SendGrid sent new copy of attachment instead of local file

I want to send dynamically generated excel file programmatically using sendgrid function. Below java program is sending the excel file as an attachment successfully, But It is sending fresh copy (newly generated) of excel file not a file which I like to send. Please let me know Where do I am making mistake ?

public static void main(String[] args) throws IOException, InvalidFormatException {

    final String path = "C:\\Users\\src\\testData\\TestData.xlsx";

    byte[] bFile = Files.readAllBytes(new File(path).toPath());

    Attachments attachments3 = new Attachments();
    Base64 x = new Base64();
    String imageDataString = x.encodeAsString(bFile);
    attachments3.setContent(imageDataString);
    attachments3.setType("xlxs");// "application/pdf"
    attachments3.setFilename("TestData.xlsx");
    attachments3.setDisposition("attachment");
    attachments3.setContentId("Banner");

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

    Email to = new Email("sachin@test.com");
    Content content = new Content("text/plain", "Hello, Email!");
    Mail mail = new Mail(from, subject, to, content);
    mail.addAttachments(attachments3);

    SendGrid sg = new SendGrid("SG.EJLRKZEvE");
    Request request = new Request();
    try {

        request.setMethod(Method.POST);
        request.setEndpoint("mail/send");
        request.setBody(mail.build());

        Response response = sg.api(request);
        System.out.println(response.getStatusCode());
        System.out.println(response.getBody());
        System.out.println(response.getHeaders());

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

I wrote the following test class and successfully sent/received an email with an excel attachment with content. The code is same as yours, other than the type set in the attachment object. Pasting the whole class here so that you can check the imports too. I am using sendgrid-java version 4.3.0. Make sure to move to the 4.3.0 version before you test this code. I have also truncated my api-key below so replace it with your api-key.

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;

import org.apache.commons.codec.binary.Base64;

import com.sendgrid.Attachments;
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;

public class TestSGEmail {
  public static void main(String args[]) {

    final String path = "/Users/macuser/testxls.xlsx";

    byte[] bFile = null;
    try {
      bFile = Files.readAllBytes(new File(path).toPath());
    } catch (IOException e) {
      e.printStackTrace();
    }

    Attachments attachments3 = new Attachments();
    Base64 x = new Base64();
    String imageDataString = x.encodeAsString(bFile);
    attachments3.setContent(imageDataString);
    attachments3.setType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
    attachments3.setFilename("TestData.xlsx");
    attachments3.setDisposition("attachment");
    attachments3.setContentId("Banner");

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

    Email to = new Email("myemail@example.com");

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

    mail.addAttachments(attachments3);

    SendGrid sg = new SendGrid("SG.tGX184I");

    Request request = new Request();
    try {
      request.setMethod(Method.POST);
      request.setEndpoint("mail/send");
      request.setBody(mail.build());

      Response response = sg.api(request);
      System.out.println(response.getStatusCode());
      System.out.println(response.getBody());
      System.out.println(response.getHeaders());

    } catch (IOException ex) {
      ex.printStackTrace();
    }
  }
}

Hope this helps!