Spring Boot Adding Http Request Interceptors

To add interceptor to a spring boot application, do the following

1. Create an interceptor class

   public class MyCustomInterceptor implements HandlerInterceptor{
   
       //unimplemented methods comes here. Define the following method so that it     
       //will handle the request before it is passed to the controller.
   
       @Override
       public boolean preHandle(HttpServletRequest request,HttpServletResponse  response){
       //your custom logic here.
           return true;
       }
   }
   

2. Define a configuration class

   @Configuration
   public class MyConfig extends WebMvcConfigurerAdapter{
       @Override
       public void addInterceptors(InterceptorRegistry registry){
           registry.addInterceptor(new MyCustomInterceptor()).addPathPatterns("/**");
       }
   }
   

3. Thats it. Now all your requests will pass through the logic defined under preHandle() method of MyCustomInterceptor.

WebMvcConfigurerAdapter will be deprecated with Spring 5. From its Javadoc:

@deprecated as of 5.0 {@link WebMvcConfigurer} has default methods (made possible by a Java 8 baseline) and can be implemented directly without the need for this adapter

As stated above, what you should do is implementing WebMvcConfigurer and overriding addInterceptors method.

@Configuration
public class WebMvcConfig implements WebMvcConfigurer {

    @Override
    public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(new MyCustomInterceptor());
    }
}

Since you're using Spring Boot, I assume you'd prefer to rely on Spring's auto configuration where possible. To add additional custom configuration like your interceptors, just provide a configuration or bean of WebMvcConfigurerAdapter.

Here's an example of a config class:

@Configuration
public class WebMvcConfig extends WebMvcConfigurerAdapter {

  @Autowired 
  HandlerInterceptor yourInjectedInterceptor;

  @Override
  public void addInterceptors(InterceptorRegistry registry) {
    registry.addInterceptor(...)
    ...
    registry.addInterceptor(getYourInterceptor()); 
    registry.addInterceptor(yourInjectedInterceptor);
    // next two should be avoid -- tightly coupled and not very testable
    registry.addInterceptor(new YourInterceptor());
    registry.addInterceptor(new HandlerInterceptor() {
        ...
    });
  }
}

NOTE do not annotate this with @EnableWebMvc, if you want to keep Spring Boots auto configuration for mvc.