Java SendGrid电子邮件API，发送电子邮件附件

我使用sendgrid发送电子邮件，使用以下代码工作正常 但它没有依恋

package sendgrid;

import com.sendgrid.Content;
import com.sendgrid.Email;
import com.sendgrid.Mail;
import com.sendgrid.Method;
import com.sendgrid.Request;
import com.sendgrid.Response;
import com.sendgrid.SendGrid;
import java.io.IOException;

public class SendEmail {
    public static void main(String[] args) throws IOException {
    Email from = new Email("test@example.com");
    String subject = "Hello World from the SendGrid Java Library!";

    Email to = new Email("shareef@gmail.com");
    Content content = new Content("text/plain", "Hello, Email!");
    Mail mail = new Mail(from, subject, to, content);

    SendGrid sg = new SendGrid("SG.rIEh84OgQBybYEJcOMie1wd.AZqqdWNYXbOqTarUJcG-iSg0UtHJtCto4oe6tVzn6es");
    Request request = new Request();
    try {

      request.method = Method.POST;
      request.endpoint = "mail/send";
      request.body = mail.build();

      Response response = sg.api(request);
      System.out.println(response.statusCode);
      System.out.println(response.body);
      System.out.println(response.headers);

    } catch (IOException ex) {
      throw ex;
    }
  }

}

但我需要的是发送附件，所以我搜索了github源代码和web文档API，出于某种原因，没有javadocs，但有一个示例，所以我一直在尝试，直到它起作用，我缩小了一些异常和响应代码，起初我得到了禁止的授权，最好是响应202，表示有效且已排队（），这里是我的代码，它发送电子邮件并带有附件，但当您打开附件时，它的大小为零，并表示无法打开或预览文件

 package sendgrid;

    import com.sendgrid.Attachments;
    import com.sendgrid.Content;
    import com.sendgrid.Email;
    import com.sendgrid.Mail;
    import com.sendgrid.MailSettings;
    import com.sendgrid.Method;
    import com.sendgrid.Request;
    import com.sendgrid.SendGrid;
    import com.sendgrid.Setting;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.IOException;


    public class SendEmailAttachmentV2 {

        public static void main(String[] args) throws IOException {
            sendmail();
        }

        // Fully populated Mail object
        public static void sendmail() throws IOException {

            com.sendgrid.Response response1;

            Email from = new Email("shareef@gmail.com");
            String subject = "Hello World from the SendGrid Java Library!";

            Email to = new Email("shareef@gmail.com");
            Content content = new Content("text/plain", "Hello, Email!");
            Mail mail = new Mail(from, subject, to, content);

            File file = new File("C:\\x.png");
            byte[] fileData = null;
            try {
                fileData = org.apache.commons.io.IOUtils.toByteArray(new FileInputStream(file));
            } catch (IOException ex) {
            }

            Attachments attachments3 = new Attachments();            
            attachments3.setContent(new String(fileData, 0, (int) file.length(), "UTF-8"));
            attachments3.setType("image/png");//"application/pdf"
            attachments3.setFilename("x.png");
            attachments3.setDisposition("attachment");
            attachments3.setContentId("Banner");
            mail.addAttachments(attachments3);


            MailSettings mailSettings = new MailSettings();
            Setting sandBoxMode = new Setting();
            sandBoxMode.setEnable(true);
            mailSettings.setSandboxMode(sandBoxMode);

            SendGrid sg = new SendGrid("SG.1Hg78VK0TJ6kexUnByZUYg.LAa5A4GufssZ9lpPQdV6PcZCY6SZ9Xq6LvqfMRG0wesKw");
            Request request1 = new Request();
            try {
                request1.method = Method.POST;
                request1.endpoint = "mail/send";

                request1.body = mail.build();

                response1 = sg.api(request1);
                System.out.println(response1.statusCode);
                System.out.println(response1.body);
                System.out.println(response1.headers);

            } catch (IOException ex) {
                System.out.println(ex);
            }
        }

    }

---

仅供参考：使用从sendgrid控制台生成的API密钥

当我执行代码时，我在netbeans的日志中得到了以下消息

 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}

解决此问题的诀窍是使用commons apache codec及其包中的

encodeAsString

方法对附件进行编码

org.apache.commons.codec.binary.Base64

---

甚至内容长度也被重新运行为0，以响应它起作用了

这是使用SendGrid API发送附件的方式

Mail mail = createEmail();
    Attachments attachments = new Attachments();
    Base64 x = new Base64();
    String encodedString = x.encodeAsString(loadPdfFromClasspath());
    attachments.setContent(encodedString);
    attachments.setDisposition("attachment");
    attachments.setFilename("xyx.pdf");
    attachments.setType("application/pdf");
    mail.addAttachments(attachments);


try {
        request.method = com.sendgrid.Method.POST;
        request.endpoint = "mail/send";
        request.body = mail.build();
        // Uncomment once connectivity with sendgrid is resolved
        Response response = sg.api(request);

}catch (IOException ex) {
        throw ex;
    }

它对我有用（）：

---

您应该从代码中删除密钥示例Yes Thank@IcedDante我已经随机放置了一个不是真实的，我将以任何方式重新随机放置。谢谢，但随电子邮件发送的附件是完整的新表单。在我的例子中，我想发送包含执行结果数据的excel。请告诉我如何从本地系统将文件excel文件作为附件发送。我想它应该是

String attachmentContent=Base64.getEncoder（）.encodeToString（attachmentContentBytes）

而不是

字符串attachmentContent=Base64.getMimeEncoder（）.encodeToString（attachmentContentBytes）@codetriper，当然可以。From“MIME编码器使用基本字母表以MIME友好格式生成Base64编码的输出。输出的每行长度不超过76个字符，并以回车符结尾，后跟换行符（\r\n）”
Mail mail = createEmail();
    Attachments attachments = new Attachments();
    Base64 x = new Base64();
    String encodedString = x.encodeAsString(loadPdfFromClasspath());
    attachments.setContent(encodedString);
    attachments.setDisposition("attachment");
    attachments.setFilename("xyx.pdf");
    attachments.setType("application/pdf");
    mail.addAttachments(attachments);


try {
        request.method = com.sendgrid.Method.POST;
        request.endpoint = "mail/send";
        request.body = mail.build();
        // Uncomment once connectivity with sendgrid is resolved
        Response response = sg.api(request);

}catch (IOException ex) {
        throw ex;
    }

        import com.sendgrid.helpers.mail.objects.Attachments;
        import com.sendgrid.helpers.mail.objects.Content;
        import com.sendgrid.helpers.mail.objects.Email;
        import com.sendgrid.helpers.mail.Mail;

        ......

        Content content = new Content("text/html", body);
        Mail mail = new Mail(from, subject, to, content);
        Path file = Paths.get(filePath);
        Attachments attachments = new Attachments();
        attachments.setFilename(file.getFileName().toString());
        attachments.setType("application/pdf");
        attachments.setDisposition("attachment");

        byte[] attachmentContentBytes = Files.readAllBytes(file);
        String attachmentContent = Base64.getMimeEncoder().encodeToString(attachmentContentBytes);
        attachments.setContent(attachmentContent);
        mail.addAttachments(attachments);

        SendGrid sg = new SendGrid(apiKey);
        Request request = new Request();

        request.setMethod(Method.POST);
        request.setEndpoint("mail/send");
        request.setBody(mail.build());
        Response response = sg.api(request);