PDF and HTML export fails due to 'too many open files' exception

Happened while running an export (HTML) on the doc. space on c.a.c..

Cause:
java.io.IOException: Too many open files

This seems to be because we open file input streams, but don't close them!

An example is:

FileUtils.copyFile(new FileInputStream(attachmentFile), new File(folder.getAbsolutePath() + "/" + attachmentFile.getParentFile().getName()));

AbstractRendererExporterImpl:147

In general, when you don't explicitly close the inputstream, then you will have a file handle leak until the object gets garbage collected.

Searching for all uses of 'FileInputStream' should be able to show which ones aren't closed