How to get Spring Boot to create a bean validator before creating all the other beans - spring

I'm trying to add a LocalValidatorFactoryBean to an existing Spring Boot web application.
No matter what I have tried (listed in a moment) it only creates the validator after most other beans (verified with both logging and breakpoints), so they never get validated.
Tangentially, I have hibernate-validator on the classpath and am attempting to use javax.validation.constraints on my #Component properties.
Application class has #Configuration, #EnableAutoConfiguration and #ComponentScan({"my.package.**"}).
Adding an application.xml with the bean <bean id="validator" class="org.springframework.validation.beanvalidation.LocalValidatorFactoryBean"/>
Adding the above bean to validator.xml and adding #ImportResource("validator.xml")
Adding a new #Bean to the Application class. public Validator validator() { return new LocalValidatorFactoryBean(); }
Adding #Order(Ordered.HIGHEST_PRECEDENCE) to the above #Bean
Adding a BeanValidator #Component to the scanned packages.
And adding #Order to it.
In all cases, the validator is loaded only after FilterRegistrationBean has finished logging its business, but the beans I want to validate have already been created and used in setting up data connections and security for example.
Its been a few years since I've used Spring, but I don't remember these problems when defining everything in an application.xml. Is this just something that spring-boot doesn't support and I should move back to traditional Spring application config?
How can I get it to validate all my beans?

I forgot to make a BeanValidationPostProcessor.

Related

Facing issue while adding Springdoc-openapi in Spring Framework based project (Not Spring Boot)

We have Spring framework (version 5.3.22) based application, not a spring boot.
We have added springdoc-openapi (1.6.11) dependency along with below openapi configuration.
#Configuration
#EnableWebMvc
#ComponentScan(basePackages = {"org.springdoc"})
#Import({org.springdoc.core.SpringDocConfiguration.class,
org.springdoc.webmvc.core.SpringDocWebMvcConfiguration.class,
org.springdoc.webmvc.ui.SwaggerConfig.class,
org.springdoc.core.SwaggerUiConfigProperties.class,
org.springdoc.core.SwaggerUiOAuthProperties.class,
org.springframework.boot.autoconfigure.jackson.JacksonAutoConfiguration.class})
public class OpenApiConfig implements WebMvcConfigurer { }
In our application, we have multiple projects having mixed of Java configurations and XML based configurations.
Both types of classes (java config like #controller/#service and XML definitions like <bean id="".... >) are having dependencies injected through #Autowired.
The classes having beans created through component scanning (#controller/#service) are working well, all the injected dependecies are resolved as expected.
But the classes having XML definitions are having issues, where dependencies injected through setter and bean ref are working fine, but the dependencies injected through #Autowired are found as null at runtime. Looks like #Autowired annotation itself is not getting resolved while creating bean of such classes. We have also verified that our XML context file has <context:annotation-config /> defined and so #Autowired should get resolved here.
Without this springdoc-openpi dependency and these OpenApiConfig, we are not facing this issue.
Does anyone have more insights here ?

Split jackson configuration into separate properties

I'm using Spring Boot 2.2.5.RELEASE and would like to split my application.properties into separate files. There are already similar questions on StackOverflow but none of them seem to work for configuring Jackson.
My current non working solution is the following:
root/
- application.properties (without Jackson configuration)
- jackson-configuration.properties (includes Jackson configuration)
Jackson configuration class:
#Configuration
#PropertySource("/jackson-configuration.properties")
public class JacksonConfiguration {
}
Please note, I've tried different ways to specify the path including:
"/jackson-configuration.properties"
"jackson-configuration.properties"
"classpath:/jackson-configuration.properties"
"classpath:jackson-configuration.properties"
Spring Boot does not seem to use the configuration. If I copy it over into the application.properties - it works.
Content of jackson-configuration.properties:
spring.jackson.property-naming-strategy=SNAKE_CASE
spring.jackson.mapper.sort-properties-alphabetically=true
spring.jackson.deserialization.fail-on-unknown-properties=true
spring.jackson.parser.strict-duplicate-detection=true
spring.jackson.time-zone=Europe/Zurich
My application is annotated with #SpringBootApplication , so it should scan for additional properties.
/edit
I just realized the problem is the testing, not the productive code itself. If I start the application it works. What doess not work is testing with #JsonTest. I can fix this problem by adding the following line to my tests #ContextConfiguration(classes = {JacksonConfiguration.class}). But in turn, this causes the annotation #JsonComponent to stop working but only for the #JsonTest annotated classes.
See the documentation here. Here is an excerpt from the documentation
In order to resolve ${...} placeholders in definitions or
#Value annotations using properties from a PropertySource, you must
ensure that an appropriate embedded value resolver is registered in
the BeanFactory used by the ApplicationContext. This happens
automatically when using in XML. When
using #Configuration classes this can be achieved by explicitly
registering a PropertySourcesPlaceholderConfigurer via a static #Bean
method.
You need to create a bean like this
#Bean
public static PropertySourcesPlaceholderConfigurer devPropertyPlaceholderConfigurer() throws IOException {
PropertySourcesPlaceholderConfigurer configurer = new PropertySourcesPlaceholderConfigurer();
configurer.setLocations(new PathMatchingResourcePatternResolver().getResources("file:pathtToFile"));
configurer.setIgnoreUnresolvablePlaceholders(true);
return configurer;
}

How SpringBoot dependency injection works with different type of annotations

I recently started exploring Spring Boot. I see that there are 2 ways to define Beans in Spring Boot.
Define #Bean in the class annotated with #SprinBootApplication
Define #Bean in a class annotated with #Configuration
I am also confused about stereo-type annotation #Repository #Service #Controller etc.
Can someone please explain how dependency-injection works with these annotations?
Yes it is possible.
Either you use #Bean in any of your #Configuration or #SpringBootApplication class or mark the bean classes explicitly with annotations like #Service, #Component #Repository etc.
#Service or #Component
When you mark a class with #Service or #Compoenent and if spring's annotation scanning scope allows it to reach to the package, spring will register the instances of those classes as spring beans.
You can provide the packages to be included/excluded during scan with #ComponentScan
#Bean
#Beans are marked on factory methods which can create an instance of a particular class.
#Bean
public Account getAccount(){
return new DailyAccount();
}
Now in you application you can simply #Autowire Account and spring will internally call its factory method getAccount, which in turn returns an instance of DailyAccount.
There is a simple difference of using #Bean vs #Service or #Compoenent.
The first one makes your beans loosely coupled to each other.
In the #Bean, you have flexibility to change the account implementation without even changing any of the account classes.
Consider if your classes instantiation is a multi-step operation like read properties values etc then you can easily do it in your #Bean method.
#Bean also helps if you don't have source code access to the class you are trying to instantiate.
Spring Boot auto-configuration attempts to automatically configure your Spring application based on the jar dependencies that you have added.
You need to opt-in to auto-configuration by adding the #EnableAutoConfiguration or #SpringBootApplication annotations to one of your #Configuration classes.
You are free to use any of the standard Spring Framework techniques to define your beans and their injected dependencies. For simplicity, we often find that using #ComponentScan (to find your beans) and using #Autowired (to do constructor injection) works well.
One way is to define #Bean in the class annotated with
#SprinBootApplication
If you see #SprinBootApplication it is combination of many annotation, and one of them is #Configuration. So when you define #Bean in the Main class, it means it's inside #Configuration class.
According to Configuration docs :
Indicates that a class declares one or more #Bean methods and may be
processed by the Spring container to generate bean definitions and
service requests for those beans at runtime.
class annotated with #Configuration
When you define #Bean is a class annotated with #Configuration class, it means it is the part of spring configuration all the Beans define in it all available for Dependency-Injection.
I have also seen some code where neither of the 2 above approaches
have been used and yet dependency injection works fine. I have tried
to research a lot on this but could not find any concrete answer to
this. Is this possible?
I am assuming you are talking about Sterio-type annotation. Every sterio type annotation has #Component, according to docs :
Indicates that an annotated class is a "component". Such classes are
considered as candidates for auto-detection when using
annotation-based configuration and classpath scanning.

Purpose of using #Configuration annotation

I have created a spring mvc based application but I didn't use this #Configuration annotation. What is the purpose of using #Configuration annotation? By using this, what are we communicating to springMVC container?
Assuming your application is using xml configuration rather than AnnotationConfig so it is not loaded to ApplicationContext at all.
#Configuration is used when ApplicationContext has been initialized and bean registration.
#Configuration annotation is a core Spring annotation, and not Spring MVC. It is a core entry point to configuring Spring-based application using Java config instead of XML config.
Please, use Spring Documentation more often because it is a place where you will find answers to most of your questions. Like this one:
Indicates that a class declares one or more Bean #Bean methods and may
be processed by the Spring container to generate bean definitions and
service requests for those beans at runtime

Autowiring Struts Action Classes with Spring

I have a question about spring and struts.
Currently I have spring injecting my struts action classes for me.
I was experimenting and trying to get Spring to inject my Struts action classes
for me using autowiring.
I have my spring applicationContext config file scanning the base package that the
action class is in using context:component-scan base-package="my.package",
and im using #Component annotation at the action classes class level.
Im also using #Qualifier("myActionClass") at the same action classes class level.
Im not configuring the action class as a Spring bean in applicationContext.
Then in my struts.xml config file, while configuring my action class, instead of giving the fully qualified package and class name, I use the #Qualifier annotation name "myActionClass".
This doesnt work though.
If in my applicationContext config file, configure my action class as a spring bean, get rid of the #Component and #Qualifier annotation on the action class, and in struts.xml, put the action classes Spring bean id for the class, then Spring injects my action class for me and everything is dandy. Only, this isnt using Autowiring the action class, and thats what I was testing.
Anyone know if autowiring using context:component-scan base-package
to scan your packages for your action classes so you dont have to configure them in applicationContext is possible?
Everything is explained in Spring documentation: Apache Struts 1.x and 2.x.
I am not sure whether you are using Struts 1 or 2. For Struts 1 you had to add Spring plugin to Struts configuration (I know it works). In Struts 2 all actions are created by Spring hence they are fully capable of Spring injection like all other beans.
Struts 2 seems to rely on there being a spring bean with the same spring bean-name matching the action class name (full name with package). You can specify the bean name in the #Component annotation, and it's also possible to make a global user-defined bean naming strategy so you can avoid adding this information to all your beans

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