How to register a JavaEE filter in your Spring Boot application?

Question

I have the following Spring Boot controller and a JavaEE filter classes in my Spring Boot based REST application. Please note that I do not have a web.xml configured here.

http://localhost:8080/api/products -> Returns 200

The problem is that the interceptor/filter never gets called.

ProductController.java

@RestController
@RequestMapping("/api")
public class ProductController {

    @Inject
    private ProductService productService;

    //URI: http://localhost:8080/api/products
    @RequestMapping(value = "/products", method = RequestMethod.GET)
    public ResponseEntity<Iterable<Product>> getAllProducts() {
        Iterable<Product> products = productService.getAllProducts();
        return new ResponseEntity<>(products, HttpStatus.OK);
    }

    //URI: http://localhost:8080/api/products/50
    @RequestMapping(value = "/products/{productId}", method = RequestMethod.GET)
    public ResponseEntity<?> getProduct(@PathVariable Long productId) {
        Product product = productService.getProduct(productId);
        return new ResponseEntity<>(product, HttpStatus.OK);
    }

}

SecurityFilter.java

@WebFilter(urlPatterns = {"/api/products/*"})
public class SecurityFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        //in the init method
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        //THIS METHOD NEVER GETS CALLED AND HENCE THIS NEVER GETS PRINTED ON CONSOLE. 
        //WHY ?????
        System.out.println("**********Into the doFilter() method...........");
        final HttpServletRequest httpRequest = (HttpServletRequest) request;
        final HttpServletResponse httpResponse = (HttpServletResponse) response;
        //move ahead
        chain.doFilter(httpRequest, httpResponse);
    }

    @Override
    public void destroy() {
        //nothing to implement
    }

}

BasicRestApplication.java

@SpringBootApplication
public class BasicRestApplication {

    public static void main(String[] args) {
        SpringApplication.run(BasicRestApplication.class, args);
    }

}

I have gone through this link How to add a filter class in Spring Boot? but it does not give a clear idea on what needs to be added where to register the filter with Spring Boot.

Answer 1

Found the solution from here Add a Servlet Filter in a Spring Boot application

Created a new configuration class and registered the filter class.

@Configuration
public class ApplicationConfig {

    @Bean
    public Filter securityFilter() {
        return new SecurityFilter();
    }

}