Spring笔记（4）

<!--    servlet-->
    <dependency>
      <groupId>javax.servlet</groupId>
      <artifactId>javax.servlet-api</artifactId>
      <version>4.0.1</version>
      <scope>provided</scope>
    </dependency>
<!--    servlet-jsp-->
    <dependency>
      <groupId>javax.servlet.jsp</groupId>
      <artifactId>javax.servlet.jsp-api</artifactId>
      <version>2.2.1</version>
      <scope>provided</scope>
    </dependency>
<!--    spring-context-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-context</artifactId>
      <version>5.0.5.RELEASE</version>
    </dependency>
<!--    jdbc-druid-->
    <dependency>
      <groupId>com.alibaba</groupId>
      <artifactId>druid</artifactId>
      <version>1.0.9</version>
    </dependency>
<!--    jdbc-c3p0-->
    <dependency>
      <groupId>c3p0</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.1.2</version>
    </dependency>
<!--    spring-web-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-web</artifactId>
      <version>5.0.5.RELEASE</version>
    </dependency>

<plugin>
  <groupId>org.apache.tomcat.maven</groupId>
  <artifactId>tomcat7-maven-plugin</artifactId>
  <version>2.2</version>
</plugin>

public class ApplicationContextLoaderUtil {
    public static ApplicationContext getApplicationContext(ServletContext servletContext){
        //在域中获取applicationContext对象
        ApplicationContext app = (ApplicationContext) servletContext.getAttribute("app");
        //测试
        System.out.println("通过工具类获取app");
        return app;
    }
}

<!--  全局初始化参数-->
  <!--applicationContext文件名-->
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
  </context-param>

<!--  配置监听器-->
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    //在servletContext中获取ApplicationContext对象
    //获取servletContext
    ServletContext servletContext = request.getServletContext();
    //获取app对象(使用工具包中的方法)
    ApplicationContext app = WebApplicationContextUtils.getWebApplicationContext(servletContext);
    //获取userService
    UserService userService = app.getBean(UserService.class);
    userService.save();

<scope>provided</scope>

<context:component-scan base-package="dao"/>
<context:component-scan base-package="service"/>