我正在play框架中编写一个控制器方法,该方法调用一个返回Future的函数,该函数也可能抛出异常.我无法弄清楚如何捕获和处理该异常.
这是我试过的:
def openIDCallback = Action { implicit request => Async ( Try(OpenID.verifiedId) match { case Failure(thrown) => { PurePromise(Ok("Failed: " + thrown)) } case Success(successResult) => { successResult.map( userInfo => { Ok(userInfo.id + "\n" + userInfo.attributes) }) } } ) }
OpenID.verifiedId是来自Play的OpenId api的函数,它返回Future [UserInfo].这是该函数的来源:
def verifiedId(queryString: Map[String,Seq[String]]): Future[UserInfo] = { (queryString.get("openid.mode").flatMap(_.headOption),queryString.get("openid.claimed_id").flatMap(_.headOption)) match { // The Claimed Identifier. "openid.claimed_id" and "openid.identity" SHALL be either both present or both absent. case (Some("id_res"),Some(id)) => { // MUST perform discovery on the claimedId to resolve the op_endpoint. val server: Future[OpenIDServer] = discovery.discoverServer(id) server.flatMap(directVerification(queryString))(internalContext) } case (Some("cancel"),_) => PurePromise(throw Errors.AUTH_CANCEL) case _ => PurePromise(throw Errors.BAD_RESPONSE) } }
如上所示,函数可以返回PurePromise(抛出Errors.AUTH_CANCEL)和PurePromise(抛出Errors.BAD_RESPONSE).我对解决方案的尝试正确地处理了成功,但是在我获得的异常情况下:
play.api.Application$$anon$1: Execution exception[[AUTH_CANCEL$: null]]
我的问题是如何在我的控制器方法中捕获和处理这些异常?