field annotated with `#value` is not initialized in mongock configuration - java

I need to assure data migration using mongock.
The #ChangeUnit class holds the logic for migration. It has a field annotated with #Value which is always null, even though I properly initialized in application.properties:
mongock.migration-scan-package=my.package
login-secret=test
Then the MigrationConfiguration looks as follows:
#ChangeUnit(id = "test", order = "001", author = "test")
#RequiredArgsConstructor
#Configuration
public class InitUsersChangeLog {
private final MyService service;
private final MongoTemplate template;
#Value("${login-secret}")
private String LOGIN;
#Execution
public void initUser() {
service.create(User.builder().login(LOGIN).build());
}
}
Main class:
#EnableMongock
#SpringBootApplication
public class MailServiceApplication {...}
My assumption is that this value is not injected properly into the MongockConfiguration bean. I tried to configure the bean manually (without using mongock.migration-scan-package=my.package) in the properties, but with no success.

As Mongock currently doesn't support #Value annotation you can try to use getProperty method from Environment bean. Environment bean can be injected same as other beans using constructor or Lombok annotations.
You want to change this:
#Value("your.key.property")
to that:
private final Environment env;
public void method(){
env.getProperty("your.key.property")
}

Mongock currently no supports #value injection via field o method parameter. We will provide that in a future minor release within version 5, but we can't give you dates, yet.

Extending MichalJ's answer, which is absolutely valid. I would like to add that the changeUnits are not retrieved by Mongock via Springboot, they are processed by Mongock independently. So the annotation #Configuration, #Component, etc. won't be taken into account and they could even be damaging.
Related to that, this code won't work, at least not in a near future:
#Value("${login-secret}")
private String LOGIN;
First, as said, Mongock doesn't support value currently, but the first approach will require the constructor parameter to have that #Value("${login-secret}"), not at the field level.

Related

#ConfigurationProperties do not seem to work when also injecting a bean

I have the following situation:
#Configuration
#ConfigurationProperties(prefix = "my.prefix")
#ConditionalOnProperty(value = "my.prefix.should-enable", havingValue = "true")
#RequiredArgsConstructor // lombok
public class MyConf {
#Setter
private Map<String, SettingOverride> overrides = Collections.emptyMap();
private final RestTemplate restTemplate;
#Data
public static class SettingOverride {
private final boolean enabled;
}
}
And the following configuration (enabled only for a specific profile via application-profilename.yml):
---
my:
prefix:
should-enable: true
overrides:
SOME_SETTING:
enabled: true
The RestTemplate bean is successfully injected, yet the my overrides Map is always empty. A few days ago when I last tested this code, this approach seemed to work.
Interestingly, I found this bit in the reference documentation:
We recommend that #ConfigurationProperties only deal with the environment and, in particular, does not inject other beans from the context. For corner cases, setter injection can be used or any of the *Aware interfaces provided by the framework (such as EnvironmentAware if you need access to the Environment). If you still want to inject other beans using the constructor, the configuration properties bean must be annotated with #Component and use JavaBean-based property binding.
which makes me think that this approach should never have worked (I'm unable to figure out why it even worked, as alternative approaches to the above have all failed).
Trying to make my #Configuration class inject the RestTemplate via e.g. ApplicationContextAware and a default constructor, as suggested in the above documentation, does not work either.
Since this is a test configuration class, it would be ideal if all corresponding properties and structures would be in a single class.
A different configuration class which uses other properties, e.g. (note: no injected beans) :
#Data // lombok
#Configuration
#ConditionalOnProperty(value = "my.other-prefix.should-enable", havingValue = "true")
#ConfigurationProperties(prefix = "my.other-prefix")
public class MyOtherConf {
private String someValue;
private Map<String, String> settings = Collections.emptyMap();
}
with a config of:
---
my:
other-prefix:
should-enable: true
settings:
another-value: "anothervalue"
seems to work without issues. What am I doing wrong?

ConfigProperty not injecting the value into the field

I am new to quarkus environment. I have a quarkus application where I'm trying to inject the property config using
org.eclipse.microprofile.config.inject.ConfigProperty
Here is the sample code
public class Temp {
#ConfigProperty(name = "secret.token")
static String SECRET_KEY;
public void display() {
System.out.println(SECRET_KEY);
}
}
Here is the content of my application.properties
secret.token = ${TOKEN_SECRET:Root}
Here display method is always printing null.
The thing is the same property is being injected into the controller/resource endpoint classes properly but not in this class. I also tried using #Inject along with #ConfigProperty but no luck. Any pointers would really help.
The class on which the annotation is used, needs to be a CDI bean.
The easiest way to accomplish that is to annotate the class with #Singleton and use with something like #Inject Temp temp wherever the class is used.
See https://quarkus.io/guides/cdi for an intro to CDI

What's the Spring way of accessing properties from an entity?

I'm new to Spring and I'm building an application where some entities (JPA/Hibernate) need access to a property from application.properties. I do have a configuration class in which this is trivial:
#Configuration
public class FactoryBeanAppConfig {
#Value("${aws.accessKeyId}")
private String awsAccessKeyId;
#Value("${aws.secretKey}")
private String awsSecretKey;
}
but since entities do not have and I think they should not have the annotations such as #Configuration or #Component, what's the Spring way for them to access the property?
Now, I know I can create my own class, my own bean, and make it as a simple wrapper around the properties; but is that the Spring way to do it or is there another way?
specify Property file location using #PropertySource
Something like below
#PropertySource("classpath:/application.proerties")
You also need to add below bean in your config
#Bean
public static PropertySourcesPlaceholderConfigurer propertyConfigIn() {
return new PropertySourcesPlaceholderConfigurer();
}
There is no "Spring way", since JPA entities and Spring have nothing to do with each other. Most importantly, JPA entities are not Spring beans, so Spring doesn't know or care about them as they're not managed by Spring.
You can try to hack around, trying in vain to access Spring's configuration from code that should not be trying to access it, or you can accept the truth that your design is broken and you're trying to do something that's not meant to be done.
As was proposed several times, use a service class for this. It's managed by Spring, so it can access the Spring config, and it can handle entities, so there's no crossing boundaries.
First create a public static variable in some bean managed by Spring, then make the following use of the #Value annotation.
public static String variable;
#Value("${variable}")
private void setVariable(String value) {
variable = value;
}
It will be set at runtime on startup, now you can access it from entities and everywhere else because it is just a public static var.
You can use #PropertySource to load the properties file as follows
#Configuration
#PropertySource("classpath:/com/organization/config/application.proerties")
public class FactoryBeanAppConfig {
...
}
Entities should not acces environment properties. If you are using your entity through a service, then the service can access the properties to act on the entity.

Spring dependency injection via setter method and Configuration class

I wanna switch from xml based spring configuration into java-based. For constructor type injection it is easy. Example I am using:
#Configuration
public class BeanConfiguration {
#Bean
public GreetingService greetingService(GreetingDao greetingDao) {
return new GreetingService(greetingDao);
}
#Bean
public GreetingDao greetingDao() {
return new GreetingDao();
}
}
However, when I want to inject through setter method I am doing something like this:
#Configuration
public class BeanConfiguration {
#Bean
public MeetingDao meetingDao() {
return new MeetingDao();
}
#Bean
public MeetingService meetingService(MeetingDao meetingDao) {
MeetingService meetingService = new MeetingService();
meetingService.setMeetingDao(meetingDao);
return meetingService;
}
}
I am not sure if this is a possible way to inject with Java-based Configuration and setter method. Unfortunately I cannot find any example (for constructor dependencies a lot of examples exists). Also I am not sure in case of Java-based configuration when should I use constructor and when setter. In Spring docs it is described that I should use constructor for required and setter for optional dependency. However, I see it as the same result for this kind of approach.
Thanks for any clarification.
Adam
Under the assumption that you cannot change the classes themselves, you could always just not return the bean until you have injected all the values.
#Configuration
public class YourConfig{
#Value("${some.value.from.properties}")
private String someValue;
#Bean
#Autowired
public YourBean yourBean(TheDependency theDependency){
YourBean bean = new YourBean();
bean.setTheDependency(theDependency);
bean.setSomeValue(someValue);
return bean;
}
}
Constructor injection is always preferred with class dependencies, but not always possible.
If you have access to changing the source for these services and beans you are creating, then I suggest using constructor injection and placing "#Service" on the class and "#Autowired" on the constructors.
Properties are an example of "optional" dependencies; it is common to default values and behavior if not provided. I prefer just placing the "#Value" directly on that field instead of my constructor because otherwise you might end up with WAY too many parameters. This is "setter" injection, but you don't want an actual setter method (again, not normally anyways); you only want Spring to change the value, not any of your other code.
Using "#Value" is fine if you only have one or two properties(or 3? It's not an exact science); however, if you find you have a lot of fields with "#Value" then you should use a configuration bean instead. An "#ConfigurationProperties" bean can also be treated the same way with "setter" injection, but I prefer constructor injection to be sure that at least the bean is never null, even though it's values might be.

Spring - creating objects with new operator using #Configurable & #Value annotations

Is it possible to use #Configurable on a class that's weaved using AspectJ and get Spring to load in values on fields/methods which are annotated with #Value?
I know its possible with #Autowired and #Resource etc... Are there any others.
e.g.
#Configurable
public Class MyObj{
#Value("$(my.prop)")
private String aField;
public String getAField(){
return aField;
}
}
And then have something like
public aMethodSomewhereElse(){
MyObj obj = new MyObj()
assertNotNull(obj.getAField());
}
Are there any alternatives to being able to create MyObj with the new operator and still get spring to handle the annotations?
--EDIT:--
It IS possible to do this using new when using #Autowired, have a look at some Hibernate and JPA stuff with Spring and AOP... I've used this in the past to do some profiling of Java code. But I really want to use SPEL and #Value before I mock up a full example I was hoping to find the answer here. FYI - if you don't belive me the Spring Manual even says it is possible to do this, what I want to know is if its possible to use #Value annotations in the same scope...
The Spring container instantiates and configures beans defined in your
application context. It is also possible to ask a bean factory to
configure a pre-existing object given the name of a bean definition
containing the configuration to be applied. The spring-aspects.jar
contains an annotation-driven aspect that exploits this capability to
allow dependency injection of any object.
And...
Using the annotation on its own does nothing of course. It is the
AnnotationBeanConfigurerAspect in spring-aspects.jar that acts on the
presence of the annotation. In essence the aspect says "after
returning from the initialization of a new object of a type annotated
with #Configurable, configure the newly created object using Spring in
accordance with the properties of the annotation". In this context,
initialization refers to newly instantiated objects (e.g., objects
instantiated with the 'new' operator) as well as to Serializable
objects that are undergoing deserialization (e.g., via readResolve()).
http://static.springsource.org/spring/docs/3.0.0.RC2/reference/html/ch07s08.html
Cheers.
You are absolutely right - #Autowired fields will be wired in an #Configurable annotated class even outside of a Spring container, assuming that you have a AspectJ infrastructure in place.
You have noted a good catch though, #Value fields are processed by a Spring bean post processor(AutowiredAnnotationBeanPostProcessor), which resolves the #Value annotated fields. It does not act on objects instantiated outside of the container though - so in short, the #Autowired fields should get wired in, but #Value properties will not.
Doing
MyObj obj = new MyObj()
means that obj is not managed by spring, so it will not do autowiring.
Only way to do that is to obtain instance from an application context. For example:
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
MyObj obj = context.getBean("myBean");
I don't think it is possible to use new operator and ask spring to autowire properties. I think 1 way to solve this is to get a static reference to applicationContext and create a prototype scoped bean.
#Component
public class ApplicationContextLocator {
private static ApplicationContext applicationContext;
public static ApplicationContext getApplicationContext() {
return applicationContext;
}
public ApplicationContextLocator() {
super();
}
#Autowired
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
ApplicationContextLocator.applicationContext = applicationContext;
}
}
#Scope(BeanDefinition.SCOPE_PROTOTYPE)
#Component
public class MyObj {
.....
}
public aMethodSomewhereElse(){
MyObj obj = ApplicationContextLocator.getApplicationContext().getBean(MyObj.class)
assertNotNull(obj.getAField());
}

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