Springboot version: 2.3.0.release

Front end use   File upload with unityengine.wwwform

Service error:

org.springframework.web.multipart.MultipartException: Failed to parse multipart servlet request; nested exception is java.lang.NoClassDefFoundError: javax/mail/internet/MimeUtility

Positioning questions:

POM file import dependency

        <dependency>
            <groupId>javax.mail</groupId>
            <artifactId>mail</artifactId>
            <version>1.4.7</version>
        </dependency>

Re run and solve the problem (* ^ ▽ ^ *)~~