SendGrid电子邮件API，发送电子邮件附件

当我执行代码时，我在netbeans的日志中收到以下消息

 202 {X-frame-Options=DENY, Server=nginx, Connection=keep-alive, X-Message-Id=vqVw2RtUShSVQ_ymVEVqaw, Content-Length=0, Date=Tue, 26 Jul 2016 20:05:54 GMT, Content-Type=text/plain; charset=utf-8}

解决此问题的技巧是使用commons apache编解码器commons-
prec-1.8.jar
及其

enpreAsString

org.apache.commons.prec.binary.base64

Attachments attachments3 = new Attachments();base64 x = new base64();String imageDataString = x.enpreAsString(fileData);attachments3.setContent(imageDataString);attachments3.setType("image/png");//"application/pdf"attachments3.setFilename("x.png");attachments3.setDisposition("attachment");attachments3.setContentId("Banner");mail.addAttachments(attachments3);

作为响应 ， 即使content-length也被设置为0 。