Google api:将credentialBuilder转换为httprequestInitializer

Question

我试图访问谷歌分析数据，但不断得到ClassCastException在我的credentialBuilder。下面是我的代码:

(defn credential
  []
  (doto (GoogleCredential$Builder.)
    (.setTransport http-transport)
    (.setJsonFactory json-factory)
    (.setServiceAccountId "X")
    (.setServiceAccountPrivateKeyFromP12File (File. "X"))
    (.setServiceAccountScopes (AnalyticsReportingScopes/ANALYTICS_READONLY))
    (.build)))
(defn analytics
  []
  (doto (AnalyticsReporting$Builder. http-transport json-factory (credential))
    (.setApplicationName "X")
    (.build)))

我得到的确切错误是:

com.google.api.client.googleapis.auth.oauth2。GoogleCredential$Builder不能强制转换为com.google.api.client.http.HttpRequestInitializer

我尝试遵循Hello分析报告API V4: Java快速启动服务帐户的例子，我做错了什么?

Answer 1

doto返回作为其第一个参数传递的对象-在您的情况下，它将返回GoogleCredential$Builder的实例并忽略(.build)调用的结果。您需要将其更改为将调用的结果返回给(.build):

(defn credential
  []
  (->
    (doto (GoogleCredential$Builder.)
      (.setTransport http-transport)
      (.setJsonFactory json-factory)
      (.setServiceAccountId "X")
      (.setServiceAccountPrivateKeyFromP12File (File. "X"))
      (.setServiceAccountScopes (AnalyticsReportingScopes/ANALYTICS_READONLY)))
    (.build))

doto被宏展开为如下形式:

(doto (StringBuilder.)
  (.append "a")
  (.append "b"))

是

(let [obj (StringBuilder.)]
  (.append obj "a")
  (.append obj "b")
  obj)