2017.3.31 Spring MVC Tutorial (iii) Request mapping (static file access, interceptors)

Learning Blog: http://elf8848.iteye.com/blog/875830/

Version used in my project: 4.2.0. Blog time earlier, 11, learning is Spring3 MVC. I do not know if there is any change in the version of the larger features.

Spring MVC Tutorial (iii) interceptors

Interceptors in 1.Spring

(1) Interceptor interface

Spring provides an interceptor interface. Implement this interface or inherit this class, you can implement your own interceptor.

Org.springframework.web.servlet.  handlerinterceptor interface 2 Org.springframework.web.servlet.handler.  Handlerinterceptoradapter Adapter 

Implements   handlerinterceptor// slightly   

Handlerinteceptor has 3 methods: preprocessing, post-processing (call service and return Modelandview, but no page rendering), return processing (page already rendered).

The object handler in the parameter is the next interceptor.

1//Action before executing2PublicBooleanPrehandle(HttpServletRequest request,httpservletresponse response, Object handler);34 // perform 5 public void   posthandle  (httpservletrequest Request,httpservletresponse response, Object handler,  Modelandview  Modelandview); 6 7 // Last execution, can be used to release resources 8 public void   aftercompletion  ( HttpServletRequest request,httpservletresponse response,  object Handler  , Exception ex)            

(2) The execution process of the Interceptor

2017.3.31 Spring MVC Tutorial (iii) Request mapping (static file access, interceptors)