database ..i done following setting also

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
 <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
 <manifest android:installLocation="preferExternal" >
 

in androidmainfest.xml file

public void copyDatabase() throws IOException 
     {
         if(!Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()))
         {
             Toast.makeText(mycontext,"External Sd card not mounted", Toast.LENGTH_LONG).show();
         }
         try
         {
             InputStream in=mycontext.getAssets().open("Demo.db");
             File outFile =new File(Environment.getExternalStorageDirectory()+File.separator+ "Demo.db);
             outFile.createNewFile();
             OutputStream out= new FileOutputStream(outFile);
             byte[] buf = new byte[1024];
             int len;
             while((len = in.read(buf))> 0)
             {
                 out.write(buf,0,len);
             }
             out.close();
             in.close();
             Log.i("copyDatabase","Database Has been transferred");
 
         }
         catch(IOException e)
         {
             Log.i("CopyDatabase","could not copy database");
         }
 
     }
     public  boolean checkDatabase() 
     {   
         SQLiteDatabase checkdb=null;
     try
     {
         String myPath="/sdcard/demo.db";
         checkdb=SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
 
         Log.i("checkDatabase database path",checkdb.getPath());
     }
     catch(SQLiteException e)
     {
         Log.e("Database doesn`t exist",e.toString());
     }
     if(checkdb!=null)
     {
         checkdb.close();
     }
     return checkdb != null ? true : false;
 
 
     }
     public void openDatabase() throws SQLException
     {
         String myPath="/sdcard/demo.db"
         myDatabase=SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);
     }
 

I am getting this error INSTALL_FAILED_DEXOPT

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