Can not set field to com.sun.proxy.$Proxy

Question

For file upload I am trying to inject and use a Validator in my Spring Controller like this:

@RestController
@RequestMapping(\"/api\")
public class FileControlle         


        

Answer 1

Can not set 'FileValidator' field 'FileController.validator' to 'com.sun.proxy.$Proxy101'

FileValidator is a class, not an interface.

com.sun.proxy.$Proxy101 is an interface proxy, not a class proxy.

There are two main ways to solve this. Either inject the validator via an interface, e.g:

@Autowired @Qualifier("fileValidator")
private Validator fileValidator;

or enable class-proxies, e.g:

@SpringBootApplication
@EnableAspectJAutoProxy(proxyTargetClass = true)
public class Application {

Those are just examples, there will be other ways to implement those two solutions.