在idea中SpringMVC的配置

MVC是model模型、view视图、controller控制器的简写，是一种软件设计规范。

是将业务逻辑、代码、显示分离的方法来组织代码。

为了降低视图与业务逻辑之间的双向耦合

是一种架构模式

模型（model）业务逻辑、保存数据的状态

视图（view） 显示页面

控制器 controller 取得表单数据 调用业务逻辑 转向指定的页面

pom.xml

    <!--    springmvc-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>5.2.0.RELEASE</version>
    </dependency>

    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>5.2.0.RELEASE</version>
    </dependency>

    <dependency>
      <groupId>ch.qos.logback</groupId>
      <artifactId>logback-classic</artifactId>
      <version>1.3.0-alpha10</version>
    </dependency>

    <dependency>
      <groupId>org.thymeleaf</groupId>
      <artifactId>thymeleaf-spring5</artifactId>
      <version>3.0.12.RELEASE</version>
    </dependency>

    <dependency>
      <groupId>jakarta.servlet</groupId>
      <artifactId>jakarta.servlet-api</artifactId>
      <version>5.0.0</version>
    </dependency>

    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>servlet-api</artifactId>
      <version>2.5</version>
    </dependency>

    <dependency>
      <groupId>jstl</groupId>
      <artifactId>jstl</artifactId>
      <version>1.2</version>
    </dependency>


    <!--jackson依赖-->
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-core</artifactId>
      <version>2.9.5</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.9.5</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-annotations</artifactId>
      <version>2.9.5</version>
    </dependency>
    <dependency>
      <groupId>com.fasterxml.jackson.module</groupId>
      <artifactId>jackson-module-jaxb-annotations</artifactId>
      <version>2.9.5</version>
    </dependency>

<!--    fastjson-->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>fastjson</artifactId>
      <version>1.2.79</version>
    </dependency>

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0">


  <!--配置编码过滤器-->
  <filter>
    <filter-name>CharacterEncodingFilter</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>
    <init-param>
      <param-name>forceResponseEncoding</param-name>
      <param-value>true</param-value>
    </init-param>
  </filter>


  <filter-mapping>
    <filter-name>CharacterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

  <!--配置处理请求方式put和delete的HiddenHttpMethodFilter-->
  <filter>
    <filter-name>HiddenHttpMethodFilter</filter-name>
    <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
  </filter>
  <filter-mapping>
    <filter-name>HiddenHttpMethodFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

  <!--配置SpringMVC的前端控制器DispatcherServlet-->
  <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:springmvc.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>

springmvc.xml

<?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:p="http://www.springframework.org/schema/p"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop"
       xmlns:tx="http://www.springframework.org/schema/tx"
       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/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx.xsd
         http://www.springframework.org/schema/mvc
          http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!--扫描组件-->
    <context:component-scan base-package="com.controller.controller"></context:component-scan>

    <!--配置Thymeleaf视图解析器-->
    <bean id="viewResolver" class="org.thymeleaf.spring5.view.ThymeleafViewResolver">
        <property name="order" value="1"/>
        <property name="characterEncoding" value="UTF-8"/>
        <property name="templateEngine">
            <bean class="org.thymeleaf.spring5.SpringTemplateEngine">
                <property name="templateResolver">
                    <bean class="org.thymeleaf.spring5.templateresolver.SpringResourceTemplateResolver">

                        <!-- 视图前缀 -->
                        <property name="prefix" value="/WEB-INF/templates/"/>

                        <!-- 视图后缀 -->
                        <property name="suffix" value=".html"/>
                        <property name="templateMode" value="HTML5"/>
                        <property name="characterEncoding" value="UTF-8" />
                    </bean>
                </property>
            </bean>
        </property>
    </bean>

    <!--配置视图控制器-->
    <mvc:view-controller path="/" view-name="index"></mvc:view-controller>


    <!--开启mvc注解驱动-->
    <mvc:annotation-driven />


    <!--    让springmvc 不处理静态资源-->
    <mvc:default-servlet-handler/>


<!--    JSON乱码解决-->
    <!--JSON乱码配置-->
    <mvc:annotation-driven>
        <mvc:message-converters register-defaults="true">
            <bean class="org.springframework.http.converter.StringHttpMessageConverter">
                <constructor-arg value="UTF-8"/>
            </bean>
            <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter">
                <property name="objectMapper">
                    <bean class="org.springframework.http.converter.json.Jackson2ObjectMapperFactoryBean">
                        <property name="failOnEmptyBeans" value="false"/>
                    </bean>
                </property>
            </bean>
        </mvc:message-converters>
    </mvc:annotation-driven>

</beans>

JSON工具类

    //自定义时间格式
    public static String getJson(Object object,String dateformat){
        ObjectMapper objectMapper = new ObjectMapper();

        //不使用时间戳的方式
        objectMapper.configure(SerializationFeature.WRITE_DATE_KEYS_AS_TIMESTAMPS,false);
        //自定义日期的格式
        SimpleDateFormat sdf = new SimpleDateFormat(dateformat);

        objectMapper.setDateFormat(sdf);

        try {
            return objectMapper.writeValueAsString(object);
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        return null;
    }

    //常用时间格式
    public static String getJson(Object object){
        return  getJson(object,"yyyy-HH-dd HH:mm:ss");
    }

java对象转换JSON     jackon  fastjson

 @RequestMapping("/j2")
    @ResponseBody//标注后 不会去找视图解析器
    public String json2() throws JsonProcessingException {

        List<User> list = new ArrayList<>();

        User user = new User(11,"小王","111");
        User user1 = new User(11,"小王","111");
        User user2 = new User(11,"小王","111");
        User user3 = new User(11,"小王","111");
        User user4 = new User(11,"小王","111");
        User user5 = new User(11,"小王","111");

        list.add(user);
        list.add(user1);
        list.add(user2);
        list.add(user3);
        list.add(user4);
        list.add(user5);

        //jackon  导入的包
        ObjectMapper mapper = new ObjectMapper();

        String s = mapper.writeValueAsString(list);

        return s;
    }

 @RequestMapping("/j4")
    @ResponseBody//标注后 不会去找视图解析器
    public String json4() throws JsonProcessingException {
        List<User> list = new ArrayList<>();

        User user = new User(11,"小王","111");
        User user1 = new User(11,"小王","111");
        User user2 = new User(11,"小王","111");
        User user3 = new User(11,"小王","111");
        User user4 = new User(11,"小王","111");
        User user5 = new User(11,"小王","111");

        list.add(user);
        list.add(user1);
        list.add(user2);
        list.add(user3);
        list.add(user4);
        list.add(user5);

        //将Java对象转成json字符串
        String s = JSON.toJSONString(list);

        return s;
    }

Controller类

@Controller
public class HelloController {

    @RequestMapping(value = "/index", method = RequestMethod.GET)
    public String getAllEmployee(){
        return "index";
    }
    
    @RequestMapping(value="/hello",method = RequestMethod.GET)
    public String test(){
        return "hello";
    }
}