Image.IO cant read input file - Java

Question

Hey i am currently trying to read the byte contents of an image into a byte array in java but cant seem to open the image from file. The console is throwing this exception:

 Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException

This here is the line in question:

BufferedImage im =
   ImageIO.read(
      new File(
         getClass().getResource( "/Images/default_pic.png" ).toURI()));

My packages look like this:

-UI
  -Class //code getting image here
-UI.Images
  -default_pic.png

The easiest way to debug a name resolution problem is to set a breakpoint on your `ImageIO.read()` and try a lot of different paths until `getResource()` or `getResourceAsStream()` returns something non-null. You can just change the code while the debugger is waiting, then select the `getClass().getResource()` method call and right-click "Inspect" to see the value. In general, Java name resolution is unpredictable and unreliable--there are no actual rules to it--so you just have to explore possibilities by trial-and-error until you hit the spot. — Byron Hawkins, Feb 23 '13 at 08:22

score 2 · Answer 1 · answered Feb 22 '13 at 10:52

2

The directory UI is missing in your path, I suggest:

BufferedImage im =
   ImageIO.read(
      getClass().getClassLoader().getResourceAsStream(
         "/UI/Images/default_pic.png" ));

answered Feb 22 '13 at 10:52

Aerospace

1,270
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thanks for the reply, after trying yours i also got an java.lang.IllegalArgumentException: input == null! exception – user1851487 Feb 22 '13 at 11:37

score 1 · Answer 2 · answered Feb 22 '13 at 10:48

1

You can try this:

BufferedImage im = ImageIO.read(getClass().getClassLoader().getResourceAsStream("/Images/default_pic.png"))

answered Feb 22 '13 at 10:48

vikingsteve

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thank you for the reply. After trying your code i got a "java.lang.IllegalArgumentException: input == null!" exception – user1851487 Feb 22 '13 at 10:52
Where is your image located? src/main/resources/Images would be correct, I believe. Also check your image is .png, not .PNG... – vikingsteve Feb 22 '13 at 10:53
the image is located in src/UI/Images – user1851487 Feb 22 '13 at 11:04
Ok, well see Aerospace's answer. I'll upvote it, can u try it? – vikingsteve Feb 22 '13 at 11:15
Did you try this without the leading "/", like "Images/default_pic.png"? – Byron Hawkins Feb 23 '13 at 07:28

score 0 · Answer 3 · answered Feb 22 '13 at 10:47

0

Check if the file uses CMYK coloring (Don't know if this only applies to jpegs). If that's the case then ImageIO can't read it without an extension.

Check http://www.randelshofer.ch/blog/2011/08/reading-cmyk-jpeg-images-with-java-imageio/

answered Feb 22 '13 at 10:47

Marcus

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Image.IO cant read input file - Java

3 Answers3