Spring Boot服务注入到doFiler

Question

I am trying to inject a auth service to a Filter -

@Autowired
AuthRequestService authService;

And use it in doFiler method -

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
        throws IOException, ServletException {
    HttpServletRequest req = (HttpServletRequest) request;
    System.out.println("SAPServiceFilter: "+ req.getRequestURI());
    //TODO - create auth sender
    authService.isAuthnticate((HttpServletRequest)request); //null
    chain.doFilter(request, response);
}

My filter class in sub-package of my @SpringBootApplication class and annotated with @service -

@Service
public class AuthRequestService {

    @PostConstruct
    public void init() {
        System.out.println("AuthRequestService @PostConstruct");
    }

    public boolean isAuthnticate(HttpServletRequest request) {
        System.out.println("isAuthnticate");
        return true;
    }
}

The class also appears when listing all my beans using -

for (String name : applicationContext.getBeanDefinitionNames()) {
    System.out.println(name);
}

Still when debugging authService is null, one last thing the filter is registered with FilterRegistrationBean -

FilterRegistrationBean<SAPServiceFilter> filterRegBean = new FilterRegistrationBean<>();
filterRegBean.setFilter(new SAPServiceFilter());

Answer 1

You could use constructor injection. Supposed your filter registration bean lives in a component and has access to the service you could autowire it there and pass it with the constructor

@Autowired  
AuthRequestService authRequestService;

[...]

FilterRegistrationBean<SAPServiceFilter> filterRegBean = new FilterRegistrationBean<>();
filterRegBean.setFilter(new SAPServiceFilter(authRequestService));

Answer 2

Your filter is not under the control of spring. That´s why the autowired dependencies are not being injected.

In your filter init code add this line:

SpringBeanAutowiringSupport.processInjectionBasedOnCurrentContext(this);

or

SpringBeanAutowiringSupport.processInjectionBasedOnServletContext(this,getServletContext());

But there are more other ways to register a servlet filter in spring context: https://docs.spring.io/spring-boot/docs/current/reference/htmlsingle/#boot-features-embedded-container-servlets-filters-listeners-beans