Question - What are Spring Interceptors?
Answer -
Spring Interceptors are used to pre-handle and post-handle the web requests in Spring MVC which are handled by Spring Controllers. This can be achieved by the HandlerInterceptor interface. These handlers are used for manipulating the model attributes that are passed to the controllers or the views.
The Spring handler interceptor can be registered for specific URL mappings so that it can intercept only those requests. The custom handler interceptor must implement the HandlerInterceptor interface that has 3 callback methods that can be implemented:
- preHandle()
- postHandle()
- afterCompletion()
The only problem with this interface is that all the methods of this interface need to be implemented irrespective of its requirements. This can be avoided if our handler class extends the HandlerInterceptorAdapter class that internally implements the HandlerInterceptor interface and provides default blank implementations.