What is controller in spring?

Asked By: Jakes Kordesee | Last Updated: 20th January, 2020
Category: technology and computing programming languages
4.3/5 (310 Views . 34 Votes)
Controller - A controller contains the business logic of an application. Here, the @Controller annotation is used to mark the class as the controller. Front Controller - In Spring Web MVC, the DispatcherServlet class works as the front controller. It is responsible to manage the flow of the Spring MVC application.

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Also, what is rest controller in spring?

Spring RestController annotation is a convenience annotation that is itself annotated with @Controller and @ResponseBody . Spring RestController annotation is used to create RESTful web services using Spring MVC. Spring RestController takes care of mapping request data to the defined request handler method.

Also, what is the use of controller in Spring MVC? Typically, in Spring MVC, we write a controller class to handle requests coming from the client. Then, the controller invokes a business class to process business-related tasks, and then redirects the client to a logical view name, which is resolved by Spring's dispatcher servlet in order to render results or output.

Correspondingly, what are the types of controller in spring?

Here is the list of anstract controllers that comes with the Spring MVC module:

  • SimpleFormController.
  • AbstractController.
  • AbstractCommandController.
  • CancellableFormController.
  • AbstractCommandController.
  • MultiActionController.
  • ParameterizableViewController.
  • ServletForwardingController.

What is difference between controller and rest controller in spring?

Difference between @RestController and @Controller in Spring. The @Controller is a common annotation which is used to mark a class as Spring MVC Controller while @RestController is a special controller used in RESTFul web services and the equivalent of @Controller + @ResponseBody.

39 Related Question Answers Found

What is the difference between spring 4 and 5?

So Spring 4 had to support Java 6, 7 and 8. To maintain the backward compatibility, Spring framework didn't adapted many new features which Java 8 brought with itself e.g. Lambda programming. Spring 5 has baseline version 8, so it uses many new features of Java 8 and 9 as well.

What is Autowired?

Advertisements. The @Autowired annotation provides more fine-grained control over where and how autowiring should be accomplished. The @Autowired annotation can be used to autowire bean on the setter method just like @Required annotation, constructor, a property or methods with arbitrary names and/or multiple arguments

What is @RequestBody?

@RequestBody. This is used to convert the body of the HTTP request to the java class object with the aid of selected HTTP message converter. This annotation will be used in the method parameter and the body of the http request will be mapped to that method parameter.

What is spring Autowiring?

Autowiring in Spring. Autowiring feature of spring framework enables you to inject the object dependency implicitly. It internally uses setter or constructor injection. Autowiring can't be used to inject primitive and string values. It works with reference only.

What are spring annotations?

Spring Annotations. Spring framework implements and promotes the principle of control inversion (IOC) or dependency injection (DI) and is in fact an IOC container. Traditionally, Spring allows a developer to manage bean dependencies by using XML-based configuration. That's why Spring annotations were introduced.

What is @RequestBody in spring?

Simply put, the @RequestBody annotation maps the HttpRequest body to a transfer or domain object, enabling automatic deserialization of the inbound HttpRequest body onto a Java object. This is all that is needed for a Spring REST API and an Angular client using the @RequestBody annotation!

What is @controller annotation in spring?

@Controller annotation is an annotation used in Spring MVC framework (the component of Spring Framework used to implement Web Application). The @Controller annotation indicates that a particular class serves the role of a controller.

How does Spring controller work?

Spring MVC is request driven and DispatcherServlet handles the request from client and then dispatches the request to controllers. It tightly integrates with the Spring IoC container and allows the developers to use every features of Spring framework.

What is @RequestMapping?

@RequestMapping is one of the most widely used Spring MVC annotation. org. RequestMapping annotation is used to map web requests onto specific handler classes and/or handler methods. @RequestMapping can be applied to the controller class as well as methods.

What is Dao in spring?

It's a design pattern in which a data access object (DAO) is an object that provides an abstract interface to some type of database or other persistence mechanisms. Spring data access framework is provided to integrate with different persistence frameworks like JDBC, Hibernate, JPA, iBatis etc.

How do you call multiple controllers in spring?

Spring MVC Multiple Controller Example
  1. Load the spring jar files or add dependencies in the case of Maven.
  2. Create the controller class.
  3. Provide the entry of controller in the web. xml file.
  4. Define the bean in the separate XML file.
  5. Create the other view components.
  6. Start the server and deploy the project.

What is @component annotation in spring?

Spring Component annotation is used to denote a class as Component. It means that Spring framework will autodetect these classes for dependency injection when annotation-based configuration and classpath scanning is used.

How does Spring Boot define controller?

Spring Boot @Controller. @Controller annotation indicates that the annotated class is a controller. It is a specialization of @Component and is autodetected through classpath scanning. It is typically used in combination with annotated handler methods based on the @RequestMapping annotation.

Can we Autowire HttpServletRequest?

It is possible to autowire HttpServletRequest also into non request-scoped beans, because for HttpServletRequest Spring will generate a proxy HttpServletRequest which is aware how to get the actual instance of request. So it is safe to autowire request even if your controller is singleton scoped.

What is front controller in spring?

What is the front controller class of Spring MVC? A front controller is defined as a controller that handles all requests for a Web Application. DispatcherServlet servlet is the front controller in Spring MVC that intercepts every request and then dispatches requests to an appropriate controller.

How do you Autowire annotation in spring?

In most cases, you may need autowired property in a particular bean only. In Spring, you can use @Autowired annotation to auto wire bean on the setter method, constructor or a field. Moreover, it can autowired property in a particular bean. The @Autowired annotation is auto wire the bean by matching data type.

What is the difference between struts and spring?

The major difference between Spring MVC and Struts is: Spring MVC is loosely coupled framework whereas Struts is tightly coupled. For enterprise Application you need to build your application as loosely coupled as it would make your application more reusable and robust as well as distributed.