[COMPRESS-502] Allow to disable closing files in the finalizer of ZipFile

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.19
• Component/s: Compressors
• Assignee: Unassigned
• Reporter: Dominik Stadler
• Created: 22/Jan/20 19:27
• Updated: 17/Mar/23 21:24

Description

Apache POI uses commons-compress for handling ZipFiles. We found that it sometimes does some auto-close magic in the finalizer of the ZipFile class with printing out to stderr, see https://gitbox.apache.org/repos/asf?p=commons-compress.git;a=blob;f=src/main/java/org/apache/commons/compress/archivers/zip/ZipFile.java;h=23194560dace91d8052626f3bdc8f765f9c46d7e;hb=HEAD#l652.

 

This has some shortcomings:

• It prints to stderr which many large-scale applications try to avoid by using some logging framework, thus this output might "vanish" unseen in some installations or might cause unexpected side-effects
• It prevents us from using tools for checking file leaks, e.g. we use https://github.com/kohsuke/file-leak-detector/ heavily for analyzing test-runs for leaked file-handles, but commons-compress prevents this because it "hides" the unclosed file from this functionality
• The behavior of automatic closing and reporting the problem is non-reproducible because it depends on finalizer/garbage-collection and thus any re-runs or unit-tests usually do not show the same behavior

 

There are some fairly simple options to improve this:

• Allow to disable this functionality via configuration/system-property/...
• Make this "pluggable" so a logging-framework can be plugged-in or closing can be prevented for certain runs

 

I can provide a simple patch if you state which approach you think would make most sense here.

 

Issue Links

• is related to: COMPRESS-473 Avoiding Java native peer objects that override finalize()
• is related to: COMPRESS-635 switch system.err/system.out printlns to be log4j or slf4j logging