org.springframework.validation.BeanPropertyBindingResult: 1 errors Field error in object 'boardDefaultVO' on field 'idx': rejected value [{{idx}}]; codes [typeMismatch.boardDefaultVO.idx,typeMismatch.idx,typeMismatch.int,typeMismatch]; arguments [org.springframework.context.support.DefaultMessageSourceResolvable: codes [boardDefaultVO.idx,idx]; arguments []; default message [idx]]; default message [Failed to convert property value of type 'java.lang.String' to required type 'int' for property 'idx'; nested exception is java.lang.NumberFormatException: For input string: "{{idx}}"]