@Validated - Default member variable values not filled

[derTobsch]

Spring Boot 1.5.1/1.4.4

I tried the @validated annotation as explained in the changelog of spring boot 1.5.1. I tried it with both version 1.4.4 and 1.5.1 and get the same exception. So before @validated will be mandatory I wanted to share my experiences.

@ConfigurationProperties validation

If you have @ConfigurationProperties classes that use JSR-303 constraint annotations, you should now additionally annotate them with @validated. Existing validation will currently continue to work, however, a warning will be logged. In the future, classes without @validated will not be validated at all.

I started a project with own spring boot starters and everything was fine until I started to use the @validated annotation. Since then the PropertiesConfigurationFactory in line 348 contains errors on validating my ConfigurationProperties because every member variables are "empty". Strings are null and ints are 0. dataBinder->bindingResult->target in the PropertiesConfigurationFactory contains only the default values of the types.
This seems to be some bug with cglib? It feels like that the proxy is not correctly instantiated or the validation is to early?
I tried to reproduce this with a small sample project but I could not recreate it.

Maybe you got some idea, what it could be. Maybe something with aop and cglib?

@Validated
@ConfigurationProperties("coffeenet.logging.file")
public class CoffeeNetLoggingFileProperties {

    @NotBlank(message = "Please provide a file where your logs will be written e.g. logs/app.log")
    private String file = "logs/app.log";

    @NotBlank(message = "Please provide a file name pattern with a date pattern e.g. logs/app-%d{yyyy-MM-dd}.log")
    private String fileNamePattern = "logs/app-%d{yyyy-MM-dd}.log";

    @Min(value = 1, message = "Only positive integers are allowed for the maximum amount of history files.")
    @NotNull(message = "Please provide a maximum amount of history files you want to keep.")
    private int maxHistory = 30;

// getters and setters

Will be injected into a AutoConfiguration and exposed as bean through @EnableConfigurationProperties on the class level of the AutoConfiguration.

With the output

***************************
APPLICATION FAILED TO START
***************************

Description:

Binding to target coffee.synyx.autoconfigure.logging.CoffeeNetLoggingFileProperties@1548b9a4 failed:

    Property: coffeenet.logging.file.fileNamePattern
    Value: null
    Reason: Please provide a file name pattern with a date pattern e.g. logs/app-%d{yyyy-MM-dd}.log

    Property: coffeenet.logging.file.file
    Value: null
    Reason: Please provide a file where your logs will be written e.g. logs/app.log

    Property: coffeenet.logging.file.maxHistory
    Value: 0
    Reason: Only positive integers are allowed for the maximum amount of history files.


Action:

Update your application's configuration

[wilkinsona]

@derTobsch Thanks for the analysis

This seems to be some bug with cglib? It feels like that the proxy is not correctly instantiated or the validation is to early?

This is interesting. What makes you think that CGLib is involved?

By default a proxy will not be created for a configuration properties bean. I deliberately did something daft and added @EnableAsync(proxyTargetClass=true) to a main configuration class and added @Async to a getter on a configuration properties class to force it to be proxied. I didn't have any problems with validation. This is what I'd expect as AbstractAdvisingBeanPostProcessor creates the proxy in postProcessAfterInitialization whereas configuration property binding and validation is done in postProcessBeforeInitialization.

I tried to reproduce this with a small sample project but I could not recreate it.

Unfortunately, I think we're going to need a sample (it needn't be small) as it's not obvious how you're getting into a situation where a configuration properties bean has been proxied before it's being validated.

[derTobsch]

This is interesting. What makes you think that CGLib is involved?

because when I debug into the code at PropertiesConfigurationFactory the dataBinder->bindingResult->target, which should be the my ConfigurationProperty class is of coffee.synyx.autoconfigure.logging.CoffeeNetLoggingFileProperties$$EnhancerBySpringCGLIB$$5ae1eaca@6128 and there a several properties called GLIB$CALLBACK_1 to GLIB$CALLBACK_$n and CGLIB$BOUND is false.

I debugged into postProcessAfterInitialization and when one of my ConfigurationProperties comes along with @validated the if conditions isEligible(bean, beanName) and !proxyFactory.isProxyTargetClass() are both true and it runs into

		if (isEligible(bean, beanName)) {
			ProxyFactory proxyFactory = prepareProxyFactory(bean, beanName);
			if (!proxyFactory.isProxyTargetClass()) {
				evaluateProxyInterfaces(bean.getClass(), proxyFactory);
			}
			proxyFactory.addAdvisor(this.advisor);
			customizeProxyFactory(proxyFactory);
			return proxyFactory.getProxy(getProxyClassLoader());
		}

The return statement in line 90 returns

{coffee.synyx.autoconfigure.web.CoffeeNetWebProperties$$EnhancerBySpringCGLIB$$8b0e1d06@7591} "coffee.synyx.autoconfigure.web.CoffeeNetWebProperties@553da911"
 CGLIB$BOUND = false
 CGLIB$CALLBACK_0 = {org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor@7603} 
 CGLIB$CALLBACK_1 = {org.springframework.aop.framework.CglibAopProxy$StaticUnadvisedInterceptor@7604} 
 CGLIB$CALLBACK_2 = {org.springframework.aop.framework.CglibAopProxy$SerializableNoOp@7605} 
 CGLIB$CALLBACK_3 = {org.springframework.aop.framework.CglibAopProxy$StaticDispatcher@7606} 
 CGLIB$CALLBACK_4 = {org.springframework.aop.framework.CglibAopProxy$AdvisedDispatcher@7607} 
 CGLIB$CALLBACK_5 = {org.springframework.aop.framework.CglibAopProxy$EqualsInterceptor@7608} 
 CGLIB$CALLBACK_6 = {org.springframework.aop.framework.CglibAopProxy$HashCodeInterceptor@7609} 
 profileServiceName = null
 logoutPath = null

The logoutPath and the profileServiceName has default values.

@Validated
@ConfigurationProperties("coffeenet.web")
public class CoffeeNetWebProperties {

    @NotEmpty
    private String profileServiceName = "profile";

    @NotEmpty
    private String logoutPath = "/logout";

//getters and setters

I am not familiar with the cglib and how spring works with it, so I hope I could give you some information. I see what I can do to create starters or open source ours to have a sample project. When you need further information just ask and I see what I can do for you :)

I hope I can provide a sample project.

[wilkinsona]

@derTobsch Thanks. That aligns with what I attempted to describe above and with what I am seeing. The key thing is that the proxying happens in postProcessAfterInitialization when the validation should already have occurred during postProcessBeforeInitialization. I don't understand why that's apparently not the case and I think I'll need to see a sample to get to the bottom of it.

[OrangeDog]

I think I've got the same thing, here's the logging that I get:

[ERROR] [main] 16:37:59.482 PropertiesConfigurationFactory - Properties configuration failed validation
[ERROR] [main] 16:37:59.482 PropertiesConfigurationFactory - Field error in object 'myconfig' on field 'key': rejected value [null]; codes [NotNull.myconfig.key,NotNull.key,NotNull.java.lang.String,NotNull]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [myconfig.key,key]; arguments []; default message [key]]; default message [may not be null]
[WARN] [main] 16:37:59.483 AnnotationConfigEmbeddedWebApplicationContext - Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'myConfig': Could not bind properties to MyConfig (prefix=myconfig, ignoreInvalidFields=false, ignoreUnknownFields=true, ignoreNestedProperties=false); nested exception is org.springframework.validation.BindException: org.springframework.boot.bind.RelaxedDataBinder$RelaxedBeanPropertyBindingResult: 1 errors
[ERROR] [main] 16:38:01.721 LoggingFailureAnalysisReporter - 

***************************
APPLICATION FAILED TO START
***************************

Description:

Binding to target MyConfig(key=xxxxxxxxxxxxxxxxxxxx) failed:

    Property: myconfig.key
    Value: null
    Reason: may not be null

Note the inconsistent reporting of whether the property was null or not.

I tried extracting an interface from the class and injecting with that, but it got worse:

[ERROR] [main] 16:32:51.301 SpringApplication - Application startup failed
java.lang.NullPointerException: null
    at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor$ValidatedLocalValidatorFactoryBean.supports(ConfigurationPropertiesBindingPostProcessor.java:423)
    at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.determineValidator(ConfigurationPropertiesBindingPostProcessor.java:353)
    at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.postProcessBeforeInitialization(ConfigurationPropertiesBindingPostProcessor.java:314)
    at org.springframework.boot.context.properties.ConfigurationPropertiesBindingPostProcessor.postProcessBeforeInitialization(ConfigurationPropertiesBindingPostProcessor.java:296)
    at org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder.rebind(ConfigurationPropertiesRebinder.java:100)
    at org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder.rebind(ConfigurationPropertiesRebinder.java:88)
    at org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder.onApplicationEvent(ConfigurationPropertiesRebinder.java:120)
    at org.springframework.cloud.context.properties.ConfigurationPropertiesRebinder.onApplicationEvent(ConfigurationPropertiesRebinder.java:49)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:167)
    at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:139)
    at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:383)
    at org.springframework.context.support.AbstractApplicationContext.publishEvent(AbstractApplicationContext.java:337)
    at org.springframework.cloud.autoconfigure.ConfigurationPropertiesRebinderAutoConfiguration.afterSingletonsInstantiated(ConfigurationPropertiesRebinderAutoConfiguration.java:79)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:781)
    at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:866)
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:542)
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122)
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:737)
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:370)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:314)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1162)
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1151)
    at com.example.Application.main(Application.java:39)

AFAIKT it was the getPackage() call that returned null, because the type was com.sun.proxy.$Proxy149.

In my case, @ConfigurationProperties is not on the class, but on the @Bean method.
I think the proxy is added because I already have a BeanValidationPostProcessor adding MethodValidationInterceptor advice.