Addition of fallback patterns to temporal parser loses cause in Spring 5.3.5

[petergphillips]

Affects: 5.3.5

We've just pulled in the latest spring framework as a result of a spring boot upgrade to 2.4.4 and noticed that some of our unit tests are now failing as the error messages have now changed.

When we detect a validation failure our code calls e.getMostSpecificCause().getMessage() to get the reason for the failure. So for input value of 2019-30-17 we expect to get the error message of

Invalid value for MonthOfYear (valid values 1 - 12): 30

as that is what the root DateTimeException message is set to.

However it appears that changes for #20292 create a brand new DateTimeParseException without passing in the cause into the constructor on creation. This can be seen at

spring-framework/spring-context/src/main/java/org/springframework/format/datetime/standard/TemporalAccessorParser.java

Line 102 in b2bcb0f

throw new DateTimeParseException(

and should be changed to pass through the existing DateTimeException cause.

This means that the error message we now get is

Unable to parse date time value "2019-30-17" using configuration from @org.springframework.format.annotation.DateTimeFormat(pattern="", style="SS", iso=DATE, fallbackPatterns={})

which isn't nearly as human readable as the original, divulges inner spring annotations, and isn't suitable for end users. I understand that there is a desire to output the fallbackPatterns in case there are multiple specified, but I would have expected the underlying cause to be preserved so that applications can choose which cause to present to the user. Furthermore I wouldn't expect patch versions of spring to change the validation error messages.

In our spring boot code the field is annotated with

@DateTimeFormat(iso = ISO.DATE) @RequestParam(value = "from_date", required = false) LocalDate fromDate

[sbrannen]

Thanks for bringing this to our attention!

This has been fixed in 22d9012 and will be available in Spring Framework 5.3.6.

[petergphillips]

thanks for the quick fix @sbrannen. Whilst not affecting us I did also notice that

spring-framework/spring-context/src/main/java/org/springframework/format/datetime/DateFormatter.java

Lines 222 to 224 in b2bcb0f

	throw new ParseException(
	String.format("Unable to parse date time value \"%s\" using configuration from %s", text, this.source),
	ex.getErrorOffset());

was added at the same time as the other change and is also missing the root cause too.

[sbrannen]

was added at the same time as the other change and is also missing the root cause too.

I actually noticed that on my own (unfortunately after the 5.3.6 release), created #26804 to address it, and just came back here to point people to that issue as well... only to notice your comment after the fact. 😉

Cheers!