Unable to autowire the service inside my authentication filter in Spring

Question

I am trying to authenticate user by token, But when i try to auto wire one my services inside the AuthenticationTokenProcessingFilter i get null pointer excepti

Answer 1

It's an old enough question, but I'll add my answer for those who like me google this issue.

You must inherit your filter from GenericFilterBean and mark it as a Spring @Component

@Component
public class MyFilter extends GenericFilterBean {

    @Autowired
    private MyComponent myComponent;

 //implementation

}

And then register it in Spring context:

@Configuration
public class MyFilterConfigurerAdapter extends WebMvcConfigurerAdapter {

    @Autowired
    private MyFilter myFilter;

    @Bean
    public FilterRegistrationBean myFilterRegistrationBean() {
        FilterRegistrationBean regBean = new FilterRegistrationBean();
        regBean.setFilter(myFilter);
        regBean.setOrder(1);
        regBean.addUrlPatterns("/myFilteredURLPattern");

        return regBean;
    }
}

This properly autowires your components in the filter.