如何在 Java 中从 Thumbs.db 中提取图像? [英] How to extract images from Thumbs.db in Java?

问题描述

嗨我阅读了 POI 项目并尝试从 thumbs.db 中提取图像，但在代码中出现异常 .. Code os

HI I read about POI project and tried to extract images from thumbs.db but getting exception in 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();

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

Getting exception as "com.sun.image.codec.jpeg.ImageFormatException: Not a JPEG file: starts with 0x0c 0x00"

上述案例有什么问题?你能建议一些其他方法来完成上述任务吗?

What is problem with above case ? Can you suggest some other way to do above task ?

推荐答案

在开始提取图像之前，您需要阅读 Thumbs.db 文件的标题.尝试使用我在下面添加的更改，它应该删除您获得的 ImageFormatException.

You need to read the header of the Thumbs.db file before you can start extracting the images. Try with the changes I added below, it should remove the ImageFormatException you are getting.

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();

希望能帮到你！

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