Unable to override writeObjectFieldValueSeparator in DefaultPrettyPrinter

[chuwy]

I tried to override writeObjectFieldValueSeparator method to output colon without space before it, like it described in Jackson Cookbook in "Custom Pretty Printer":

@Override
public void writeObjectFieldValueSeparator(JsonGenerator jg) throws IOException, JsonGenerationException {
    jg.writeRaw(": ");
}

And it seems it does not even called (judging by print statements).
On the other hand, this trick with MinimalPrettyPrinter works fine.

[cowtowncoder]

I would need a unit test to reproduce this.

[chuwy]

Ok. I'll provide it tomorrow.
Until now only this solutions works for me: https://gist.github.com/chuwy/84ed38389b50d766f17f which isn't looks good anyway: I need to copy-paste almost whole DefaultPrettyPrinter class to only eliminate space before a colon.

[maxshort]

I think this due to the fact that DefaultPrettyPrinter is of type Instantiable which means it has a createInstance method which is meant to copy the DefaultPrettyPrinter. ObjectWriter calls createInstance on the extended CustomPrettyPrinter which returns a DefaultPrettyPrinter.

The reason that the gist above works is that it overrides createInstance. Not sure if this is a bug or just needs more documentation.

[cowtowncoder]

@maxshort Good point -- createInstance() absolutely does need to be overridden, both to return proper subtype instance when it is called, and (if implementation just returned this), to avoid clashes.

@chuwy I think explanation above is correct: you need to override createInstance() to return instance of your sub-class.