Close StreamResource

Marc Poy

Hi all,

maybe I'm overthinking things but I used to learn whenever I have a resoruce Input/Output I'll do a try-finllay block to close the resource at the end.
In this case I try to display a PDF from a byte array.

For this I create a StreamResource:

StreamResource pdfResource = new StreamResource(
  () -> new ByteArrayInputStream(pdfContent),
  filename
);

I now wonder where and how to close the InputStream. I don't want to have a blocked Resource in the Memmory of the server.
Do I have to do this manualy or does the Vaadin-Framework close the given Resources once the ConnectorResource/StreamResouce is not used anymore.

I found following Documentation but that isn't really clear on the process: https://dev.vaadin.com/wiki/Vaadin7/Features/ConnectorResource

Thanks for any advice

Petrus Viljoen

It should be closed by DownloadStream.writeResponse if I'm not mistaken.

It is simple to test if close is called properly though.

StreamResource pdfResource = new StreamResource(
  () -> new ByteArrayInputStream(pdfContent) {
       public void close() throws IOException {
            LOGGER.fine("StreamResource closing");
            super.close();
       }
  },
  filename
);

But as a side note, ByteArrayInputStream.close does nothing, and the ByteArrayInputStream does not hold onto any system resources(other than the original byte[]) so the garbage collector should be able to remove if safely once it is dereferenced.

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Close StreamResource

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