Posting multipart/form-data messages with Content-Id headers (for cid: tags) in Clojure, using Jersey 1.17.1.

multipart_test.clj

(ns multipart-test
  (:import
    javax.ws.rs.core.MediaType
    com.sun.jersey.api.client.Client
    com.sun.jersey.api.client.ClientResponse
    com.sun.jersey.api.client.config.DefaultClientConfig
    com.sun.jersey.api.client.filter.HTTPBasicAuthFilter
    com.sun.jersey.multipart.FormDataMultiPart
    com.sun.jersey.multipart.file.FileDataBodyPart
    com.sun.jersey.multipart.impl.MultiPartWriter)
  (:require
    [taoensso.timbre :as logging]))

(defn to-s [s]
  (cond
    (coll? s) (clojure.string/join "," s)
    :otherwise (str s)))

(defn multipart-client []
  (let [cc (DefaultClientConfig.)]
    (-> cc (.getClasses) (.add MultiPartWriter))
    (Client/create cc)))

(defn wrap-basic-auth
  "Set up basic auth on the client, if provided"
  [client {:keys [basic-auth] :as req}]
  (if basic-auth
    (doto client
      (.addFilter (HTTPBasicAuthFilter. (first basic-auth) (last basic-auth))))
    client))

(defn wrap-form-multipart
  "Add the form params to the provided form"
  [form {:keys [form-params] :as req}]
  (doseq [[k v] form-params
          :when (not (nil? v))]
    (logging/info k (to-s v))
    (.field form (name k) (to-s v)))
  form)

(defn wrap-attachments
  "Add the attachments to the provided form"
  [form {:keys [attachment] :as req}]
  (doseq [a attachment]
    (do
      (.bodyPart form
                 (FileDataBodyPart. (:name a)
                                    (:content a)
                                    (MediaType/valueOf (:mime-type a))))))
  form)


(defn post-multipart
  "Create a multipart form post to the provide url, with
  the provided basic-auth, form-params, and attachments"
  [url {:keys [basic-auth form-params attachments] :as req}]

  (let [client (wrap-basic-auth (multipart-client) req)
        resource (.resource client url)
        form (-> (FormDataMultiPart.)
                 (wrap-form-multipart req)
                 (wrap-attachments req))]
    (-> resource
        (.type MediaType/MULTIPART_FORM_DATA_TYPE)
        (.post ClientResponse form))))