Question

因此,我试图从FTP网站下载一个图像文件,从中获取一些元数据,然后将双元数据带回一个使用“游戏”的网页! 框架。这里是一部基本法典,在控制人的行动中使用(消除了所有对简便的错误检查):

FTPClient ftp = new FTPClient();
ftp.connect(site.host, site.port);
ftp.login(site.username, site.password);
InputStream is = ftp.retrieveFileStream("somefile.png");
Response.current().contentType = "image/png";
renderBinary(is);

我知道,投入流的真正类型是SocketInputStream,是否有特别需要做才能使用?

我也试图这样做:

BufferedImage bimg = ImageIO.read(is);

但是,双星显示为无效,因此我相信,投入流的数据并不有效。

Does anyone have any experience doing this and can point me in the right direction?

Answer 1

您可能需要将<代码>SocketInputStream改为Image InputStream。这里有关于<代码>ImageIO.read()的javadoc,它解释了为什么你没有:

Returns a BufferedImage as the result of decoding a supplied InputStream with an ImageReader chosen automatically from among those currently registered. The InputStream is wrapped in an ImageInputStream. If no registered ImageReader claims to be able to read the resulting stream, null is returned.

The current cache settings from getUseCacheand getCacheDirectory will be used to control caching in the ImageInputStream that is created.

This method does not attempt to locate ImageReaders that can read directly from an InputStream; that may be accomplished using IIORegistry and ImageReaderSpi.

This method does not close the provided InputStream after the read operation has completed; it is the responsibility of the caller to close the stream, if desired.

因此,我假定<代码>ImageReader无法读到您的行文,因此,你从电话中拿不到。

<>>>>>

可能要:

BufferedImage bimg = ImageIO.read(ImageIO.createImageInputStream(yourSocketInputStream));

你们是否做了这项工作?

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