Can not set field to com.sun.proxy.$Proxy
Solution 1
Can not set 'FileValidator' field 'FileController.validator' to 'com.sun.proxy.$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.
Solution 2
Autowire the interface of FileValidator(class)
in your class FileController
.
Doing this will not require you to specify @Qualifier as mentioned below:
@Autowired
IFileValidator filevalidator;
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FunnyJava
Updated on March 29, 2020Comments
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FunnyJava over 3 years
For file upload I am trying to inject and use a Validator in my Spring Controller like this:
@RestController @RequestMapping("/api") public class FileController{ @Autowired private MessageSource messageSource; @Autowired FileValidator validator; @InitBinder("file") public void initBinderFile(WebDataBinder binder) { binder.setValidator(validator); } @RequestMapping(value = "/fileUpload2", method = RequestMethod.POST, produces = {"text/plain"}) @PreAuthorize("hasAuthority('ADMINISTRATOR')") public String singleFileUpload2(@Valid @ModelAttribute("file") File file, BindingResult result) throws IOException { if (result.hasErrors()) { String errorString = ""; for (ObjectError error : result.getAllErrors()) { errorString = errorString.concat(messageSource.getMessage(error.getCode(), new String[]{}, Locale.ENGLISH)+"\n"); } return errorString; } else { MultipartFile multipartFile = file.getFile(); String fileName = multipartFile.getOriginalFilename(); System.out.println("Fetching file: "+fileName); return messageSource.getMessage("upload.file.success", new String[]{}, Locale.ENGLISH); } } }
Here is my Validator:
@Component public class FileValidator implements Validator { @Override public boolean supports(Class<?> clazz) { return File.class.isAssignableFrom(clazz); } @Override public void validate(Object obj, Errors errors) { File file = (File) obj; if (file.getFile().getSize() == 0) { errors.rejectValue("file", "missing.file"); } else try { if (file.getFile().getBytes().length > 2097152l) { errors.rejectValue("file", "upload.file.error.size"); } if(!file.getFile().getContentType().equalsIgnoreCase("text/html")){ errors.rejectValue("file", "incorrect.file.type"); } } catch (IOException ex) { errors.rejectValue("file", "upload.file.error"); } } }
Here is the File object that I am trying to validate:
public class File { private String name; private MultipartFile file; public File() { } public File(MultipartFile file) { this.file = file; } public String getName() { return name; } public void setName(String name) { this.name = name; } public MultipartFile getFile() { return file; } public void setFile(MultipartFile file) { this.file = file; } }
And here is the error that I get when I try to start my application:
org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'fileController': Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.enterprise.springapp.web.validators.FileValidator com.eurodyn.springapp.web.FileController.validator; nested exception is java.lang.IllegalArgumentException: Can not set com.enterprise.springapp.web.validators.FileValidator field com.enterprise.springapp.web.FileController.validator to com.sun.proxy.$Proxy101 at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:334) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.populateBean(AbstractAutowireCapableBeanFactory.java:1214) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean(AbstractAutowireCapableBeanFactory.java:543) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean(AbstractAutowireCapableBeanFactory.java:482) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory$1.getObject(AbstractBeanFactory.java:306) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton(DefaultSingletonBeanRegistry.java:230) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean(AbstractBeanFactory.java:302) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.support.AbstractBeanFactory.getBean(AbstractBeanFactory.java:197) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:772) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:839) ~[spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:538) ~[spring-context-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118) ~[spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE] at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:766) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE] at org.springframework.boot.SpringApplication.createAndRefreshContext(SpringApplication.java:361) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:307) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1191) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE] at org.springframework.boot.SpringApplication.run(SpringApplication.java:1180) [spring-boot-1.3.5.RELEASE.jar:1.3.5.RELEASE] at com.enterprise.springapp.SpringApp.main(SpringApp.java:30) [classes/:na] Caused by: org.springframework.beans.factory.BeanCreationException: Could not autowire field: com.enterprise.springapp.web.validators.FileValidator com.enterprise.springapp.web.FileController.validator; nested exception is java.lang.IllegalArgumentException: Can not set com.enterprise.springapp.web.validators.FileValidator field com.enterprise.springapp.web.FileController.validator to com.sun.proxy.$Proxy101 at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:573) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.annotation.InjectionMetadata.inject(InjectionMetadata.java:88) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor.postProcessPropertyValues(AutowiredAnnotationBeanPostProcessor.java:331) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] ... 17 common frames omitted Caused by: java.lang.IllegalArgumentException: Can not set com.enterprise.springapp.web.validators.FileValidator field com.enterprise.springapp.web.FileController.validator to com.sun.proxy.$Proxy101 at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167) ~[na:1.8.0_45] at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171) ~[na:1.8.0_45] at sun.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:81) ~[na:1.8.0_45] at java.lang.reflect.Field.set(Field.java:764) ~[na:1.8.0_45] at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:569) ~[spring-beans-4.2.6.RELEASE.jar:4.2.6.RELEASE] ... 19 common frames omitted 2016-06-09 15:12:39.909 WARN 4896 --- [ main] o.s.boot.SpringApplication : Error handling failed (Error creating bean with name 'delegatingApplicationListener' defined in class path resource [org/springframework/security/config/annotation/web/configuration/WebSecurityConfiguration.class]: BeanPostProcessor before instantiation of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.transaction.annotation.ProxyTransactionManagementConfiguration': Initialization of bean failed; nested exception is org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'org.springframework.context.annotation.ConfigurationClassPostProcessor.importRegistry' is defined)
I don't know what's happening. Can anyone help?
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a better oliver over 7 years1. Never use
@Autowired
on fields. 2. There is a configuration for web security so it doesn't make much sense to put@PreAuthorize("hasAuthority('ADMINISTRATOR')")
on a controller method. The combination of that two points is the cause of your problem.
-
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FunnyJava over 7 yearsThank you very much for your help! I applied the 2nd solution and it worked.
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a better oliver over 7 yearsThe problem is not
FileValidator
butFileController
. -
OrangeDog over 7 years@zeroflagL the problem is how they are interacting - it's not just one or the other.
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a better oliver over 7 yearsNo. Spring tries to create a proxy for
FileController
and then cannot set thevalidator
. The error message cannot be more explicit. -
OrangeDog over 7 years@zeroflagL The
$Proxy101
refers to the proxy of aFileValidator
bean, which cannot be assigned to aFileValidator
-typed field because it implementsValidator
instead of extendingFileValidator
. -
a better oliver over 7 yearsWhy should there be a proxy for
FileValidator
? -
OrangeDog over 7 yearsWhy is it trying to assign a proxy to
FileController.validator
? -
OrangeDog over 7 yearsAnyway, regardless whether either or both of the classes would need re-factoring, the solution of enabling class-proxies will always work.