Rejected value is null when configuration property fails validation

[tazle]

After changing from Spring Boot 2.1.9 to Spring Boot 2.2.2, the error messages about constraint validation for some of our configuration properties started including null as the rejected value, rather than the actual value (-1 in this case).

The root cause seems to be that SpringValidationAdapter's getRejectedValue(ield, violation, bindingResult) has started returning null in certain cases with the bindingResult that's present in 2.2.2. Or rather, the getRawFieldValue(String) has started returning null.

Failing case in 2.2.2:
SpringValidationAdapter calls ValidationBindHandlers$ValidationResult.getRawFieldValue("intermediatefield.leafFieldInCamelCase")which returns null because it expects field names in form "intermediatefield.leaf-field-in-camel-case".

Working case in 2.1.9:
SpringValidationAdapter calls BeanPropertyBindingResult.getRawFieldValue("intermediatefield.leafFieldInCamelCase") which returns the actual field value.

I'll try to produce a minimal reproduction later.

[mbhave]

@tazle A sample that we can use to reproduce the issue would be very helpful, thanks.

[tazle]

Reproducer:
pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
	<modelVersion>4.0.0</modelVersion>
	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>2.2.2.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>
	<groupId>com.example</groupId>
	<artifactId>repro_19580</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<name>repro_19580</name>
	<description>Demo project for Spring Boot</description>

	<properties>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter</artifactId>
		</dependency>

		<dependency>
			<groupId>org.hibernate.validator</groupId>
			<artifactId>hibernate-validator</artifactId>
			<version>6.0.18.Final</version>
		</dependency>

		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
			<exclusions>
				<exclusion>
					<groupId>org.junit.vintage</groupId>
					<artifactId>junit-vintage-engine</artifactId>
				</exclusion>
			</exclusions>
		</dependency>
		<dependency>
			<groupId>javax.validation</groupId>
			<artifactId>validation-api</artifactId>
			<version>2.0.1.Final</version>
		</dependency>
	</dependencies>

	<build>
		<plugins>
			<plugin>
				<groupId>org.springframework.boot</groupId>
				<artifactId>spring-boot-maven-plugin</artifactId>
			</plugin>
		</plugins>
	</build>

</project>

src/main/java/com/example/repro_19580/Repro19580Application.java:

package com.example.repro_19580;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.stereotype.Component;
import org.springframework.validation.annotation.Validated;

import javax.validation.Valid;
import javax.validation.constraints.Min;
import java.lang.invoke.MethodHandles;

@ConfigurationProperties(prefix = "inner")
@Validated
class InnerProperties {
	@Min(0)
	private int camelCaseValue = 0;

	public int getCamelCaseValue() {
		return camelCaseValue;
	}

	public void setCamelCaseValue(final int camelCaseValue) {
		this.camelCaseValue = camelCaseValue;
	}
}

@ConfigurationProperties("test")
@Validated
class TestProperties {
	@Valid
	InnerProperties inner = new InnerProperties();

	public InnerProperties getInner() {
		return inner;
	}
}

@SpringBootApplication
@EnableConfigurationProperties(TestProperties.class)
@Component
public class Repro19580Application {
	private final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());

	@Autowired
	TestProperties props;

	public static void main(String[] args) {
		ConfigurableApplicationContext ctx = SpringApplication.run(Repro19580Application.class, args);
		ctx.getBean(Repro19580Application.class).checkValue();
	}

	void checkValue() {
		log.info("Configured value is: {}", props.getInner().getCamelCaseValue());
	}
}

To reproduce:
mvnq package && java -jar target/repro_19580-0.0.1-SNAPSHOT.jar --test.inner.camel-case-value=-1

[snicoll]

@tazle thank you for the sample but rather than code in text, please create a project (either a github project or a zip) as we'd have to copy paste all that in order to do something useful with it anyway.

[tazle]

Zipped up:

repro_19580.zip

[nosan]

Looks like gh-17424 is a cause. ValidationBindHandler$ValidationResult.getActualFieldValue does not work at all if the provided value is in a camelCase format:

org.springframework.boot.context.properties.source.InvalidConfigurationPropertyNameException: Configuration property name 'camelCaseValue' is not valid
	at org.springframework.boot.context.properties.source.ConfigurationPropertyName.elementsOf(ConfigurationPropertyName.java:522)
	at org.springframework.boot.context.properties.source.ConfigurationPropertyName.probablySingleElementOf(ConfigurationPropertyName.java:495)
	at org.springframework.boot.context.properties.source.ConfigurationPropertyName.append(ConfigurationPropertyName.java:191)
	at org.springframework.boot.context.properties.bind.validation.ValidationBindHandler$ValidationResult.getName(ValidationBindHandler.java:190)
	at org.springframework.boot.context.properties.bind.validation.ValidationBindHandler$ValidationResult.getFieldType(ValidationBindHandler.java:168)
	at org.springframework.validation.AbstractBindingResult.resolveMessageCodes(AbstractBindingResult.java:325)
	at org.springframework.validation.beanvalidation.SpringValidatorAdapter.processConstraintViolations(SpringValidatorAdapter.java:175)
	at org.springframework.validation.beanvalidation.SpringValidatorAdapter.validate(SpringValidatorAdapter.java:109)
	at org.springframework.boot.context.properties.ConfigurationPropertiesJsr303Validator.validate(ConfigurationPropertiesJsr303Validator.java:51)
	at org.springframework.boot.context.properties.bind.validation.ValidationBindHandler.validateAndPush(ValidationBindHandler.java:132)
	at org.springframework.boot.context.properties.bind.validation.ValidationBindHandler.validate(ValidationBindHandler.java:110)
	at org.springframework.boot.context.properties.bind.validation.ValidationBindHandler.onFinish(ValidationBindHandler.java:102)
	at org.springframework.boot.context.properties.bind.Binder.handleBindResult(Binder.java:340)
	at org.springframework.boot.context.properties.bind.Binder.bind(Binder.java:321)

problem line:

spring-boot/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/validation/ValidationBindHandler.java

Line 190 in c584334

return this.name.append(field);

Btw, I have found that

spring-boot/spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/properties/bind/validation/ValidationBindHandler.java

Line 180 in c584334

protected Object getActualFieldValue(String field) {

catches an exception but just swallows it, and that's why this issue was hidden from folks :( Maybe it makes sense at least to log it in DEBUG level.

This issue can be easily fixed with:

			return this.name.append(DataObjectPropertyName.toDashedForm(field));

But I am not sure about this and in addition DataObjectPropertyName is a package-private class.