Spring MVC


<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>6.1.0</version>
</dependency>

传统XML配置形式

将DispatcherServlet替换掉Tomcat自带的Servlet,并为Web程序配置一个Spring上下文环境


<servlet>
    <servlet-name>mvc</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:application.xml</param-value>
    </init-param>
</servlet>
<servlet-mapping>
    <servlet-name>mvc</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

全注解配置方式

Tomcat将会在类路径中查找实现ServletContainerInitializer接口的类，若发现则用来配置Servlet，Spring提供了这个接口的实现类SpringServletContainerInitializer

而SpringServletContainerInitializer将会反过来查找实现WebApplicationInitializer的类，在Spring中AbstractAnnotationConfigDispatcherServletInitializer实现了这个接口，使用注解配置时直接继承既可


public class MainInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {
    @Override
    protected Class<?>[] getRootConfigClasses() {
        return new Class[]{WebConfiguration.class};
    }
 
    @Override
    protected Class<?>[] getServletConfigClasses() {
        return new Class[0];
    }
 
    @Override
    protected String[] getServletMappings() {
        return new String[]{"/"};
    }
}

其中WebConfiguration为Spring的配置类


@Configuration
@EnableWebMvc // 快速配置SpringMVC
@ComponentScan("com.controller")
public class WebConfiguration {
}