Is JAI closing file handles too early?

问题

I'm using JAI to read Tiff files in java. with this code:

RenderedOp renderer = JAI.create("fileload", tifFilename);
return renderer.getAsBufferedImage();

Worked fine on one box with java 7, but on others with java 8, get this:

Caused by: com.sun.media.jai.codecimpl.util.ImagingException
    at com.sun.media.jai.codecimpl.ImagingListenerProxy.errorOccurred(ImagingListenerProxy.java:63)
    at com.sun.media.jai.codecimpl.TIFFImage.getTile(TIFFImage.java:1087)
    at javax.media.jai.RenderedImageAdapter.getTile(RenderedImageAdapter.java:148)
    at javax.media.jai.NullOpImage.computeTile(NullOpImage.java:162)
    at com.sun.media.jai.util.SunTileScheduler.scheduleTile(SunTileScheduler.java:904)
    at javax.media.jai.OpImage.getTile(OpImage.java:1129)
    at javax.media.jai.PlanarImage.copyData(PlanarImage.java:2343)
    at javax.media.jai.RenderedImageAdapter.copyData(RenderedImageAdapter.java:163)
    at javax.media.jai.RenderedOp.copyData(RenderedOp.java:2299)
    at javax.media.jai.PlanarImage.getAsBufferedImage(PlanarImage.java:2525)
    at javax.media.jai.PlanarImage.getAsBufferedImage(PlanarImage.java:2546)
    at  ...
Caused by: com.sun.media.jai.codecimpl.util.ImagingException: IOException occured while reading TIFF image data.
    ... 17 more
Caused by: java.io.IOException: Stream Closed
    at java.io.RandomAccessFile.seek0(Native Method)
    at java.io.RandomAccessFile.seek(RandomAccessFile.java:557)
    at com.sun.media.jai.codec.FileSeekableStream.read(FileSeekableStream.java:168)
    at com.sun.media.jai.codec.SeekableStream.readFully(SeekableStream.java:318)
    at com.sun.media.jai.codecimpl.TIFFImage.getTile(TIFFImage.java:1081)
    ... 16 more

回答1:

My theory is that garbage collection was kicking in and finalizing something it shouldn't. very weird. replacing it with this:

try (SeekableStream seekableStream = new FileSeekableStream(filename)){
  TIFFDecodeParam param = null;
  ImageDecoder dec = ImageCodec.createImageDecoder("tiff", seekableStream, param);
  // convert to buffered image if desired
  return new RenderedImageAdapter(dec.decodeAsRenderedImage()).getAsBufferedImage(); // convert to buffered image
}

and the problem seems to go away. My guess is because the FileSeekableStream s is not prematurely collected since a handle to it remains in the local variable scope. There are probably other JAI ways to do this as well, just make sure to keep your own handle on the inputstream [?]

related (helped me discover this work around: RenderedImage to BufferedImage for multipage-tiff reading)

also JAI create seems to leave file descriptors open

not sure if also applies to other image formats

来源：https://stackoverflow.com/questions/38444752/is-jai-closing-file-handles-too-early

标签

java

garbage-collection

jai