创建一个maven项目,同时选择webapp模块,首先导入所需的maven坐标导入jar包
1、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>org.example</groupId>
<artifactId>springmvc_day01_02_start</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>war</packaging>
<name>springmvc_day01_02_start Maven Webapp</name>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.7</maven.compiler.source>
<maven.compiler.target>1.7</maven.compiler.target>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>5.2.9.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>5.2.9.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>5.2.9.RELEASE</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>servlet-api</artifactId>
<version>2.5</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet.jsp</groupId>
<artifactId>jsp-api</artifactId>
<version>2.0</version>
<scope>provided</scope>
</dependency>
</dependencies>
<build>
<finalName>springmvc_day01_02_start</finalName>
<pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
<plugins>
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.1.0</version>
</plugin>
<!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.1</version>
</plugin>
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>3.2.2</version>
</plugin>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
</plugin>
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
2、配置servlet
同时配置加载sprinmvc的配置文件,使配置文件生效。
web.xml
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
<display-name>Archetype Created Web Application</display-name>
<servlet>
<servlet-name>dispatcherServlet</servlet-name>
<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
<!-- 配置Servlet的初始化参数,读取springmvc的配置文件,创建spring容器 -->
<init-param>
<param-name>contextConfigLocation</param-name>
<param-value>classpath:springmvc.xml</param-value>
</init-param>
<!-- 配置servlet启动时加载对象 -->
<load-on-startup>1</load-on-startup>
</servlet>
<servlet-mapping>
<servlet-name>dispatcherServlet</servlet-name>
<url-pattern>/</url-pattern>
</servlet-mapping>
</web-app>
3、springmvc配置文件
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:mvc="http://www.springframework.org/schema/mvc"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="
http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/mvc
http://www.springframework.org/schema/mvc/spring-mvc.xsd
http://www.springframework.org/schema/context
http://www.springframework.org/schema/context/spring-context.xsd">
<!-- spring扫描的包 -->
<context:component-scan base-package="cn"></context:component-scan>
<!-- 配置视图解析器 -->
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="prefix" value="/WEB-INF/pages/"></property>
<property name="suffix" value=".jsp"></property>
</bean>
<!-- 开启注解支持 -->
<mvc:annotation-driven></mvc:annotation-driven>
</beans>
- mvc:annotation-driven说明
在 SpringMVC 的各个组件中,处理器映射器、处理器适配器、视图解析器称为 SpringMVC 的三大组件。
使用<mvc:annotation-driven> 自动加载 RequestMappingHandlerMapping (处理映射器)和 RequestMappingHandlerAdapter ( 处 理 适 配 器 ) , 可 用 在 SpringMVC.xml 配 置 文 件 中 使 用 <mvc:annotation-driven>替代注解处理器和适配器的配置。
4、主页面index.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h1>第一个SpringMVC</h1>
<a href="hello">开始测试</a>
</body>
</html>
5、处理hello请求
@Controller
public class helloSpringMvc {
@RequestMapping(value = "/hello")
public String sayHello() {
System.out.println("Hello SpringMVC");
return "hello";
}
}
6、成功页面
hello.jsp
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h1>测试成功</h1>
</body>
</html>
7、测试运行
选择tomcat服务器运行
点击过后
流程分析
1、当启动Tomcat服务器的时候,因为配置了load-on-startup标签,所以会创建DispatcherServlet对象, 就会加载springmvc.xml配置文件 。
2、开启了注解扫描,那么HelloController对象就会被创建。
3、从index.jsp发送请求,请求会先到达DispatcherServlet核心控制器,根据配置@RequestMapping注解 找到执行的具体方法 。
4、根据执行方法的返回值,再根据配置的视图解析器,去指定的目录下查找指定名称的JSP文件 。
5、 Tomcat服务器渲染页面,做出响应 。
图解
三大组件处理过程分析
视频解析过程:黑马程序员springmvc教程