introduction
Spring Boot is a fast and simple development framework that can help us quickly build a Spring-based web application. In Spring Boot, we can use WebMvc to build web applications. WebMvc is a module in the Spring framework. It provides support for MVC mode, including controller, view parser, interceptor and other functions. In this article, we will explain how to use WebMvc in Spring Boot.
Create Spring Boot Web Application
First, we need to create a Spring Boot Web application. You can use Spring Initializr to quickly create a Spring Boot project. When creating a project, select Web dependencies as shown in the following figure:
After creating the project, we can see the web dependencies of Spring Boot in the file:
<dependency>
<groupId></groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>Create a controller
In Spring Boot, we can use the @Controller annotation to create a controller. The controller is the core component that handles requests and responses. Here is a simple controller:
@Controller
public class HelloController {
@RequestMapping("/hello")
@ResponseBody
public String hello() {
return "Hello, world!";
}
}In the above code, we use the @Controller annotation to identify that this class is a controller. Use the @RequestMapping annotation to specify the request path and request method to be processed. Use the @ResponseBody annotation to specify the returned content type.
View parser
In Spring Boot, we can use the view parser to parse views. The view resolver resolves the logical view name to the URL of the actual view. Spring Boot uses Thymeleaf as the view resolver by default. Here is a simple Thymeleaf template:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Example</title>
</head>
<body>
<h1 th:text="${message}"></h1>
</body>
</html>In the above code, we use Thymeleaf syntax to set the view content. Use the th:text property to set the text content. In the controller, we can use ModelAndView to set the model data and view names:
@Controller
public class HelloController {
@RequestMapping("/hello")
public ModelAndView hello() {
ModelAndView modelAndView = new ModelAndView("hello");
("message", "Hello, world!");
return modelAndView;
}
}In the above code, we use ModelAndView to set the model data and view names. The view name is "hello", which corresponds to the Thymeleaf template above.
Interceptor
In Spring Boot, we can use an interceptor to intercept requests and process them. Interceptors can be used to implement functions such as logging, security authentication, and performance monitoring. Here is a simple interceptor:
@Component
public class LoggerInterceptor implements HandlerInterceptor {
@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
("Request URL: " + ());
return true;
}
@Override
public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
("Response Status: " + ());
}
}In the above code, we create a LoggerInterceptor class and implement the HandlerInterceptor interface. In the preHandle method, we print the requested URL. In the postHandle method, we print the status code of the response.
In Spring Boot, we need to register the interceptor into WebMvcConfigurer:
@Configuration
public class WebConfig implements WebMvcConfigurer {
@Autowired
private LoggerInterceptor loggerInterceptor;
@Override
public void addInterceptors(InterceptorRegistry registry) {
(loggerInterceptor);
}
}In the above code, we created a WebConfig class and implemented the WebMvcConfigurer interface. In the addInterceptors method, we register the LoggerInterceptor to the interceptor list.
Summarize
In this article, we describe how to use WebMvc in Spring Boot. We created a controller to process requests and responses, used a view parser to parse views, and used an interceptor to intercept requests and process them. Spring Boot's WebMvc module provides us with convenient MVC mode support, allowing us to quickly build web applications.
This is the end of this article about how to use WebMvc in SpringBoot. For more related SpringBoot WebMvc content, please search for my previous articles or continue browsing the related articles below. I hope everyone will support me in the future!