MissingKotlinParameterException should extend MismatchedInputException #321
Description
Should MissingKotlinParameterException extend MismatchedInputException?
The javadoc of MismatchedInputException suggests that MissingKotlinParameterException is a valid subtype:
/**
* General exception type used as the base class for all {@link JsonMappingException}s
* that are due to input not mapping to target definition; these are typically
* considered "client errors" since target type definition itself is not the root cause
* but mismatching input. This is in contrast to {@link InvalidDefinitionException} which
* signals a problem with target type definition and not input.
*<p>
In a recent version of Spring, a change was introduced that differentiate handling of exceptions when parsing a HTTP input:
https://github.com/spring-projects/spring-framework/blob/b889700548681382911e06701b257549bb81e929/spring-web/src/main/java/org/springframework/http/converter/json/AbstractJackson2HttpMessageConverter.java#L242
catch (MismatchedInputException ex) { // specific kind of JsonMappingException
throw new HttpMessageNotReadableException("Invalid JSON input: " + ex.getOriginalMessage(), ex, inputMessage);
}
catch (InvalidDefinitionException ex) { // another kind of JsonMappingException
throw new HttpMessageConversionException("Type definition error: " + ex.getType(), ex);
}
catch (JsonMappingException ex) { // typically ValueInstantiationException
throw new HttpMessageConversionException("JSON conversion problem: " + ex.getOriginalMessage(), ex);
}
catch (JsonProcessingException ex) {
throw new HttpMessageNotReadableException("JSON parse error: " + ex.getOriginalMessage(), ex, inputMessage);
}
Basically, if Jackson throws MismatchedInputException our controllers respond with 400 Bad Request, otherwise they respond with 500 Internal Server Error.
Because of this change, Kotlin dtos cannot be properly rejected when a non-nullable constructor argument is missing.
An example problem it causes:
spring-projects/spring-framework#24610