[Spring] method="post", method="get"

심각: Servlet.service() for servlet [appServlet] in context with path [/myspring] threw exception[Request processing failed;

nested exception is org.springframework.validation.BindException: org.springframework.validation.BeanPropertyBindingResult: 3 errors

Field error in object 'multiFileBucket' on field 'files[0].file': rejected value [1.xlsx];

codes [typeMismatch.multiFileBucket.files[0].file,typeMismatch.multiFileBucket.files.file,typeMismatch.files[0].file,typeMismatch.files.file,typeMismatch.file,typeMismatch.org.springframework.web.multipart.MultipartFile,typeMismatch];

arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [multiFileBucket.files[0].file,files[0].file]; arguments [];

default message [files[0].file]]; default message [Failed to convert property value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile' for property 'files[0].file';

nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.MultipartFile] for property 'file': no matching editors or conversion strategy found]

String을 변환을 못한다는 의미인듯.. 학원에선 잘됐는데 안되는 원인이 뭔지 잘 모르겠다 ㅜㅜ

Field error in object 'multiFileBucket' on field 'files[1].file': rejected value []; codes [typeMismatch.multiFileBucket.files[1].file,typeMismatch.multiFileBucket.files.file,typeMismatch.files[1].file,typeMismatch.files.file,typeMismatch.file,typeMismatch.org.springframework.web.multipart.MultipartFile,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [multiFileBucket.files[1].file,files[1].file]; arguments []; default message [files[1].file]]; default message [Failed to convert property value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile' for property 'files[1].file'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.MultipartFile] for property 'file': no matching editors or conversion strategy found]

Field error in object 'multiFileBucket' on field 'files[2].file': rejected value []; codes [typeMismatch.multiFileBucket.files[2].file,typeMismatch.multiFileBucket.files.file,typeMismatch.files[2].file,typeMismatch.files.file,typeMismatch.file,typeMismatch.org.springframework.web.multipart.MultipartFile,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [multiFileBucket.files[2].file,files[2].file]; arguments []; default message [files[2].file]]; default message [Failed to convert property value of type 'java.lang.String' to required type 'org.springframework.web.multipart.MultipartFile' for property 'files[2].file'; nested exception is java.lang.IllegalStateException: Cannot convert value of type [java.lang.String] to required type [org.springframework.web.multipart.MultipartFile] for property 'file': no matching editors or conversion strategy found]] with root cause