Go to: how to obtain the bean managed by Spring and the bean managed by spring

Go to: how to obtain the bean managed by Spring and the bean managed by spring

Original article:Http://blog.csdn.net/a9529lty/article/details/42145545

1. When loading in servlet mode,
[Web. xml]

Xml Code

1. <Servlet>
2. <Servlet-name>SpringMVC</Servlet-name>
3. <Servlet-class>Org. springframework. web. servlet. DispatcherServlet</Servlet-class>
4. <Init-param>
5. <Param-name>ContExtConfigLocation</Param-name>
6. <Param-value>Classpath *:/springMVC. xml</Param-value>
7. </Init-param>
8. <Load-on-startup>1</Load-on-startup>
9. </Servlet>

The key of the spring container in ServletContext is org. springframework. web. servlet. FrameworkServlet. CONTEXT. springMVC.
Note that springMVC is the configuration value of your servlet-name and must be modified in a timely manner.

Java code

1. ServletContext SC = omitted
2. WebApplicationContext attr = (WebApplicationContext) SC. getAttribute ("org. springframework. web. servlet. FrameworkServlet. CONTEXT. springMVC ");

 

2. listener loading:
[Web. xml]

Xml Code

1. <Context-param>
2. <Param-name>ContextConfigLocation</Param-name>
3. <Param-value>/WEB-INF/applicationContext</Param-value>
4. </Context-param>
6. <Listener>
7. <Listener-class>Org. springframework. web. context. ContextLoaderListener</Listener-class>
8. </Listener>

[Jsp/servlet] can be obtained in this way

Java code

1. ServletContext context = getServletContext ();
2. WebApplicationContext applicationContext = WebApplicationContextUtils. getWebApplicationContext (context );

 

3. A general method is provided. The first two methods are not common and can be discarded.
Add the following to the configuration file:

Xml Code

1. <! -- Used to hold ApplicationContext. You can use the static method of SpringContextHolder. getBean ('xxxx') to obtain the spring bean object -->
2. <BeanClass = "com. xxxxx. SpringContextHolder" lazy-init = "false"/>

 

Java code

1. Import org. springframework. context. ApplicationContext;
2. Import org. springframework. context. ApplicationContextAware;
3. /**
4. * Save Spring ApplicationContext as a static variable. You can retrieve ApplicaitonContext from any code anywhere.
5. *
6. */
7. Public class SpringContextHolder implements ApplicationContextAware {
8. Private static ApplicationContext applicationContext;
10. /**
11. * Implements the context injection function of the ApplicationContextAware interface and saves it to static variables.
12. */
13. Public void setApplicationContext (ApplicationContext applicationContext ){
14. SpringContextHolder. applicationContext = applicationContext; // NOSONAR
15. }
17. /**
18. * Obtain ApplicationContext stored in static variables.
19. */
20. Public static ApplicationContext getApplicationContext (){
21. CheckApplicationContext ();
22. Return applicationContext;
23. }
25. /**
26. * Obtain the Bean from the static variable ApplicationContext and automatically convert it to the type of the assigned object.
27. */
28. @ SuppressWarnings ("unchecked ")
29. Public static <T> T getBean (String name ){
30. CheckApplicationContext ();
31. Return (T) applicationContext. getBean (name );
32. }
34. /**
35. * Obtain the Bean from the static variable ApplicationContext and automatically convert it to the type of the assigned object.
36. */
37. @ SuppressWarnings ("unchecked ")
38. Public static <T> T getBean (Class <T> clazz ){
39. CheckApplicationContext ();
40. Return (T) applicationContext. getBeansOfType (clazz );
41. }
43. /**
44. * Clear static applicationContext variables.
45. */
46. Public static void cleanApplicationContext (){
47. ApplicationContext = null;
48. }
50. Private static void checkApplicationContext (){
51. If (applicationContext = null ){
52. Throw new IllegalStateException ("applicaitonContext is not injected. Define SpringContextHolder in applicationContext. xml ");
53. }
54. }
55. }