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What is configuration class?
@Configuration annotation 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. This is called Spring Java Config feature (using @Configuration annotation).
Can configuration class be Autowired?
In addition to being able to reference any particular bean definition as seen above, one @Configuration class may reference the instance of any other @Configuration class using @Autowired . This works because the @Configuration classes themselves are instantiated and managed as individual Spring beans.
What are the classes in spring boot?
A Spring Boot application’s main class is a class that contains a public static void main() method that starts up the Spring ApplicationContext. By default, if the main class isn’t explicitly specified, Spring will search for one in the classpath at compile time and fail to start if none or multiple of them are found.
Can we Autowire POJO class?
The @Autowired annotation in spring automatically injects the dependent beans into the associated references of a POJO class. Developers can apply the @Autowired annotation to the following: @Autowired on property. @Autowired on the setter method.
What is the difference between @RestController and @controller?
Difference between @Controller and @RestController in Spring MVC/BOOT. The @Controller is a annotation to mark class as Controller Class in Spring While @RestController is used in REST Web services and similar to @Controller and @ResponseBody.
What is @transactional in spring boot?
The @Transactional annotation is the metadata that specifies the semantics of the transactions on a method. We have two ways to rollback a transaction: declarative and programmatic. In the declarative approach, we annotate the methods with the @Transactional annotation.
What is difference between @bean and @configuration?
@Component is a class level annotation whereas @Bean is a method level annotation and name of the method serves as the bean name. @Component need not to be used with the @Configuration annotation where as @Bean annotation has to be used within the class which is annotated with @Configuration.
What are the functions of the configurationmanager class?
The ConfigurationManager class includes members that enable you to perform the following tasks: Read a section from a configuration file. To access configuration information, call the GetSection method. Read and write configuration files as a whole.
How are configuration settings stored in a class?
Remarks. Configuration settings are stored in a hierarchy of configuration files. The Configuration class instance represents the merged view of the configuration settings from all of the configuration files that apply to a specific physical entity, such as a computer, or to a logical entity, such as an application or a Web site.
How to reference beans across different @ configuration classes?
Fully-qualified bean references with @Autowired In addition to being able to reference any particular bean definition as seen above, one @Configuration class may reference the instance of any other @Configuration class using @Autowired. This works because the @Configuration classes themselves are instantiated and managed as individual Spring beans.
When to use @ configuration classes in Java?
With XMLs you can define dependencies based on classes that are not available during compile time but are provided during run-time. With @Configuration classes you must have the classes available at compile time. Usually that’s not an issue, but there are cases it may be.