Spring学习：四、在web开发中使用spring框架-蒲公英云

Spring学习：四、在web开发中使用spring框架

迷南。 2023-10-04 20:17 110阅读 0赞

6. 在web开发中使用spring框架

创建一个web项目

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导入相关依赖

<?xml version=”1.0” encoding=”UTF-8”?>

4.0.0
org.example
spring-webdemo
1.0-SNAPSHOT
war
spring-webdemo Maven Webapp
http://www.example.com
UTF-8
1.8
1.8
5.3.21

org.springframework
spring-context
${spring.version}

org.springframework
spring-test
${spring.version}

org.springframework
spring-web
${spring.version}

javax.servlet
javax.servlet-api
3.1.0
provided

javax.servlet.jsp
jsp-api
2.1
provided

junit
junit
4.12
test

org.slf4j
slf4j-log4j12
1.7.36

org.projectlombok
lombok
1.18.24

javax.inject
javax.inject
1
  <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>
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
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！
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();
    }
}