06_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");
2. HelloService helloService = (HelloService) applicationContext.getBean("helloService");
3. 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>
2.     <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
3. </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>
2.     <param-name>contextConfigLocation</param-name>
3.     <param-value>classpath:applicationContext.xml</param-value>
4. </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. publicclassHelloService{
2. publicvoid sayHello(){
3. System.out.println("hello,Spring web");
4. }
5. }

2)注册bean：

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

3)配置web.xml文件

1. <?xml version="1.0" encoding="UTF-8"?>
2. <web-appversion="2.5"
3. xmlns="http://java.sun.com/xml/ns/javaee"
4. xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
5. xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
6. http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
7. <!-- 配置Spring 监听器 -->
8. <listener>
9. <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
10. </listener>
11. <!-- 配置Spring配置文件所在位置 -->
12. <context-param>
13. <param-name>contextConfigLocation</param-name>
14. <param-value>classpath:applicationContext.xml</param-value>
15. </context-param>
17. <display-name></display-name>
19. <servlet>
20. <servlet-name>HelloServlet</servlet-name>
21. <servlet-class>cn.itcast.servlet.HelloServlet</servlet-class>
22. </servlet>
23. 
    
24. <servlet-mapping>
25. <servlet-name>HelloServlet</servlet-name>
26. <url-pattern>/hello</url-pattern>
27. </servlet-mapping>
29. <welcome-file-list>
30. <welcome-file>index.jsp</welcome-file>
31. </welcome-file-list>
32. </web-app>

4)编写servlet(测试)

1. publicclassHelloServletextendsHttpServlet{
3. publicvoid doGet(HttpServletRequest request,HttpServletResponse response)
4. throwsServletException,IOException{
5. WebApplicationContext applicationContext =WebApplicationContextUtils.getWebApplicationContext(getServletContext());
6. HelloService helloService =(HelloService) applicationContext.getBean("helloService");
7. helloService.sayHello();
8. }
10. publicvoid doPost(HttpServletRequest request,HttpServletResponse response)
11. throwsServletException,IOException{
12. doGet(request, response);
13. }
15. }

 

二、Spring 整合 junit4 测试 

1、 导入spring-test.jar  

2、 编写测试用例 

1. @RunWith(SpringJUnit4ClassRunner.class)
2. @ContextConfiguration(locations = "classpath:applicationContext.xml") // 指定配置文件位置
3. public class HelloServiceTest {
4.     @Autowired
5.     private HelloService helloService; // 注入需要测试对象
6.     @Test
7.     // 测试
8.     public void demo2() {
9.         helloService.sayHello(); // 调用测试方法
10.     }
11. }

 

 

来自为知笔记(Wiz)