[Spring-boot File Upload]The temporary upload location ... is not valid

报错信息：

"localizedMessage": "The temporary upload location [C:\\Users\\YY\\AppData\\Local\\Temp\\tomcat.1793760262133383655.8081\\work\\Tomcat\\localhost\\ROOT] is not valid",
"message": "The temporary upload location [C:\\Users\\YY\\AppData\\Local\\Temp\\tomcat.1793760262133383655.8081\\work\\Tomcat\\localhost\\ROOT] is not valid",
"suppressed": []

import org.springframework.boot.web.servlet.MultipartConfigFactory;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.servlet.MultipartConfigElement;
import java.io.File;
/**
 * 配置文件上传临时路径，解决上传报错的问题
 * localizedMessage:
 * "The temporary upload location
 * [C:\Users\YY\AppData\Local\Temp\tomcat.3305898259059649641.8083\work\Tomcat\localhost\ROOT]
 * is not valid"
 */
@Configuration
public class MultipartConfig {
    /**
     * 文件上传临时路径
     */
    @Bean
    MultipartConfigElement multipartConfigElement() {
        MultipartConfigFactory factory = new MultipartConfigFactory();
        String location = System.getProperty("user.dir") + "/data/tmp";
        File tmpFile = new File(location);
        if (!tmpFile.exists()) {
            tmpFile.mkdirs();
        }
        factory.setLocation(location);
        return factory.createMultipartConfig();
    }
}