Spring boot 文件上传大小限制问题

在application.properties中设置文件大小
spring.servlet.multipart.max-file-size=30MB
spring.servlet.multipart.max-request-size=30MB

启动时产生错误：
Failed to bind properties under ‘spring.servlet.multipart.max-file-size’ to org.springframework.util.unit.DataSize:

Property: spring.servlet.multipart.max-file-size
Value: 30MB  
Origin: class path resource [application.properties]:10:40
Reason: failed to convert java.lang.String to org.springframework.util.unit.DataSize  

解决方法
在在启动类Application.class文件中配置Bean来设置文件大小
@SpringBootApplication
@Configuration
public class WxApplication{

public static void main(String[] args) {
    SpringApplication.run(WxApplication.class, args);
}

@Bean
public MultipartConfigElement multipartConfigElement() {
    MultipartConfigFactory factory = new MultipartConfigFactory();
    //单个文件最大
    factory.setMaxFileSize(DataSize.ofMegabytes(30));
    //该方法已降级
    //factory.setMaxRequestSize("30MB");
    /// 设置总上传数据总大小
    factory.setMaxRequestSize(DataSize.ofMegabytes(120));
    return factory.createMultipartConfig();
}

}