Spring LocalVariableTableParameterNameDiscoverer logs many warnings with Hibernate validation

Affects: 6.0.1

Having a small simple Spring Boot application with Validator dependency, adding a ConfigurationProperties class with @Validated logs many warning like below:

...
2022-11-23T20:36:30.230+01:00  WARN 10246 --- [  restartedMain] ocalVariableTableParameterNameDiscoverer : Using deprecated '-debug' fallback for parameter name resolution. Compile the affected code with '-parameters' instead: public java.lang.String(java.lang.StringBuilder)
2022-11-23T20:36:30.231+01:00  WARN 10246 --- [  restartedMain] ocalVariableTableParameterNameDiscoverer : Using deprecated '-debug' fallback for parameter name resolution. Compile the affected code with '-parameters' instead: public java.lang.String(char[])
2022-11-23T20:36:30.231+01:00  WARN 10246 --- [  restartedMain] ocalVariableTableParameterNameDiscoverer : Using deprecated '-debug' fallback for parameter name resolution. Compile the affected code with '-parameters' instead: java.lang.String(char[],int,int,java.lang.Void)
2022-11-23T20:36:30.231+01:00  WARN 10246 --- [  restartedMain] ocalVariableTableParameterNameDiscoverer : Using deprecated '-debug' fallback for parameter name resolution. Compile the affected code with '-parameters' instead: java.lang.String(char[],int,int,java.lang.Void)
2022-11-23T20:36:30.231+01:00  WARN 10246 --- [  restartedMain] ocalVariableTableParameterNameDiscoverer : Using deprecated '-debug' fallback for parameter name resolution. Compile the affected code with '-parameters' instead: java.lang.String(char[],int,int,java.lang.Void)
...

I'm not entirely sure what it's saying. The executable is not my code, it's the standard library. Anyway, adding javaParameters = true to the build script doesn't help. I started seeing the logs after refreshing the snapshot version of Spring Boot (but Spring Core is v6.0.1). There was no issue before. sample-project

Comment From: sdeleuze

It is a side effect of fe5bd6751f461532d6817610c47254e0400d25f9 when Hibernate Validator is used. I can reproduce with both Kotlin and Java.

Here we have org.springframework.boot.context.properties.ConfigurationPropertiesJsr303Validator -> jakarta.validation.Validator.validate("Foooooo") -> org.hibernate.validator.internal.metadata.BeanMetaDataManagerImpl.createBeanMetaData(String.class) -> org.hibernate.validator.internal.metadata.aggregated.BeanMetaDataBuilder#build where here there are 107 builders (String constructors and methods).

They come from org.hibernate.validator.internal.metadata.provider.AnnotationMetaDataProvider#retrieveBeanConfiguration which adds all methods and all constructors of the types validated, and then org.hibernate.validator.internal.util.ExecutableParameterNameProvider delegates to org.springframework.validation.beanvalidation.LocalValidatorFactoryBean which in turn delegates to org.springframework.core.LocalVariableTableParameterNameDiscoverer on String JDK class not compiled with -parameters.

Comment From: emeraldhieu

This still happens in spring 6.0.2. Spring Boot 3.0.0.

Comment From: plause

This still happens in spring 6.0.2. Spring Boot 3.0.0.

Adding -java-parameters(Kotlin)/-parameters(Java) flag to the compiler options helps get rid of these warnings.

tasks.withType<KotlinCompile> {
    kotlinOptions {
        freeCompilerArgs = listOf("-java-parameters")
    }
}

compileJava {
    options.compilerArgs << '-parameters'
}

Note: you should read/know the Drawbacks of javac -parameters flag