Question

I am developing an Android that uses a database. I want to copy the database to the SD card when use true machine run. But it doesn’t always succeed. My program doesn’t say why, only that it can’t copy the database. I store the database in res\raw\mobilephone1.db; it’s 10 MB. I set the permissions to allow writing data to the SD card.

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
  <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS"></uses-permission>

Is this right?

private final String DATABASE_PATH = android.os.Environment  
                .getExternalStorageDirectory().getAbsolutePath()  
                + "/mobilephone";  
    private final String DATABASE_FILENAME = "mobilephone.db"; 


private SQLiteDatabase openDatabase()  
    {  
        try  
        {  
            // obtain absolute path of mobilephone.db  
            String databaseFilename = DATABASE_PATH + "/" + DATABASE_FILENAME;  
            File dir = new File(DATABASE_PATH);          
            // if/sdcard/mobilephone exist，crtate this list 
            if (!dir.exists()) {  
                dir.mkdir();  
                }
            // if  mobilephone.db file did not exist in/sdcard/mobilephone then copy this filt to SD card list（/sdcard/mobilephone） from res\raw
            if (!(new File(databaseFilename)).exists())  
            {  

                // obtain the InputStream object that encapsulate mobilephone.db
                InputStream is = getResources().openRawResource(R.raw.mobilephone1);  
                FileOutputStream fos = new FileOutputStream(databaseFilename);  

                int count = 0;
                while (count == 0) {
                 count = is.available();
                }
                byte[] buffer = new byte[count];

                int readCount = 0; // the number of bytes that has successfully readen
                while (readCount < count) {
                 readCount += is.read(buffer, readCount, count - readCount);
                }

                fos.write(buffer, 0, count); 
                fos.close();  
                is.close();  
            }  
            // go to mobilephone.db in /sdcard/mobilephone  
            SQLiteDatabase database = SQLiteDatabase.openOrCreateDatabase(  
                   databaseFilename, null);  
            return database;  
        }  
        catch (Exception e)  
        {  
        }  
        return null;  
    }  

Answer 1

Try this one out ::

File sd = Environment.getExternalStorageDirectory();

File src = new File("YOUR_SOURCE_PATH");

File dest = new File(sd +  "/" +DATABASE_NAME);

      try 
      {
          if (Environment.getExternalStorageDirectory().canWrite()) 
          {                 
              if (srcdb.exists()) 
              {
                  FileChannel src = new FileInputStream(srcdb).getChannel();
                  FileChannel dst = new FileOutputStream(destdb).getChannel();
                  dst.transferFrom(src, 0, src.size());
                  src.close();
                  dst.close();  
                  flag=0; 

              }
              else
              {
                  Toast.makeText(getApplicationContext(), "ERROR: File not found in Database " , Toast.LENGTH_LONG).show();                    
              }
          }
          else
          {
              Toast.makeText(getApplicationContext(), "ERROR: Cannot write to file" , Toast.LENGTH_LONG).show();
          }
      }
      catch (Exception e) 
      {
          Log.e("Movedb", "Error in Copying" + e.toString());

      }

Also you need only one permission :

 <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>