SpringMVC interceptor and springmvc blocker

SpringMVC interceptor and springmvc blocker

1. Create an interceptor class LoginInterceptor

2. This interceptor needs to implement the HandlerInterceptor interface.

3. After implementing the interface, there are three implementation methods: preHandle, postHandle, and afterCompletion.

PreHandle is the function that is executed before the method is executed.

PostHandle indicates the function to be executed after the method is executed.

AfterCompletion is the method in which the entire DispatcherServlet processing is completed (equivalent to executing a method later than postHandle)

 

# We mainly use the preHandle method to execute the function "return false" to indicate that the execution fails and is not followed by the execution. If return true indicates that the execution is successful, the subsequent code is directly executed.

# Configure an interceptor for the XML file