最后，我的解决方案是像这样使用ProcessBuilder：
(defn create-process-builder [js-engine] (doto (ProcessBuilder. ["node" (:path js-engine) "--port-file" (:port-file js-engine) "--default-ajax-host" (:default-ajax-host js-engine) "--default-ajax-port" (str (:default-ajax-port js-engine))]) .inheritIO))
然后在其中调用start。initializeIO使它的输出转到当前进程的输出，该进程有效地合并了stdout和stderr。
最重要的是，NodeJS通过指定0作为端口号来打开随机端口，并将其写入文件：
(let [app (-> (express) (.use (cookie-parser)) (.get "/" (fn [_req res] (.send res "Universal Javascript engine for server side pre-rendering single page applications."))) (.get "/render" render)) server (.createServer http app)] (.listen server 0 (fn [] (.writeFile fs (:port-file options) (.-port (.address server)))))))))
然后由Java端打开（等待它出现）：
(defn get-port-number [js-engine] (or (with-timeout (:start-timeout js-engine) (loop [port-number (read-port-file js-engine)] (if (string/blank? port-number) (if (is-running? js-engine) (do (Thread/sleep 100) (recur (read-port-file js-engine))) (throw (Exception. (str "While waiting for port number, process died: " (:path js-engine))))) port-number))) (throw (Exception. (str "Waited for " (:start-timeout js-engine) " for " (:path js-engine) " to start and report its port number but it timed out.")))))
