如何从 ImageIO 中排除特定的 TIFF 阅读器?

一个完全不同的选择，是尝试使用所有已注册的 TIFF 插件读取数据，并使用第一个成功的插件.这比前面的代码更明确，但需要重写图像读取代码:byte[] 数据；BufferedImage 图像；尝试 (ImageInputStream inputStream = ImageIO.createImageInputStream(new ByteArrayInputStream(data))) {迭代器读者 = ImageIO.getImageReaders(inputStream);//尝试读取数据，使用每个读取器直到我们成功(或者没有更多的读取器)而 (readers.hasNext()) {ImageReader reader = reader.next();尝试 {reader.setInput(inputStream);图像 = reader.read(0);休息;//图像现在已正确解码}捕获(异常 e){//TODO: 记录异常?e.printStackTrace();//读取失败，尝试下一个ReaderinputStream.seek(0);}最后 {阅读器处理()；}}}您当然可以结合上述选项，以实现两全其美(即稳定的顺序和在一位读者失败时的回退).Stack:Java - 1.8.0_91Scala - 2.11.8Library - it.geosolutions.imageio-ext imageio-ext-tiff 1.1.15We are reading lots of old TIF images and for some reason read is highly inconsistent - for some reasons on a different run reading the same image can succeed or fail with exception - javax.imageio.IIOException: Invalid component ID 3 in SOSat com.sun.imageio.plugins.jpeg.JPEGImageReader.readImage(Native Method)at com.sun.imageio.plugins.jpeg.JPEGImageReader.readInternal(JPEGImageReader.java:1236)at com.sun.imageio.plugins.jpeg.JPEGImageReader.read(JPEGImageReader.java:1039)at com.sun.media.imageioimpl.plugins.tiff.TIFFOldJPEGDecompressor.decodeRaw(TIFFOldJPEGDecompressor.java:654)at com.sun.media.imageio.plugins.tiff.TIFFDecompressor.decode(TIFFDecompressor.java:2527)at com.sun.media.imageioimpl.plugins.tiff.TIFFImageReader.decodeTile(TIFFImageReader.java:1137)at com.sun.media.imageioimpl.plugins.tiff.TIFFImageReader.read(TIFFImageReader.java:1417)The code is something like this:import java.io.{ByteArrayInputStream, ByteArrayOutputStream}import javax.imageio.ImageIOdef convertToPng(data: Array[Byte]): Array[Byte] = { val inputStream = new ByteArrayInputStream(data) val image = ImageIO.read(inputStream) val outputStream = new ByteArrayOutputStream(inputStream.available()) ImageIO.write(image, "png", outputStream) outputStream.toByteArray}The problem is ImageIO initializes 2 TIFF readers at the same time com.sun.media.imageioimpl.plugins.tiff.TIFFImageReader & it.geosolutions.imageioimpl.plugins.tiff.TIFFImageReaderOR it.geosolutions.imageioimpl.plugins.tiff.TIFFImageReader com.sun.media.imageioimpl.plugins.tiff.TIFFImageReaderThe first one fails, the second one works.How to exclude com.sun.media.imageioimpl.plugins.tiff.TIFFImageReader from ImageIO configuration? 解决方案 The issue here is that ImageIO uses a service provider interface (SPI) lookup to register plugins at runtime, and in your setup, multiple plugins that can read TIFF is found. By default, the plugins does not have any specific order, which is why you sometimes get the com.sun (JAI) TIFF plugin first and sometimes the it.geosolutions (Geosolutions) TIFF plugin first. ImageIO.read(...) will only try this first plugin and give up if it fails.If you can, the easiest solution is just to remove one of the plugins from class path. But I assume you already thought of that. There are still multiple other ways to solve this (I give code examples in Java, as that's what I'm most familiar with, I'm sure you can write it more elegant in Scala ;-)).The one that requires the least changes to your code, is to unregister the JAI provider at runtime, somewhere in your "bootstrap" code (exactly where this is, depends on the application, could be a static initializer block or a web context listener or similar). The IIORegistry has a deregisterServiceProvider method for this purpose, removing the provider from the registry, and making it unavailable for ImageIO.Another option is to define an explicit order for the providers. This can be useful if you need to to have multiple providers for a single format for some reason (third-party requirements/inter-plugin dependencies etc). The IIORegistry has a setOrdering method for this purpose, that allows setting pairwise ordering of two service providers, making ImageIO always prefer one before the other.The below code shows both of the above options:// Get the global registryIIORegistry registry = IIORegistry.getDefaultInstance();// Lookup the known TIFF providersImageReaderSpi jaiProvider = lookupProviderByName(registry, "com.sun.media.imageioimpl.plugins.tiff.TIFFImageReaderSpi");ImageReaderSpi geoProvider = lookupProviderByName(registry, "it.geosolutions.imageioimpl.plugins.tiff.TIFFImageReaderSpi");if (jaiProvider != null && geoProvider != null) { // If both are found, EITHER // order the it.geosolutions provider BEFORE the com.sun (JAI) provider registry.setOrdering(ImageReaderSpi.class, geoProvider, jaiProvider); // OR // un-register the JAI provider registry.deregisterServiceProvider(jaiProvider);}// New and improved (shorter) version. :-)private static <T> T lookupProviderByName(final ServiceRegistry registry, final String providerClassName) { try { return (T) registry.getServiceProviderByClass(Class.forName(providerClassName)); } catch (ClassNotFoundException ignore) { return null; }}The above code will make sure the Geosolutions TIFF plugin will always be used by ImageIO.read(...), and your existing code should just work (but now be stable).A completely different option, is to try reading the data using all registered TIFF plugins, and use the first one that succeeds. This is more explicit than the previous code, but requires rewriting the image reading code:byte[] data;BufferedImage image;try (ImageInputStream inputStream = ImageIO.createImageInputStream(new ByteArrayInputStream(data))) { Iterator<ImageReader> readers = ImageIO.getImageReaders(inputStream); // Try reading the data, using each reader until we succeed (or have no more readers) while (readers.hasNext()) { ImageReader reader = readers.next(); try { reader.setInput(inputStream); image = reader.read(0); break; // Image is now correctly decoded } catch (Exception e) { // TODO: Log exception? e.printStackTrace(); // Reading failed, try the next Reader inputStream.seek(0); } finally { reader.dispose(); } }}You can of course combine the options above, to have the best of both worlds (ie. stable order and fallback if one reader fails). 这篇关于如何从 ImageIO 中排除特定的 TIFF 阅读器?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！ 上岸，阿里云！