Spring笔记（4）

集成Web环境

1.步骤

1. 导入Spring-web坐标

   <!--    spring-web-->
       <dependency>
         <groupId>org.springframework</groupId>
         <artifactId>spring-web</artifactId>
         <version>5.0.5.RELEASE</version>
       </dependency>
   

2. 将ApplicationContext.xml的文件名称存入web.xml的全局参数中

   <!--  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>
   

3. 配置监听器

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

4. 编写Servlet

5. 使用WebApplicationContextUtils获取ApplicationContext(获取的为子类WebApp..)

   //获取app对象(使用工具包中的方法)
   ApplicationContext app = WebApplicationContextUtils.getWebApplicationContext(servletContext);
   

2.pom.xml

<!--    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>

3.servlet具体实现

3.1工具包实现：(封装好的)

• ​ servlet中的app通过工具包中的方法获得（）
• ​ 在servletContext域中获得app对象
• ​ 域中app对象在监听器模块内部实现存储

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;
    }
}

3.2监听器实现（封装好的）

手动配置（web.xml中）

<!--  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>

内部封装好

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();

4.注意

配置pom.xml时：

servlet-api和servlet-jsp-api时应该加入范围

<scope>provided</scope>

applicationContext.xml中：

添加扫描注解

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