springmvc入门案例

1、导包

基于maven

<properties>
    <!--指定springmvc版本-->
    <spring.version>5.0.2.RELEASE</spring.version>
 </properties>

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

<!-- https://mvnrepository.com/artifact/javax.servlet/javax.servlet-api -->
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>4.0.1</version>
    <scope>provided</scope>
</dependency>

<!-- https://mvnrepository.com/artifact/javax.servlet.jsp/javax.servlet.jsp-api -->
<dependency>
    <groupId>javax.servlet.jsp</groupId>
    <artifactId>javax.servlet.jsp-api</artifactId>
    <version>2.3.3</version>
    <scope>provided</scope>
</dependency>

2、在web.xml中配置核心控制器

过滤器可配，可不配

<!--配置springmvc前端控制器-->
  <servlet>
    <servlet-name>DispatcherServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <!--加载springmvc配置文件-->
    <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:springmvc.xml</param-value>
    </init-param>
    <!--指定控制器创建时间-->
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>DispatcherServlet</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>

  <!--配置编码过滤器-->
  <filter>
    <filter-name>CharacterEncodingFilter</filter-name>
    <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    <!--设置编码-->
    <init-param>
      <param-name>encoding</param-name>
      <param-value>UTF-8</param-value>
    </init-param>
  </filter>
  <filter-mapping>
    <filter-name>CharacterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

3、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">

    <!--指定要扫描的包-->
    <context:component-scan base-package="com.yl"></context:component-scan>
    <!--配置视图解析器-->
    <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/pages/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>
    <!--开启springmvc注解支持-->
    <mvc:annotation-driven></mvc:annotation-driven>
</beans>

4、编写index.jsp

<body>
    <h3>入门案例</h3>
    <a href="${ pageContext.request.contextPath }/hello">入门案例</a> 
</body>

5、编写控制器

package cn.itcast.controller; 

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

/*** 控制器
*@author rt 
*/ 
@Controller 
public class HelloController { 
    /*** 接收请求
    * @return 
    */ 
    @RequestMapping(path="/hello") 
    public String sayHello() { 
        System.out.println("Hello SpringMVC!!"); 
        return "success"; 
    } 
}

6、编写success.jsp的成功页面

success.jsp的成功页面放在WEB-INF目录下创建的pages文件夹

<body>
    <h3>入门成功！！</h3> 
</body>

7、启动tomcat服务器，测试

8、入门案例执行过程分析

入门案例的执行流程

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
开启了注解扫描，那么HelloController对象就会被创建
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
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
Tomcat服务器渲染页面，做出响应

posted @ 2020-10-19 09:36 Y-wee 阅读(112) 评论(0) 收藏举报

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