I have a Spring application (not Spring Boot) with xml configuration.
To read properties from application.yml in Spring Boot I would use #EnableConfigurationProperties annotation to enable the functionality and then I would use #ConfigurationProperties on my class.
Is there somethis like this in pure Spring? Now it's done with #Value annotations
#Component
#Getter
#RequiredArgsConstructor
public class TestProperties2 {
#Value("${myprop}")
private String myProp;
#Value("${commonprop}")
private String commonprop;
}
Related
I am configuring the shiro-spring-starter.
#Configuration
public class ShiroConfig {
#Bean
public Realm realm() {
return new UserRealm();
}
}
\\Without #Component
public class UserRealm extends AuthorizingRealm {
#Autowired
private UserMapper userMapper;
}
UserRealm was create using "new UserRealm()",without #Component.
why the #Autowired work?
In your code, the #Component annotation is not required because you've created the UserRealm object as a spring bean in the ShiroConfig class. Since it's a spring bean, spring will manage the object and perform the dependency injections specified by the #Autowired annotation.
If you didn't create the UserRealm object as a spring bean in the ShiroConfig class, you would then need the #Component annotation on the UserRealm class. The #Component annotation would cause spring to automatically create an instance of the UserRealm class as a spring bean, assuming component scanning is enabled.
So you either don't use a #Component annotation and manually create spring beans in your configuration class, or use the #Component annotation and let spring automatically create the spring bean. The result is the same.
My spring Boot application uses a class annotated with #Configuration and #ConfigurationProperties:
#Configuration
#ConfigurationProperties(prefix = "my")
#Getter
#Setter
public class MyConfigurationProperties {
#Value("${timeout}")
private int defaultTimeout;
}
Now I'd like to read and update these configuration properties using a (private) REST interface, so I created the following controller.
#RestController
#RequestMapping(path = "config")
public class ConfigController {
final MyConfigurationProperties myConfig;
public ConfigController(MyConfigurationProperties myConfig) {
this.myConfig = myConfig;
}
#GetMapping(produces = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<MyConfigurationProperties> get() {
return ResponseEntity.ok(myConfig);
}
}
Unfortunately this doesn't seem to work as I get the following exception when calling the endpoint:
com.fasterxml.jackson.databind.exc.InvalidDefinitionException: No serializer found for class org.springframework.context.expression.StandardBeanExpressionResolver and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationFeature.FAIL_ON_EMPTY_BEANS)
The JSON response even contains "strange" properties when disabling FAIL_ON_EMPTY_BEANS:
How would I be able to (de-)serialize this configuration class using Jackson?
When removing the annotations #Configuration and #ConfigurationProperties for testing purposes, the serialization works just fine. So it seems to have to do something with the class being a bean?
You are mixing things: configuration properties and autowiring a value. If you want to have a POJO as a configuration property class, drop the #Value annotation. You can also drop #Configuration annotation if you add #EnableConfigurationProperties to your main class (this way all #ConfigurationProperties classes will be automatically detected). If a problem persists, please update the question and show us how the properties prefixed with 'my' look like.
i have following #CongfigurationProperties class
//#Component
#ConfigurationProperties
#PropertySource("classpath:typesofcharge.properties")
public class ChargeProperties {
private HashMap<String,String> charge=new HashMap<>();
public HashMap<String,String> getCharge()
{
return this.charge;
}
}
And this is my Configuration file
#SpringBootApplication
#ComponentScan({"com.vehiclemanagement.config,com.vehiclemanagement.client,"
+ "com.vehiclemanagement.controller,"
+ "com.vehiclemanagement.exception,"
+ "com.vehiclemanagement.model,"
+ "com.vehiclemanagement.service"})
#EnableConfigurationProperties(ChargeProperties.class)
public class VehicleManagementConfig {
public static void main(String[] args) {
SpringApplication.run(VehicleManagementConfig.class, args);
}
}
If i use #Component annotation in ChargeProperties and remove ChargeProperties.class annotation in Configuration class the charge HashMap is initialized properly
If i remove #Component and pass ChargeProperties.class as argument like this
#EnableConfigurationProperties(ChargeProperties.class) like how document says the charge HashMap is empty when i run
I am using spring boot 2.0.2 release .But i am following latest docs. Can anyone explain why this are not working as document suggest
content of property file is as follows
UPDATE the content of property files are as shown
#DO NOT MODIFY THIS FILE
charge.peak=Double_rate;
charge.lateNight=duration_based_charge;
charge.earlyMorning=special_offers;
When specifying ChargeProperies.class on the #EnableConfigurationProperties annotation it will be registered as a bean through the EnableConfigurationPropertiesImportSelector class inside #EnableConfigurationProperties.
So in the example, if you have only annotated the ChargeProperties class with #ConfigurationProperties it will create a chargeProperties bean with an empty charge HashMap because it defaulted back to application.properties as the source.
A custom source can be specified by using #PropertySource.
#PropertySource annotation providing a convenient and declarative mechanism for adding
a PropertySource to Spring's Environment. To be used in conjunction
with #Configuration classes.
As per documentation above, to use #PropertySource to load the custom source, one has to use the #Configuration annotation.
#Configuration
#PropertySource("classpath:typesofcharge.properties")
Under the hood a #Configuration class is a #Component.
#Target(value=TYPE)
#Retention(value=RUNTIME)
#Documented
#Component
public #interface Configuration
So to your question. By specifying a custom #PropertySource without #Configuration, spring did not load the properties in the #PropertySource annotation and defaulted back to the application.properties.
If we use #PropertySource we have to use component otherwise the properties will not be read
since we added the #ComponentScan We don't have to mention #EnableConfiguationProperties annotation at all The propety class object can be autowired as Bean
Spring only autowires beans to fields/setters/constructors which are annotated with #Resource, #Autowired (not considering Java Config and XML configuration).
Is there a way to configure Spring to automatically guess where the #Resource/ #Autowired annotations could be placed and do the autowiring based on that?
Here's how it works in Grails:
class BookController {
def bookService
…
}
How can I make it working in Spring?
#Controller
public class BookController {
BookService bookService
…
}
I have this HTTP listener subclass
public class MigificSessionListener implements HttpSessionListener {
#Autowired
#Qualifier("notificationThread")
private NotificationThread notificationThread;
#Override
public void sessionDestroyed(HttpSessionEvent hse) {
// here notificationThread value is null
}
}
Value of notificationThread inside sessionDestroyed() is null.
How can i autowire sessionDestroyed inside this class ?
Your MigificSessionListener in not in your spring conext, spring even do not know it exists.
You can use WebApplicationContextUtils to get your spring context from ServletContext
WebApplicationContextUtils.getWebApplicationContext(sessionEvent.getSession().getServletContext())
You can enable Spring AOP with #EnableSpringConfigured and annotate your class with #Configurable. This let spring manage instances which are created outside the spring context with new. You will also need to enable either load-time weaving or compile-time weaving. This is documented in 9.8.1 Using AspectJ to dependency inject domain objects with Spring.
#Configuration
#EnableSpringConfigured
public class AppConfig {
}
#Configurable
public class MigificSessionListener implements HttpSessionListener {
#Autowired
#Qualifier("notificationThread")
private NotificationThread notificationThread;
//...
}
Convert your non-Spring managed class MigificSessionListener into a Spring-managed one by annotating it with #Configurable.
For this annotation to be recognised you need <context:spring-configured/> in your Spring XML config or #EnableSpringConfigured if you are using Spring Java config.
The #Autowired or injection of other dependencies will then succeed.