We can not find rest API for attachment.

We are unable to find any solution in the above link

Hi pratikgadekar,

the field parameter name to post a message with restapi is "message.upload".

here is my Java sample code to post a message with an an attachment via REST API. (you may need to import the latest apache http jar files)

    public static void main(String[] args) throws Exception {

        // Setup
        String communityUrl = "http://mycommunityid.stage.lithium.com";
        String restUser = "HaidongG";
        String restPassword = "my_secret_password";

        String communityRestUrl = communityUrl + "/restapi/vc";

        debug("Authentication ...");
        String loginUrl = communityRestUrl + "/authentication/sessions/login?user.login=" + restUser + "&user.password=" + restPassword;
        String authenResult = httpGet(loginUrl, null);
        String restSessionKey = extractSessionKeyFromXML(authenResult);

        String board = "this_is_my_board_id";
        String subject = encode("Subject 9th April");
        String body = encode("Body 9th April");

        debug("creating Message with attachment");
        String postUrl = communityRestUrl + "/boards/id/" + board + "/messages/post";
        String createResult = httpPostMessage(postUrl, restSessionKey, subject, body, new File("c:/tmp/test.jpg"));
        String messageId = extractMessageIdFromXML(createResult);
        debug("\n\n messageId=" + messageId + "\n\n");
    }
    
    private static String httpPostMessage(String urlStr, String restSessionKey, String subject, String body, File file) throws Exception {

        urlStr = addSessionKeyToURL(urlStr, restSessionKey);
        debug("Posting to " + urlStr + ", Attachment is " + file.getAbsolutePath());

        HttpPost post = new HttpPost(urlStr);
        MultipartEntityBuilder builder = MultipartEntityBuilder.create();

        builder.addTextBody("message.subject", subject);
        builder.addTextBody("message.body", body);        
        builder.addPart("message.upload", new FileBody(file));

        HttpEntity entity = builder.build();
        post.setEntity(entity);
        HttpClient client = HttpClientBuilder.create().build();
        HttpResponse response = null;
        try {
            response = client.execute(post);
        } catch (ClientProtocolException e) {
            debug(e);
        } catch (IOException e) {
            debug(e);
        }

        return getResponseString(response);
    }

 I hope that my code helps to explain better.

Best Regards

Haidong