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arthas/tutorials/katacoda/case-get-spring-context-en/case-get-spring-context.md

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In this case, the user can get the spring context, get the bean, and invoke the method.
### Use the tt command to record the invocation of the specified method
`tt` is TimeTunnel, which records the parameters and return value of each invocation of the specified method.
* https://arthas.aliyun.com/doc/tt.html
`tt -t org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter invokeHandlerMethod`{{execute T2}}
Visit: https://[[HOST_SUBDOMAIN]]-80-[[KATACODA_HOST]].environments.katacoda.com/user/1
You can see that the `tt` command record an invocation:
```bash
$ tt -t org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdaptePress Q or Ctrl+C to abort.
Affect(class-cnt:1 , method-cnt:1) cost in 252 ms.
INDE TIMESTAMP COST( IS-R IS- OBJECT CLASS METHOD
X ms) ET EXP
-----------------------------------------------------------------------------------------
1000 2019-02-15 4.583 true fal 0xc93cf1a RequestMappingHand invokeHandlerMethod
15:38:32 923 se lerAdapter
```
### Use the tt command to get the spring context from the invocation record.
Type `Q`{{execute T2}} or `Ctrl + C` to exit the `tt -t` command above.
`tt -i 1000 -w 'target.getApplicationContext()'`{{execute T2}}
```bash
$ tt -i 1000 -w 'target.getApplicationContext()'
@AnnotationConfigEmbeddedWebApplicationContext[
reader=@AnnotatedBeanDefinitionReader[org.springframework.context.annotation.AnnotatedBeanDefinitionReader@2e457641],
scanner=@ClassPathBeanDefinitionScanner[org.springframework.context.annotation.ClassPathBeanDefinitionScanner@6eb38026],
annotatedClasses=null,
basePackages=null,
]
Affect(row-cnt:1) cost in 439 ms.
```
## Get the spring bean and invoke method
`tt -i 1000 -w 'target.getApplicationContext().getBean("helloWorldService").getHelloMessage()'`{{execute T2}}
The result is:
```bash
$ tt -i 1000 -w 'target.getApplicationContext().getBean("helloWorldService").getHelloMessage()'
@String[Hello World]
Affect(row-cnt:1) cost in 52 ms.
```