Spring Security config autowiring custom UserDetailsService bean

Question

I recently came back to a Spring project I'd been working on and I've run into issues when starting up the app. This question is probably a duplicate, but I haven't been able to find an answer.

Here's a snippet from my original SecurityConfig.java:

@Configuration
@EnableWebSecurity
public class SecurityConfig extends WebSecurityConfigurerAdapter {

    @Autowired private UserService userService;

    /**
     * Global security config to set the user details service etc.
     * @param auth authentication manager
     * @throws Exception
     */
    @Autowired
    public void configureGlobal(AuthenticationManagerBuilder auth) throws Exception {
        auth
                .userDetailsService(userService)
                .passwordEncoder(passwordEncoder());
    }

The UserService object implements UserDetailsService. This gave the error on startup:

Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.clubmate.web.service.UserService com.clubmate.web.config.SecurityConfig.userService; nested exception is java.lang.IllegalArgumentException: Can not set com.clubmate.web.service.UserService field com.clubmate.web.config.SecurityConfig.userService to com.sun.proxy.$Proxy62
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:573)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331)
    ... 58 more
Caused by: java.lang.IllegalArgumentException: Can not set com.clubmate.web.service.UserService field com.clubmate.web.config.SecurityConfig.userService to com.sun.proxy.$Proxy62
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167)
    at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171)
    at sun.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:81)
    at java.lang.reflect.Field.set(Field.java:764)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:569)
    ... 60 more

From my reading, this is because I'm autowiring a concrete class instead of the UserDetailsService interface, but this is strange to me, because when I worked on this project before, autowiring the concrete class worked fine.

I gave in and just changed it to autowire the UserDetailsService interface in SecurityConfig.java.

I'm not sure whether this is related or not, but now on startup I get the below error, for any of my other bean objects (@Services etc.) that have @Autowire private UserService userService.

Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: private com.clubmate.web.service.UserService com.clubmate.web.service.PageService.userService; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.clubmate.web.service.UserService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:573)
    at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331)
    ... 58 more
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type [com.clubmate.web.service.UserService] found for dependency: expected at least 1 bean which qualifies as autowire candidate for this dependency. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoSuchBeanDefinitionException(DefaultListableBeanFactory.java:1373)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1119)
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1014)
    at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:545)
    ... 60 more

Any help greatly appreciated. This has been driving me nuts for hours.

Update

More info: I have another config class (AppConfig.java) with the following:

@Configuration
@EnableWebMvc
@ComponentScan("com.clubmate.web")
@PropertySource(value = { "classpath:application.properties" })
@Import({
        SecurityConfig.class,
        CacheConfig.class,
        DatabaseConfig.class,
        CronConfig.class
})
public class AppConfig extends WebMvcConfigurerAdapter {
    // ...
}

I also have two app initializer classes, one for MVC which is:

public class ServletInitializer extends AbstractAnnotationConfigDispatcherServletInitializer {

    @Override
    public Class<?>[] getRootConfigClasses() {
        return new Class[] {
                AppConfig.class
        };
    }

    @Override
    public Class<?>[] getServletConfigClasses() {
        return new Class[] {
                StartupHousekeeping.class,
                ShutdownHousekeeping.class
        };
    }

    @Override
    public String[] getServletMappings() {
        return new String[] {
                "/"
        };
    }

}

...and another for Security which is:

public class AppInitializer extends AbstractSecurityWebApplicationInitializer {

    private static Logger log = LogManager.getLogger(AppInitializer.class);

    @Override
    protected void beforeSpringSecurityFilterChain(ServletContext context) {
        // load multipart filter before other filters are created
        // see: http://docs.spring.io/spring-security/site/docs/4.0.1.RELEASE/reference/htmlsingle/#csrf-multipart
        MultipartFilter multipartFilter = new MultipartFilter();
        multipartFilter.setMultipartResolverBeanName("multipartResolver");
        insertFilters(context, multipartFilter);
    }

}

Could these be conflicting somehow?

Update 2

Screenshot of where the exception is being thrown: http://i.imgur.com/r6AsOob.jpg

var1 is the SecurityConfig class, var2 is a Proxy object, which should instead be my UserService class.

Answer 1

The autowiring fails because by default Spring creates proxies using JDK-dynamic proxies (which proxies the target class by implementing its interface(s)). CGLIB-based proxies on the other hand are subclasses of the target class.

See: What is the difference between JDK dynamic proxy and CGLib?

To enable CGLIB based proxying annotate one of your @Configuration classes with @EnableAspectJAutoProxy(proxyTargetClass=true):

@Configuration
@EnableAspectJAutoProxy(proxyTargetClass=true)
public class AppConfig {
    ...
}

Note that as of version 3.2 CGLIB is repackaged and included in the spring-core JAR. Therefore it will work right out of the box.

Answer 2

Thanks to @fateddy in the comments, the solution was to add

@EnableAspectJAutoProxy(proxyTargetClass=true)

to my AppConfig class, and then import the org.aspectj libraries to my project.