[Gdal-dev] Strange error during Driver.Create(String filename,...)

[Daniele Romagnoli]

Hi list,
In the context of the GDAL ImageIO integration proposal I'm actually
building the framework which will add writing capabilities to the project.

Today I'm fighting against a strange error with Driver.Create (...) method.

>From a stand-alone testCase (I'm using Junit) the following code works
successfully:
------------------------------------------------------------------------------------------------
final File outputFile = new File
("d:\\DatiPlugin\\samples\\writingAttempt.jp2");
final BufferedImage im = ImageIO.read(new
File("D:\\DatiPlugin\\bogota.tif"));
Driver driver = gdal.GetDriverByName("JP2ECW");
final int width = im.getWidth();
final int height = im.getHeight();
Dataset ds = driver.Create (outFile.getAbsolutePath(), width, height, 1,
gdalconstConstants.GDT_Byte,null);

... some code ...

ds.GetRasterBand(1).WriteRaster_Direct(0,0,width,height,width,height,
gdalconstConstants.GDT_Byte,myByteBuffer);
ds.FlushCache();
ds.delete();
------------------------------------------------------------------------------------------------

However, using the SAME code within the body of the "write" method of the
MyJP2KImageWriter class (which extends ImageWriter), it does not work.
(Such a method will be called during an ImageWrite operation performed using
JAI-ImageIO toolkit).

I noticed that the code only works if I chose a filename with a path
containing no subdirectory... As an instance, using "D:\\sample.jp2" instead
of "D:\\DatiPlugin\\samples\\sample.jp2".
(Out of curiosity, I tried using a BMP driver and the problem still exist)

After a deep debug, I finally noticed that the problem could be attributable
to the GDAL methods:

FILE *VSIFOpenL( const char * pszFilename, const char * pszAccess ) [from
cpl_vsil.cpp]

which calls

VSIVirtualHandle *VSIWin32FilesystemHandler::Open( const char *pszFilename,
const char *pszAccess ) [from cpl_vsil_win32.cpp]

containing the code

hFile = CreateFile( pszFilename, dwDesiredAccess, FILE_SHARE_READ |
FILE_SHARE_WRITE, NULL, dwCreationDisposition,  dwFlagsAndAttributes, NULL
);

which makes hFile equal to INVALID_HANDLE_VALUE (By this reason, the Open
method returns NULL).


Could someone provide me some suggestions?

Thanks a lot.

Best Regards,
Daniele
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