It is intrusive and aggressive to close not owned input/output stream by default

[kezhuw]

In 2.x, JsonParser and JsonGenerator enable JsonParser.Feature.AUTO_CLOSE_SOURCE and JsonGenerator.Feature.AUTO_CLOSE_TARGET by default. I think it is too intrusive and aggressive to enable these features by default since they operate on input/output stream not owned by parser/generator as the javadoc states.

Besides this, I found YAMLGenerator closes input/output stream always without consulting these features. This makes me can't use ObjectMapper.writeValue(OutputStream out, Object value) to write yaml content embedded in another stream, say zipped file stream.

PS: I saw these features are migrated to StreamReadFeature and StreamWriteFeature in master.

[cowtowncoder]

On YAML, this:

FasterXML/jackson-dataformats-text#99

was the issue; fixed now in 2.9.8. It's a good idea to report these directly for project.

We can definitely consider default settings for 3.0, but the reason for these settings is that I experienced the opposite pain when frameworks like Stax (XML API) did the opposite and left hanging file handles, sometimes running out and causing service failures. So there is a reason why default is that way.

Same is true for some other features, such as "fail on unknown properties": debugging problems when nothing matches is annoying. But I can see how the opposite setting can be problematic as well.

One thing I'll need to figure out is how to collect all ideas for changing defaults. I think they should be considered as a group, as sort of "Jackson Improvement Project" or something, for bigger v3 changes/additions.