Spring MVC体系结构和处理请求控制器-EW帮帮网

1. Spring MVC是什么

环境搭建⭐：

导入依赖：

    <!--spring-mvc-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>${spring.version}</version>
    </dependency>

    <!--文件上传-->
    <dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.3.1</version>
    </dependency>
    <dependency>
      <groupId>commons-io</groupId>
      <artifactId>commons-io</artifactId>
      <version>2.4</version>
    </dependency>
    <dependency>
      <groupId>commons-fileupload</groupId>
      <artifactId>commons-fileupload</artifactId>
      <version>1.3.1</version>
    </dependency>
    <dependency>
      <groupId>commons-io</groupId>
      <artifactId>commons-io</artifactId>
      <version>2.4</version>
    </dependency>

    <!--json-->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.2.33</version>
    </dependency>

配置spring-mvc文件：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/mvc
       http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!--控制器mvc路径，启动注解-->
    <context:component-scan base-package="com.zb.controller"/>

    <!--设置字符串编码-->
    <mvc:annotation-driven>
        <mvc:message-converters>
            <bean class="com.alibaba.fastjson.support.spring.FastJsonHttpMessageConverter">
                <property name="supportedMediaTypes">
                    <list>
                        <value>text/html;charset=UTF-8</value>
                        <value>application/json;charset=UTF-8</value>
                    </list>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>


    <!--&lt;!&ndash;上传文件的配置内容&ndash;&gt;-->
    <!--<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">-->
        <!--<property name="defaultEncoding" value="UTF-8"></property>-->
        <!--<property name="maxUploadSize" value="10485760"></property>-->
    <!--</bean>-->

</beans>

配置web. xml文件：

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.4"
         xmlns="http://java.sun.com/xml/ns/j2ee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee
        http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">


  <!--解决跨域问题-->
  <filter>
    <filter-name>corsFilter</filter-name>
    <filter-class>com.zb.filters.CorsFilters</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>corsFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>


  <!--解决字符编码问题-->
  <filter>
    <filter-name>myEncodeing</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <init-param>
      <param-name>encoding</param-name>
      <param-value>UTF-8</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>myEncodeing</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>


  <!--servlet将经由spring-mvc处理-->
  <servlet>
    <servlet-name>dispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>
        classpath:spring-mvc.xml;
        classpath:spring-mybatis.xml
      </param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>dispatcherServlet</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>
</web-app>

创建controller

2. 注解驱动控制器

3. Spring MVC请求处理流程

4. Spring MVC体系结构

5. 参数传递⭐

在 Spring 框架中，@RestController 是一个组合注解，用于标识一个类作为 RESTful 风格的控制器。它结合了 @Controller 和 @ResponseBody 的功能，意味着该控制器中的所有方法默认都会将返回值直接写入 HTTP 响应体中，而不是通过视图解析器渲染视图。是最常用的控制器风格。

spring-mvc有四种不同的传参方式：