浅谈Spring Context加载方式

 public static void main(String[] args) {
    ClassPathXmlApplicationContext xmlApplicationContext = new ClassPathXmlApplicationContext("classpath:spring-context.xml");
    DemoService demoService = (DemoService) xmlApplicationContext.getBean("demoService");
    String text = demoService.hello();
    System.out.println(text);
  }

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
    http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
    http://www.springframework.org/schema/context
    http://www.springframework.org/schema/context/spring-context-3.2.xsd"
    default-autowire="byName" default-lazy-init="false">

  <!-- 采用注释的方式配置bean -->
  <context:annotation-config/>
  <!-- 配置要扫描的包 -->
  <context:component-scan base-package="com.jin.lesson.context"/>
</beans>

 public static void main(String[] args) {
    AnnotationConfigApplicationContext annotationConfigApplicationContext = new AnnotationConfigApplicationContext();
    // 告诉要扫描的包，通常是应用的根目录的Application类
    annotationConfigApplicationContext.scan(Main.class.getPackage().getName());
    // 刷新上下文，使用得相应的bean注册成功
    annotationConfigApplicationContext.refresh();
    // 通过名称的方式获取相应的DemoService
    DemoService demoService = (DemoService) annotationConfigApplicationContext.getBean("demoService");
    String text = demoService.hello();
    System.out.println(text);
  }

<context:annotation-config/>

@Service(value = "demoService")
public class DemoService {
  public String hello() {
    return "hello world";
  }
}

  <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:spring/spring-context.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
    <async-supported>true</async-supported>
  </servlet>
  <servlet-mapping>
    <servlet-name>SpringMVC</servlet-name>
    <url-pattern>/</url-pattern>
  </servlet-mapping>

  <listener>
    <listener-class>
      org.springframework.web.context.ContextLoaderListener
    </listener-class>
  </listener>
  <listener>
    <listener-class>org.springframework.web.context.request.RequestContextListener</listener-class>
  </listener>

 @Override
  public void onStartup(ServletContext servletContext) throws ServletException {
    ServletRegistration.Dynamic dispatcher = servletContext.addServlet("dispatcher", DispatcherServlet.class);
    dispatcher.setInitParameter("contextConfigLocation", getClass().getName());
    dispatcher.setInitParameter("contextClass", AnnotationConfigWebApplicationContext.class.getName());
    dispatcher.addMapping("/*");
    dispatcher.setLoadOnStartup(1);
  }