Deprecate JsonNode.asText(String) (note: reverted in 2.17.1)

[apeteri]

NOTE: see #4471 for current state -- this was done for 2.17.0 release but reverted for 2.17.1

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Describe the bug

It looks like the fallback value in JsonNode#asText(String) never gets a chance to appear as the 0-arg asText() should never return null, according to its Javadoc:

jackson-databind/src/main/java/tools/jackson/databind/JsonNode.java

Lines 604 to 623 in dca0c27

	/**
	* Method that will return a valid String representation of
	* the container value, if the node is a value node
	* (method {@link #isValueNode} returns true),
	* otherwise empty String.
	*/
	public abstract String asText();
	/**
	* Method similar to {@link #asText()}, except that it will return
	* <code>defaultValue</code> in cases where null value would be returned;
	* either for missing nodes (trying to access missing property, or element
	* at invalid item for array) or explicit nulls.
	*/
	public String asText(String defaultValue) {
	String str = asText();
	return (str == null) ? defaultValue : str;
	}

This seems to be the case in all implementations of asText() I can see, and has been corroborated in other issues such as #25.

The only exception is if someone calls TextNode(String) directly with null as the input. TextNode#valueOf(String) already converts these cases into null references, so the "almost" in the title is quite strong.

Version Information

2.16.1

Expected behavior

Either replace the null check with an emptyness check (but then "legitimate empty" strings will also use the default value), or deprecate the method? Not quite sure!

[cowtowncoder]

Ok explanation makes sense: I'd vote for deprecation. We can do that for 2.17 -- would be happy to get a PR (with Javadoc explaining reasoning).

[cowtowncoder]

Interestingly enough, this method behaves bit different than advertised: "defaultValue" will be returned for all MissingNodes and NullNodes EVEN THOUGH THEIR asText() does NOT return null... uh.

All the more reason to deprecate it, tho, remove from 3.0.

[apeteri]

I didn't get to that one apparently. 😄 Thank you for the fix!

[cowtowncoder]

@apeteri no problem; not a big deal. Thank you for pointing this out.

[cowtowncoder]

Looks like this should be reverted, based on feedback and better understanding on logic & updated description.

[cowtowncoder]

Reverted for 2.17.1 via #4471 .