yokogiri.clj

(defn write-file [filename file]
  (with-open [w (clojure.java.io/output-stream filename)]
    (.write w (:body file))))

(let [base-uri "http://google.com"
      img-path (-> (get-page base-uri)
                   (first-by-xpath "//img[@alt='Google']")
                   (comp :src attrs))
      img-url (str base-uri img-path)]
  (->> (clj-http.client/get img-uri {:as :byte-array
                                     :follow-redirects true})
       (write-file "google-homepage.png")))