Spring - Execute code before controller's method is invoked

Question

Is there any annotation similar to @PreAuthorize or @PreFilter that I can use to run code before a method in the Controller is invoked?

I need to add info to the request context (specific to the method being called) to be then retrieved by the ExceptionHandler.

For example

@RestController
public MyController{

  @UnkwonwAnnotation("prepareContext(request.getAgentId())"){
  public ResponseEntity method1(RequestA requestA) {
    ...
  }

  @UnkwonwAnnotation("prepareContext(request.getUserName())"){
  public ResponseEntity method1(RequestB requestB) {
    ...
  }

}

I could actually just use @PreAuthorize but doesn't feel right

Answer 1

You Can add interceptor for this

Sample Interceptor

public class CustomInterceptor implements HandlerInterceptor {

    
    @Override
    public boolean preHandle(HttpServletRequest request,HttpServletResponse  response) {
    //Add Login here 
        return true;
    }
} 

Configuration

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

Hope this helps

Answer 2

Maybe a good option is implement a custom filter that runs every time that a request is received.

You need extend "OncePerRequestFilter" and overwrite the method "doFilterInternal"

public class CustomFilter extends OncePerRequestFilter {

    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response,
                                    FilterChain filterChain) throws ServletException, IOException {

        //Add attributes to request
        request.getSession().setAttribute("attrName", new String("myValue"));

        // Run the method requested by petition
        filterChain.doFilter(request, response);

        //Do something after method runs if you need.

    }
}

After you have to register the filter in Spring with FilterRegistrationBean. If you have Spring security yo need add your filter after security filter.