How to extract images from Thumbs.db in Java?

Question

HI I read about the POI project and tried to extract images from thumbs.db, but I get an exception in the code .. Code os

InputStream stream = new FileInputStream("C:\\Thumbs.db");
POIFSFileSystem fs = new POIFSFileSystem(stream);
DirectoryEntry root = fs.getRoot();
Entry entry = root.getEntry("2");
DocumentInputStream is = fs.createDocumentInputStream(entry.getName());
JPEGImageDecoder decoder = JPEGCodec.createJPEGDecoder(is);
JPEGDecodeParam param = JPEGCodec.getDefaultJPEGEncodeParam(4,    JPEGDecodeParam.COLOR_ID_RGBA);
decoder.setJPEGDecodeParam(param);
BufferedImage originalBufferedImage = decoder.decodeAsBufferedImage();

Getting an exception like "com.sun.image.codec.jpeg.ImageFormatException: not a jpeg file: starts at 0x0c 0x00"

What is the problem with the above case? Can you suggest another way to do the above tasks?

Answer 1

Before you start extracting images, you need to read the Thumbs.db file header. Try with the changes that I added below, it should delete the ImageFormatExceptionone you receive.

InputStream stream = new FileInputStream("C:\\Thumbs.db");
POIFSFileSystem fs = new POIFSFileSystem(stream);
DirectoryEntry root = fs.getRoot();
Entry entry = root.getEntry("2");
DocumentInputStream is = fs.createDocumentInputStream(entry.getName());

//Added to read the header lines and fix the ImageFormatException
int header_len = is.read();
for (int i = 1; i < header_len; i++) {
        is.read();
}

JPEGImageDecoder decoder = JPEGCodec.createJPEGDecoder(is);
JPEGDecodeParam param = JPEGCodec.getDefaultJPEGEncodeParam(4,JPEGDecodeParam.COLOR_ID_RGBA);
decoder.setJPEGDecodeParam(param);
BufferedImage originalBufferedImage = decoder.decodeAsBufferedImage();

I hope this helps!