Spring学习：四、在web开发中使用spring框架

迷南。 2023-10-04 20:17 43阅读 0赞

### 6. 在web开发中使用spring框架 ###

> 1.  创建一个web项目
> 
> ![在这里插入图片描述][f85e765b117740389f925303edf45618.png]  
> ![>\[外链图片转存失败,源站可能有防盗链机制,建议将图片保存下来直接上传(img-lXyPOVPl-1670413867380)(assets/image-20220801192505321.png)\]][img-lXyPOVPl-1670413867380_assets_image-20220801192505321.png]![在这里插入图片描述][cdb6a733bf3444559ca449c6235bc3e4.png]  
> 2. 导入相关依赖
> 
>     <?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.example</groupId>
>       <artifactId>spring-webdemo</artifactId>
>       <version>1.0-SNAPSHOT</version>
>       <packaging>war</packaging>
>     
>       <name>spring-webdemo Maven Webapp</name>
>       
>       <url>http://www.example.com</url>
>     
>       <properties>
>         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
>         <maven.compiler.source>1.8</maven.compiler.source>
>         <maven.compiler.target>1.8</maven.compiler.target>
>         <spring.version>5.3.21</spring.version>
>       </properties>
>     
>       <dependencies>
>         <dependency>
>           <groupId>org.springframework</groupId>
>           <artifactId>spring-context</artifactId>
>           <version>${spring.version}</version>
>         </dependency>
>         <dependency>
>           <groupId>org.springframework</groupId>
>           <artifactId>spring-test</artifactId>
>           <version>${spring.version}</version>
>         </dependency>
>         
>         <dependency>
>           <groupId>org.springframework</groupId>
>           <artifactId>spring-web</artifactId>
>           <version>${spring.version}</version>
>         </dependency>
>         
>         <dependency>
>           <groupId>javax.servlet</groupId>
>           <artifactId>javax.servlet-api</artifactId>
>           <version>3.1.0</version>
>           <scope>provided</scope>
>         </dependency>
>         
>         <dependency>
>           <groupId>javax.servlet.jsp</groupId>
>           <artifactId>jsp-api</artifactId>
>           <version>2.1</version>
>           <scope>provided</scope>
>         </dependency>
>         <dependency>
>           <groupId>junit</groupId>
>           <artifactId>junit</artifactId>
>           <version>4.12</version>
>           <scope>test</scope>
>         </dependency>
>     
>         
>         <dependency>
>           <groupId>org.slf4j</groupId>
>           <artifactId>slf4j-log4j12</artifactId>
>           <version>1.7.36</version>
>         </dependency>
>     
>         <dependency>
>           <groupId>org.projectlombok</groupId>
>           <artifactId>lombok</artifactId>
>           <version>1.18.24</version>
>         </dependency>
>     
>         <dependency>
>           <groupId>javax.inject</groupId>
>           <artifactId>javax.inject</artifactId>
>           <version>1</version>
>         </dependency>
>       </dependencies>
>     
>     
>       <build>
>         <finalName>spring-webdemo</finalName>
>         <pluginManagement>
>           <plugins>
>             <plugin>
>               <artifactId>maven-clean-plugin</artifactId>
>               <version>3.1.0</version>
>             </plugin>
>             
>             <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>
> 
> 1.  在web.xml文件中配置监听器,用于监听web服务器的启动, 创建Spring容器
>     
>         
>         <listener>
>             <listener-class>
>                 org.springframework.web.context.ContextLoaderListener
>             </listener-class>
>         </listener>
>     
>     如果没有配置监听器,那么Spring默认加载 WEB-INF/applicationContext.xml,而我们的spring的配置文件是位于
> 
> ![在这里插入图片描述][74196cd7fc044209b79d838d23f0fab8.png]

> 使用`<context-param>`配置spring的配置文件路径:
> 
>     
>     <context-param>
>        <param-name>contextConfigLocation</param-name>
>        <param-value>classpath:applicationContext.xml</param-value>
>     </context-param>
> 
> > 通过上面配置的spring的监听器,那么在tomcat启动时，spring工厂进行创建 ！
> 
> 1.  创建Servlet,在Servlet中获取Spring容器对象,通过getBean()获取service层的对象
> 
>     package com.suke.web;
>     
>     import com.suke.service.UserService;
>     import org.springframework.context.ApplicationContext;
>     import org.springframework.web.context.WebApplicationContext;
>     import org.springframework.web.context.support.WebApplicationContextUtils;
>     
>     import javax.servlet.ServletException;
>     import javax.servlet.annotation.WebServlet;
>     import javax.servlet.http.HttpServlet;
>     import javax.servlet.http.HttpServletRequest;
>     import javax.servlet.http.HttpServletResponse;
>     import java.io.IOException;
>     
>     @WebServlet(name = "UserServlet",value = "/userServlet")
>     public class UserServlet extends HttpServlet {
>          
>         protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
>          
>     
>         }
>     
>         protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
>          
>             //1.第一种方式:
>             //ApplicationContext applicationContext = (ApplicationContext) this.getServletContext().getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);
>     
>             //2.第二种方式
>             ApplicationContext applicationContext = WebApplicationContextUtils.getWebApplicationContext(this.getServletContext());
>     
>             UserService userService = applicationContext.getBean("userService", UserService.class);
>             userService.addUser();
>         }
>     }

[f85e765b117740389f925303edf45618.png]: https://img-blog.csdnimg.cn/f85e765b117740389f925303edf45618.png
[img-lXyPOVPl-1670413867380_assets_image-20220801192505321.png]: https://img-blog.csdnimg.cn/949326572e344b399471adcc9f376a40.png
[cdb6a733bf3444559ca449c6235bc3e4.png]: https://img-blog.csdnimg.cn/cdb6a733bf3444559ca449c6235bc3e4.png
[74196cd7fc044209b79d838d23f0fab8.png]: https://img-blog.csdnimg.cn/74196cd7fc044209b79d838d23f0fab8.png