Question

HI 我读了关于POI项目并尝试从thumbs.db中提取图像但在代码中获得异常。代码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();

获取异常为“com.sun.image.codec.jpeg.ImageFormatException：不是JPEG文件：以0x0c 0x00开头”

上述情况有什么问题？你能建议其他方法做上述任务吗？

Answer 1

在开始提取图像之前，需要先读取Thumbs.db文件的标题。尝试我在下面添加的更改，它应该删除您获得的ImageFormatException。

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();

我希望有所帮助！

如何从Java中的Thumbs.db中提取图像？

1 个答案: