在web项目中集成Spring

在web项目中集成Spring 

一、使用Servlet进行集成测试

1.直接在Servlet 加载Spring 配置文件

1. ApplicationContext applicationContext = new ClassPathXmlApplicationContext("applicationContext.xml");
   HelloService helloService = (HelloService) applicationContext.getBean("helloService");
   helloService.sayHello();

问题： 每次请求都会加载Spring环境，初始化所有Bean ，性能问题 ！！！

解决方案一： 将代码放入Servlet init 中 ， 无法保证所有Servlet都能使用 ApplicationContext 

解决方案二： ServletContext，在tomcat启动时， 加载Spring配置文件，获得对象 ，放入ServletContext 

* ServletContextListener 

 

2.导入spring-web.jar

保存 ContextLoaderListener 完成在Servlet初始化阶段，加载Spring配置文件，将工厂对象放入 ServletContext 

 

3.配置web.xml 

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

* 默认读取 WEB-INF/applicationContext.xml 

配置全局参数 contextConfigLocation 指定 配置文件位置 

1. <context-param>
       <param-name>contextConfigLocation</param-name>
       <param-value>classpath:applicationContext.xml</param-value>
   </context-param>

4.修改Servlet代码 

从ServletContext中获得 Spring工厂 

第一种：

1. WebApplicationContext applicationContext = (WebApplicationContext) getServletContext().getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);

 

第二种：

1. WebApplicationContext applicationContext = WebApplicationContextUtils.getWebApplicationContext(getServletContext());

 

**********************************************************************************完整代码*********************************************************************************

1)编写service(bean)：

1. public class HelloService{
       public void sayHello(){
           System.out.println("hello,Spring web");
       }
   }

2)注册bean：

1. <?xml version="1.0" encoding="UTF-8"?>
   <beansxmlns="http://www.springframework.org/schema/beans"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="
   http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd">
   <beanid="helloService"class="cn.itcast.service.HelloService"></bean>
   </beans>

3)配置web.xml文件

1. <?xml version="1.0" encoding="UTF-8"?>
   <web-appversion="2.5"
   xmlns="http://java.sun.com/xml/ns/javaee"
   xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
   xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
   http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
   <!-- 配置Spring 监听器 -->
   <listener>
   <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
   </listener>
   <!-- 配置Spring配置文件所在位置 -->
   <context-param>
   <param-name>contextConfigLocation</param-name>
   <param-value>classpath:applicationContext.xml</param-value>
   </context-param>
   <display-name></display-name>
   <servlet>
   <servlet-name>HelloServlet</servlet-name>
   <servlet-class>cn.itcast.servlet.HelloServlet</servlet-class>
   </servlet>
   
   <servlet-mapping>
   <servlet-name>HelloServlet</servlet-name>
   <url-pattern>/hello</url-pattern>
   </servlet-mapping>
   <welcome-file-list>
   <welcome-file>index.jsp</welcome-file>
   </welcome-file-list>
   </web-app>

4)编写servlet(测试)

1. public class HelloServletextendsHttpServlet{
   
   　　public void doGet(HttpServletRequest request,HttpServletResponse response)throws ServletException,IOException{
   　　     WebApplicationContext applicationContext =WebApplicationContextUtils.getWebApplicationContext(getServletContext());
           HelloService helloService =(HelloService) applicationContext.getBean("helloService");
           helloService.sayHello();
      }
   
      publicvoid doPost(HttpServletRequest request,HttpServletResponse response) throws ServletException,IOException{
        doGet(request, response);
      }
   }

 

二、Spring 整合 junit4 测试 

1、 导入spring-test.jar  

2、 编写测试用例 

1. @RunWith(SpringJUnit4ClassRunner.class)
   @ContextConfiguration(locations = "classpath:applicationContext.xml") // 指定配置文件位置
   public class HelloServiceTest {
       @Autowired
       private HelloService helloService; // 注入需要测试对象
       @Test
       // 测试
       public void demo2() {
           helloService.sayHello(); // 调用测试方法
       }
   }