[Java] PNGException

  • Java
  • Thread starter haxor489
  • Start date
  • #1
25
0

Main Question or Discussion Point

I'm getting this error

sun.awt.image.PNGImageDecoder$PNGException: crc corruption
at sun.awt.image.PNGImageDecoder.getChunk(Unknown Source)
at sun.awt.image.PNGImageDecoder.getData(Unknown Source)
at sun.awt.image.PNGFilterInputStream.read(Unknown Source)
at java.util.zip.InflaterInputStream.fill(Unknown Source)
at java.util.zip.InflaterInputStream.read(Unknown Source)
at java.io.BufferedInputStream.fill(Unknown Source)
at java.io.BufferedInputStream.read1(Unknown Source)
at java.io.BufferedInputStream.read(Unknown Source)
at sun.awt.image.PNGImageDecoder.produceImage(Unknown Source)
at sun.awt.image.InputStreamImageSource.doFetch(Unknown Source)
at sun.awt.image.ImageFetcher.fetchloop(Unknown Source)
at sun.awt.image.ImageFetcher.run(Unknown Source)



This is the segment of code causing the error.

Code:
URLConnection con = new URL("www.example.com").openConnection();
		InputStream is = con.getInputStream();
		byte bytes[] = new byte[con.getContentLength()];
		
		BufferedInputStream bis = new BufferedInputStream(is);
		bis.read(bytes);
		bis.close();
		con.getInputStream().close();
		
		Toolkit tk = getToolkit();
		
		image.setImage(tk.createImage(bytes));
		File save = new File("picture");
		FileOutputStream fos =  new FileOutputStream(save);
		
		fos.write(bytes);
		fos.close();
		if(tk.prepareImage(image.getImage(), 900, 900, null)){
			System.out.println("True");
		}else
			System.out.println("False");
The file i output to shows that the image is corrupt, only a few lines of the image are visible and the rest is black. tk.prepareImage() also returns false. This segment sits in a method called once in its class's constructor method. I'm contacting the maps.google server for a map image with the proper parameters. The image returns fine with the same url in a browser . I've checked the google maps API documentation but nothing stands out. Any ideas?


Edit: Attempted requesting a different image format, but now i get "Premature end of JPEG file"
 
Last edited:

Answers and Replies

  • #2
gabbagabbahey
Homework Helper
Gold Member
5,002
6
This is the segment of code causing the error.

Code:
URLConnection con = new URL("www.example.com").openConnection();
		InputStream is = con.getInputStream();
		byte bytes[] = new byte[con.getContentLength()];
		
		BufferedInputStream bis = new BufferedInputStream(is);
		bis.read(bytes);
		bis.close();
		con.getInputStream().close();
		
		Toolkit tk = getToolkit();
		
		image.setImage(tk.createImage(bytes));
		File save = new File("picture");
		FileOutputStream fos =  new FileOutputStream(save);
		
		fos.write(bytes);
		fos.close();
		if(tk.prepareImage(image.getImage(), 900, 900, null)){
			System.out.println("True");
		}else
			System.out.println("False");
The file i output to shows that the image is corrupt, only a few lines of the image are visible and the rest is black. tk.prepareImage() also returns false. This segment sits in a method called once in its class's constructor method. I'm contacting the maps.google server for a map image with the proper parameters. The image returns fine with the same url in a browser . I've checked the google maps API documentation but nothing stands out. Any ideas?


Edit: Attempted requesting a different image format, but now i get "Premature end of JPEG file"
This seems like a really convoluted way to grab an image from a URL. If the URL contains nothing but the image, why not just use something like
Code:
try {
    Image image = tk.createImage(new URL("www.example.com"));
} catch (//whatever exceptions URL's constructor & ToolKit.createImage(URL u) throw) {
    //handle exceptions
}
 
Last edited:
  • #3
25
0
I figured it out. Your way is a lot easier, I'm just used to doing things on a much lower level (C programmer). The stream reader would only read what was available() into the array and not the full contentLength() but a while check sum loop read the full content.
 

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