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arthas/tutorials/katacoda/command-vmtool-en/vmtool-spring.md

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Next, use the `vmtool` command to find objects in spring.
### Find spring context
`vmtool --action getInstances --className org.springframework.context.ApplicationContext `{{execute T2}}
```bash
$ vmtool --action getInstances --className org.springframework.context.ApplicationContext
@ApplicationContext[][
@AnnotationConfigEmbeddedWebApplicationContext[org.springframework.boot.context.embedded.AnnotationConfigEmbeddedWebApplicationContext@12028586: startup date [Thu May 13 16:08:38 UTC 2021]; root of context hierarchy],
]
```
### Specify the number of expanded layers of returned results
> The return result of the `getInstances` action is bound to the `instances` variable, which is an array.
> The expansion level of the result can be specified by the `-x`/`--expand` parameter, the default value is 1.
`vmtool --action getInstances --className org.springframework.context.ApplicationContext -x 2`{{execute T2}}
### Execute expression
> The return result of the `getInstances` action is bound to the `instances` variable, which is an array. The specified expression can be executed through the `--express` parameter.
Find the names of all spring beans:
`vmtool --action getInstances --className org.springframework.context.ApplicationContext --express 'instances[0].getBeanDefinitionNames()'`{{execute T2}}
Call the `userController.findUserById(1)` method:
`vmtool --action getInstances --className org.springframework.context.ApplicationContext --express 'instances[0].getBean("userController").findUserById(1)'`{{execute T2}}
```
$ vmtool --action getInstances --className org.springframework.context.ApplicationContext --express'instances[0].getBean("userController").findUserById(1)'
@User[
id=@Integer[1],
name=@String[name1],
]
```
### Find all spring mapping objects
`vmtool --action getInstances --className org.springframework.web.servlet.HandlerMapping`{{execute T2}}
```bash
$ vmtool --action getInstances --className org.springframework.web.servlet.HandlerMapping
@HandlerMapping[][
@SimpleUrlHandlerMapping[org.springframework.web.servlet.handler.SimpleUrlHandlerMapping@5d3819c8],
@EmptyHandlerMapping[org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport$EmptyHandlerMapping@11d509ba],
@RequestMappingHandlerMapping[org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping@56a5f2e3],
@WelcomePageHandlerMapping[org.springframework.boot.autoconfigure.web.WebMvcAutoConfiguration$WelcomePageHandlerMapping@4c0a4ed3],
@EmptyHandlerMapping[org.springframework.web.servlet.config.annotation.WebMvcConfigurationSupport$EmptyHandlerMapping@51e1f8c3],
@BeanNameUrlHandlerMapping[org.springframework.web.servlet.handler.BeanNameUrlHandlerMapping@68c0a39c],
@SimpleUrlHandlerMapping[org.springframework.web.servlet.handler.SimpleUrlHandlerMapping@110b768d],
]
```