@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.

What is the difference between @component and @configuration?

The main difference between these annotations is that @ComponentScan scans for Spring components while @EnableAutoConfiguration is used for auto-configuring beans present in the classpath in Spring Boot applications.

What is used to configure as Java?

You can automatically configure your system directly after the installation using the functional unit configuration tool, which makes the technical settings for Java functional units. …

What is Spring configuration class?

Spring @Configuration annotation is part of the spring core framework. Spring Configuration annotation indicates that the class has @Bean definition methods. So Spring container can process the class and generate Spring Beans to be used in the application.

What is the use of @SpringBootApplication?

Spring Boot @SpringBootApplication annotation is used to mark a configuration class that declares one or more @Bean methods and also triggers auto-configuration and component scanning. It’s same as declaring a class with @Configuration, @EnableAutoConfiguration and @ComponentScan annotations.

What is @component and @service?

@Component is a generic stereotype for any Spring-managed component. @Service annotates classes at the service layer. @Repository annotates classes at the persistence layer, which will act as a database repository.

How read config file in Java?

1. Create a java class named ReadPropertyFile. java inside the same project where config. properties file is created → include “public static main” method and Finish.
2. First we have to create object of Properties class.

Can we replace @controller with @component?

They are nothing but the specialized form of @Component annotation for certain situations. … Even if you replace @Controller annotation with @Compoenent, Spring can automatically detect and register the controller class but it may not work as you expect with respect to request mapping.

What is the difference between @component and @service?

@Component : It is a basic auto component scan annotation, it indicates annotated class is an auto scan component. @Controller : Annotated class indicates that it is a controller component, and mainly used at the presentation layer. @Service : It indicates annotated class is a Service component in the business layer.

What is the use of configure?

To configure is to set something up, arrange something in a particular way, or fix something up for a particular purpose. When you set up all of your computer preferences to work for you, this is an example of when you configure your computer.

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How does Spring achieve DI or IoC?

The Spring container uses Dependency Injection (DI) to manage the components that build up an application and these objects are called Spring Beans. Spring implements DI by either an XML configuration file or annotations. … IoC is also known as dependency injection (DI).

What is @configuration and @bean in Spring?

Annotating a class with the @Configuration indicates that the class can be used by the Spring IoC container as a source of bean definitions. The @Bean annotation tells Spring that a method annotated with @Bean will return an object that should be registered as a bean in the Spring application context.

What is difference between Java based configuration and annotation based configuration?

They are similar, but have subtle differences. Instead of having an @Component annotation on your class( which is annotation-based configuration ), you can skip the @Component and instead have a @Bean annotated method which returns a new instance of this class. ( this is Java-based configuration).

What is Spring boot configuration?

@Configuration is an analog for xml file. Such classes are sources of bean definitions by defining methods with the @Bean annotation. @Configuration is: not required, if you already pass the annotated class in the sources parameter when calling the SpringApplication.

What is @component annotation in Spring?

@Component is an annotation that allows Spring to automatically detect our custom beans. In other words, without having to write any explicit code, Spring will: Scan our application for classes annotated with @Component. Instantiate them and inject any specified dependencies into them.

What is the difference between @RestController and @controller?

The @Controller annotation indicates that the class is a “Controller” e.g. a web controller while the @RestController annotation indicates that the class is a controller where @RequestMapping methods assume @ResponseBody semantics by default i.e. servicing REST API.

What does SpringApplication run call?

SpringApplication. run(Classname. class, args) bootstraps a spring application as a stand-alone application from the main method. It creates an appropriate ApplicationContext instance and load beans.

What is the difference between @SpringBootApplication and @EnableAutoConfiguration annotation?

@SpringBootApplication is a newer version of @EnableAutoConfiguration which was introduced in Spring Boot 1.2. @ComponentScan enables component scanning so that web controller classes and other components that you create will be automatically discovered and registered as beans in spring’s application context.

Where is Java configuration file?

All configured options are stored in the . drjava file in the user’s home directory. (The location of this file varies on different platforms.) This file is a standard Java properties file, with one option on each line and with option keys and values separated by an equals sign.

What is Property class Java?

Properties is a subclass of Hashtable. It is used to maintain a list of values in which the key is a string and the value is also a string i.e; it can be used to store and retrieve string type data from the properties file. Properties class can specify other properties list as it’s the default.

How create .properties file in Java?

1. Create a new file from file menu Or press Ctrl + N.
2. In place of file name write config.properties then click finish.

What is @service and @repository?

The repository is where the data is stored. The service is what manipulates the data. In a real-world situation comparison, if your money is stored in a vault in a bank, the vault is the repository. The teller that deposits, withdraws, etc is the service.

What is the difference between @component and @repository?

The difference between them is, @component is used to annotate compound classes, @Repository is a marker for automatic exception translation in the persistence layer, for service layer we need to use @service. You can refer Spring Documentation to know more.

What is difference between @component and @bean?

@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 will happen if you will use @service over a DAO?

In your scenario, it has no impact on application flow whether you use @Service or @Repository, application will work as they are elligible for autowiring. But standard practice is to use @Repository for dao classes.

What is the @service annotation?

@Service annotation is used in your service layer and annotates classes that perform service tasks, often you don’t use it but in many case you use this annotation to represent a best practice. For example, you could directly call a DAO class to persist an object to your database but this is horrible.

Why @service is used in spring?

Spring @Service annotation is used with classes that provide some business functionalities. Spring context will autodetect these classes when annotation-based configuration and classpath scanning is used.

What is a configuration example?

The definition of configuration is the way parts are arranged to work together. … When you try to set up your computer hardware and software to work the way you want such as adding a wireless mouse and keyboard, this is an example of configuration.

What is the difference between installation and configuration?

Installation or setup is the act of making the system or program ready for execution. … The configuration affects system function and performance.

What is IP configuration?

The IP Configuration window configures the Internet Protocol parameters, allowing the device to receive and send IP packets. You can use the web browser interface to access IP addressing only if the switch already has an IP address that is reachable through your network. …

What is Inversion of Control Java?

Inversion of Control (IoC) means to create instances of dependencies first and latter instance of a class (optionally injecting them through constructor), instead of creating an instance of the class first and then the class instance creating instances of dependencies.