Document need for -parameters flag in exception messages

[sbrannen]

Overview

Since -parameters is required for certain use cases starting with Spring Framework 6.1, we should revise related exception messages to explicitly mention the solution.

For example, a Spring MVC @Controller handler method with a @PathVariable String client parameter declaration may fail with an exception similar to the following.

java.lang.IllegalArgumentException: Name for argument of type [java.lang.String] not specified, and parameter name information not found in class file either.

To improve diagnostics, we should add something along the lines of Ensure that the compiler uses the -parameters flag. to the end of that exception message.

Related Issues

• Deprecate LocalVariableTableParameterNameDiscoverer completely (avoiding its exposure in native images) #29531
• Remove LocalVariableTableParameterNameDiscoverer #29559
• NoUniqueBeanDefinitionException when constructor/setter parameter name used as qualifier #31643
• SpEL cannot evaluate after update from 6.0.13 to 6.1.1 #31666
• Properties-driven path throws IllegalArgumentException #31671
• Dependency injection in @Bean method with qualifier based on parameter name doesn't work in Spring 6.1 #31685
• IllegalArgumentException: Null key returned for cache operation  #31729
• spring scanning same type bean with different names returning ambiguous exception after upgrading to spring-boot 3.2 #31743

[philwebb]

@sbrannen @bclozel Any thoughts about introducing a dedicated exception type? We could then have a failure analyzer in Spring Boot.

[sbrannen]

Reopening to improve exception message in CacheAspectSupport.generateKey(CacheOperationContext, Object).

• see IllegalArgumentException: Null key returned for cache operation  #31729

[sbrannen]

Any thoughts about introducing a dedicated exception type?

That's an interesting idea.

For some use cases (e.g., mvc controller handler methods, and cache key generation) it would be relatively straightforward; however, for other uses (e.g., SpEL expressions, parameter named used as fallback qualifier for dependency injection by type) it may not be as straightforward to pin down what the trigger would be for such an exception.

In any case, we'll discuss it amongst the team.

[sbrannen]

Note to maintainers

If we modify the exception message currently used or introduce a new exception type, etc., we must make sure that the exception message contains "Ensure that the compiler uses the '-parameters' flag".

Otherwise, we'll render Spring Boot's failure analysis useless, since it depends on the exception message containing exactly that sub-string.

https://github.com/spring-projects/spring-boot/blob/b5de38787c6abd4fc6522aa006b3d460ae23ffc5/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/diagnostics/analyzer/MissingParameterNamesFailureAnalyzer.java#L38