springMVC接口与注解版本demo实现

Myth丶恋晨 2022-10-19 14:58 115阅读 0赞

tips:  
对于在一个工程下，有多个模块。如果不能访问页面，可能是因为没有装载成功，我也遇到这个问题。  
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解决方案：  
ctrl+shift+alt + S, 新建一个lib目录，导入模块的包，重新运行tomcat即可

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM5NDYzMTc1_size_16_color_FFFFFF_t_70 1]  
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# 一 实现controller接口 #

需要导入的依赖：

<?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.yang</groupId>
        <artifactId>springMVC-01-servlet</artifactId>
        <packaging>pom</packaging>
        <version>1.0-SNAPSHOT</version>
        <modules>
            <module>MVC-01-servlet</module>
            <module>MVC-02-helloMVC</module>
        </modules>
    
        <dependencies>
            
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
            </dependency>
            
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.47</version>
            </dependency>
            
            <dependency>
                <groupId>com.mchange</groupId>
                <artifactId>c3p0</artifactId>
                <version>0.9.5.2</version>
            </dependency>
    
            
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>servlet-api</artifactId>
                <version>2.5</version>
            </dependency>
            <dependency>
                <groupId>javax.servlet.jsp</groupId>
                <artifactId>jsp-api</artifactId>
                <version>2.2</version>
            </dependency>
            <dependency>
                <groupId>javax.servlet</groupId>
                <artifactId>jstl</artifactId>
                <version>1.2</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis</artifactId>
                <version>3.5.2</version>
            </dependency>
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis-spring</artifactId>
                <version>2.0.2</version>
            </dependency>
    
            
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-webmvc</artifactId>
                <version>5.1.9.RELEASE</version>
            </dependency>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-jdbc</artifactId>
                <version>5.1.9.RELEASE</version>
            </dependency>
        </dependencies>
    
        <build>
            <resources>
                <resource>
                    <directory>src/main/java</directory>
                    <includes>
                        <include>**/*.properties</include>
                        <include>**/*.xml</include>
                    </includes>
                    <filtering>false</filtering>
                </resource>
                <resource>
                    <directory>src/main/resources</directory>
                    <includes>
                        <include>**/*.properties</include>
                        <include>**/*.xml</include>
                    </includes>
                    <filtering>false</filtering>
                </resource>
            </resources>
        </build>
    </project>

## 1 在web.xml中加入与springMVC相关的配置 ##

<?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">
    
    <servlet>
        <servlet-name>springmvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:springmvc-servlet.xml</param-value>
    
    </init-param>
    
        <load-on-startup>1</load-on-startup>
    </servlet>
    
    
    
    
        <servlet-mapping>
            <servlet-name>springmvc</servlet-name>
            <url-pattern>/</url-pattern>
        </servlet-mapping>
    
    </web-app>

## 2 写springMVC的配置文件，即springMVC-servlet.xml文件： ##

### 2.1 处理映射器 ###

\#\#\#2.2 处理适配器  
\#\#\#2.3 视图解析器

<?xml version="1.0" encoding="UTF-8"?>
    <beans xmlns="http://www.springframework.org/schema/beans" 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">
    
    
    
        <bean class="org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping"/>
        <bean class="org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter"/>
        
        <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="InternalResourceViewResolver">
            
            <property name="prefix" value="/WEB-INF/jsp/"/>
            
            <property name="suffix" value=".jsp"/>
        </bean>
        <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver" id="InternalResourceViewResolver">
            
            <property name="prefix" value="/WEB-INF/jsp/"/>
            
            <property name="suffix" value=".jsp"/>
        </bean>
    
    
    
        <bean id="/hello" class="com.yang.controller.HelloController"/>
    </beans>

## 3 写controller类的具体实现，即实现controller接口 ##

package com.yang.controller;
    
    import org.springframework.web.servlet.ModelAndView;
    import org.springframework.web.servlet.mvc.Controller;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    public class HelloController implements Controller { 
        public ModelAndView handleRequest(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception { 
            ModelAndView modelAndView = new ModelAndView();
            //业务代码
            String s = "hello Spring MVC";
    
            //ModelAndView msg = modelAndView.addObject("msg", s);
            modelAndView.addObject("msg", s);
            modelAndView.setViewName("test");//跳到test.jsp下
            return modelAndView;
        }
    }

目录结构：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM5NDYzMTc1_size_16_color_FFFFFF_t_70 3]

# 二 使用@controller注解实现 #

需要把springmvc-servlet.xml文件变为如下，就能使用注解了；

<?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">
    
        
        <servlet>
            <servlet-name>SpringMVC</servlet-name>
            <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
            
            <init-param>
                <param-name>contextConfigLocation</param-name>
                <param-value>classpath:springmvc-servlet.xml</param-value>
            </init-param>
            
            <load-on-startup>1</load-on-startup>
        </servlet>
    
        
        <servlet-mapping>
            <servlet-name>SpringMVC</servlet-name>
            <url-pattern>/</url-pattern>
        </servlet-mapping>
    
    </web-app>

controller类为：

package com.yang.controller;
    
    import org.springframework.stereotype.Controller;
    import org.springframework.ui.Model;
    import org.springframework.web.bind.annotation.RequestMapping;
    
    @Controller
    @RequestMapping("/HelloController")
    public class HelloController { 
    
        //真实访问地址 : 项目名/HelloController/hello
        @RequestMapping("/hello")
        public String toHello(Model model){ 
            //向模型中添加属性msg与值，可以在JSP页面中取出并渲染
            model.addAttribute("msg","hello,SpringMVC");
           
            return "hello";  //会自动拼接成 //web-inf/jsp/hello.jsp
        }
    }

参考：  
[\[第一个SpringMVC！\]][SpringMVC]  
[SpringMVC03：RestFul和控制器][SpringMVC03_RestFul]  
[SpringMVC04：数据处理及跳转][SpringMVC04]

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[SpringMVC]: https://mp.weixin.qq.com/s?__biz=Mzg2NTAzMTExNg==&mid=2247483978&idx=1&sn=6711110a3b2595d6bb987ca02ee0a728&chksm=ce6104e9f9168dffb600f71f97f89c5581923948746b7e2e53a8f0287419ea9940e124c39b0e&scene=21#wechat_redirect
[SpringMVC03_RestFul]: https://mp.weixin.qq.com/s?__biz=Mzg2NTAzMTExNg==&mid=2247483993&idx=1&sn=abdd687e0f360107be0208946a7afc1d&chksm=ce6104faf9168dec5000de5ac600efd8e62ddffbd12a9bbd2e3fb786a4db3d7ee7c07d31d6d8&scene=21#wechat_redirect
[SpringMVC04]: https://mp.weixin.qq.com/s?__biz=Mzg2NTAzMTExNg==&mid=2247483998&idx=1&sn=97c417a2c1484d694c761a2ad27f217d&chksm=ce6104fdf9168deb32664243023d374b336f2a4260b55846b533a8be70d2f9bc97e45f4ede47&scene=21#wechat_redirect