MVC概念

model（模型）：数据模型，提供要展示的数据，现在一般包括数据Dao和行为Service；
view（视图）：负责进行模型的展示，一般就是用于用户交互；
Controller（控制器）：调度model和view，接受请求，委托给模型处理，返回数据，由视图展示；

各层作用：
控制器：获得表单数据、调用业务逻辑、转向指定页面；
模型层：业务逻辑、保存数据状态；
视图：显示页面；

SpringMVC概念

SpringMVC是Spring全家桶的一部分，是基于java实现mvc的轻量级web框架；
Spring的web框架围绕DispatcherServlet设计，它可以将请求分发到不同的处理器，本质还是Servlet

spring mvc工作原理

maven项目配置

新建一个Maven工程！导入pom依赖

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>tjw</groupId>
    <artifactId>mvc</artifactId>
    <version>1.0-SNAPSHOT</version>


    <!-- 设置jdk版本   -->
    <properties>
        <maven.compiler.target>1.8</maven.compiler.target>
        <maven.compiler.source>1.8</maven.compiler.source>
    </properties>

    <packaging>war</packaging>


    <dependencies>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.2.6.RELEASE</version>
        </dependency>

        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.2.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <!--   依赖范围   -->
            <scope>provided</scope>
        </dependency>

    </dependencies>

    <build>
        <resources>
            <resource>
                <directory>src/main/java</directory>
                <filtering>true</filtering>
                <includes>
                    <include>**/*.properties</include>
                    <include>**/*.xml</include>
                </includes>
            </resource>
        </resources>

        <!-- 必须添加 war 打包插件        -->
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-war-plugin</artifactId>
                <version>2.2</version>
                <configuration>
                    <!-- 指定web.xml的路径  -->
                    <webXml>web\WEB-INF\web.xml</webXml>
                    <!-- 指定jsp、js、css路径 -->
                    <warSourceDirectory>web</warSourceDirectory>
                </configuration>
            </plugin>
        </plugins>

    </build>


</project>

创建web文件夹

web包结构

web.xml配置

web.xml 配置DispatcherServlet

<?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">

    <!--  配置前端控制器  -->
    <servlet>
        <servlet-name>DispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

        <!-- 配置springMVC需要加载的配置文件-->
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-mvc.xml</param-value>
        </init-param>
        <!--  启动时加载      -->
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>DispatcherServlet</servlet-name>
        <!-- 默认匹配所有的请求 -->
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

spring-mvc.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:aop="http://www.springframework.org/schema/aop"
       xmlns:util="http://www.springframework.org/schema/util"
       xmlns:context="http://www.springframework.org/schema/context"
       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-4.0.xsd
        http://www.springframework.org/schema/aop  http://www.springframework.org/schema/aop/spring-aop-4.0.xsd
        http://www.springframework.org/schema/util  http://www.springframework.org/schema/util/spring-util-4.0.xsd
        http://www.springframework.org/schema/context  http://www.springframework.org/schema/context/spring-context-4.0.xsd
        http://www.springframework.org/schema/tx  http://www.springframework.org/schema/tx/spring-tx-4.0.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">


    <context:component-scan base-package="com.mvc">
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>

    <!-- mvc 注解配置 -->
    <mvc:annotation-driven/>

    <!--    全部静态资源放行-->
    <mvc:default-servlet-handler/>

    <!-- 配置视图解析器   -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

    <context:annotation-config/>
</beans>

编写controller

package com.mvc.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class HelloController {


    @RequestMapping("/home")
    public String hello(){
        return "index";
    }
}

编写jsp页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>hello mvc</h1>
</body>
</html>

Tomcat配置

1、添加Tomcat server

2、添加 war 并指定项目路径

3、运行Tomcat

访问：http://localhost:8080/home