MailJet Not able to send from java email: ( 400 Bad Request )

Question

I try to send an email from our java project but every time I have a code error 400. So I take the same request printed in the java console and send it from Postman with the same other elements then it works from Postman and i receive the email but from java I have always the code error 400 bad request and when i turn on the Mailjet debug mode the content is null.

Here the final JSON made by Java and inject from Postman

{
    "Messages": [
        {
            "Variables": {
                "objet": " objet",
                "body": " body "
            },
            "From": {
                "Email": "[email protected]"
            },
            "To": [
                {
                    "Email": "[email protected]",
                    "Name": ""
                }
            ],
            "TemplateID": 111111,
            "TemplateLanguage": true,
            "Subject": "[[data:objet:\" anything\"]]"
        }
    ]
}

The java code :

/**
     *  Send a message
     * @return MailjetResponse
     * @throws MailjetException
     * @throws MailjetSocketTimeoutException
     */
    public MailjetRequest sendEmailCore()  {
        return new MailjetRequest(Emailv31.resource)
                .property(Emailv31.MESSAGES, new JSONArray()
                        .put(new JSONObject()
                                .put(Emailv31.Message.FROM, new JSONObject()
                                    .put("Email", senderMail)
                                    .put("Name", senderName))
                                .put(Emailv31.Message.TO, getRecipientsJson())
                                .put(Emailv31.Message.TEMPLATEID, TEMPLATE_ID)
                                .put(Emailv31.Message.TEMPLATELANGUAGE, true)
                                .put(Emailv31.Message.SUBJECT, "[[data:objet:\" anything\"]]")
                                .put(Emailv31.Message.VARIABLES, new JSONObject()
                                                .put("objet", " objet")
                                                       .put("mailTitle", mailTitle)
                                                .put("body", body))));
    }

    private JSONArray getRecipientsJson(){
        JSONArray json = new JSONArray();
        for (String recipient : recipients) {
            json.put(new JSONObject()
                        .put("Email", recipient)
                        .put("Name", ""));
        }
        return json;
    }

    public MailjetResponse sendLoggedMail() throws Exception {
        MailjetClient client = new MailjetClient(API_KEY_PUBLIC, API_KEY_PRIVATE, new ClientOptions("v3.1"));
        MailjetRequest request = sendEmailCore();
        MailjetResponse response = null;
        try {
            client.setDebug(MailjetClient.VERBOSE_DEBUG);
            log.info(request.getBody());
            response = client.post(request);
        }  catch (final MailjetException | MailjetSocketTimeoutException e) {
        
            log.error("sendLoggedMail", e);
        } 
        return response;
    }

The MailJet log :

=== HTTP Request ===
POST https://api.mailjet.com/v3.1/send
Accept-Charset:UTF-8
Accept:application/json
user-agent:mailjet-apiv3-java/v4.5.0
Content-Type:application/json
=== HTTP Response ===
Receive url: https://api.mailjet.com/v3.1/send
Status: 400
date:Tue, 01 Sep 2020 08:59:55 GMT
null:HTTP/1.1 400 Bad Request
content-length:177
x-mj-request-guid:0bb2a0ac-849d-4d80-82ed-a10a792e8d19
content-type:application/json; charset=UTF-8
Content:
null

Thank you for your help.

Answer 1

I have the same issue with Java Mailjet Client 4.5.0. Downgrading to v4.4.0 this error isn't there.

Answer 2

The default value for the connection timeout is too small in version 4.5.0

You can try to set value in client options like this:

new MailjetClient("public", "secret", new ClientOptions(8000));

or just use the newer version, where the default timeout value is set.