在Monix中处理任务中的错误

Question

我有下面的代码片段，它可以通过HTTP简单地查找一组URL。

def parse(filter: ParserFilter): Task[Seq[HttpBinaryResponse]] = {
import scalaj.http._
// Extracts all HTML body anchor elements into an Option
val browser = new JsoupBrowser {
override def requestSettings(conn: Connection): Connection =
conn.timeout(2000)
}
val hrefs =
browser.get(filter.url) >> elementList("a[href]") >?> attr("href")
val batched = hrefs.distinct.flatten
.filter(_.startsWith("http"))
//.map(toTask)
.map(href =>
Task {
HttpBinaryResponse.asHttpBinaryResponse(href, Http(href).asString)
})
.sliding(30, 30)
.toSeq
.map(chunk => Task.parSequence(chunk))
Task.sequence(batched).map(_.flatten)
}

我有一个Play控制器，我在那里调用这个函数并运行任务，如下所示：

val batches = appBindings.httpService.parse(parserFilter)
batches.runToFuture.materialize.map {
case Success(elems) =>
Ok(Json.prettyPrint(Json.obj(
"baseURL" -> s"${parserFilter.url}",
"Total Elements" -> s"${elems.size}",
"results" -> HttpBinaryResponse.asJson(elems)
))).enableCors
case Failure(err) =>
Ok(Json.obj("status" -> "error", "message" -> s"${err.getMessage}")).enableCors
}

对于一个导致SSLHandshakeException的URL，我会进入Failure(err(case块，但我想得到以下内容：

1. 无论错误是什么，我都希望进入成功块，在那里我已经捕获了任何失败URL的错误消息

如何调整我的任务实现以满足我的需求？有什么想法吗？我尝试了onErrorRecoverWith处理程序，但似乎没有任何效果。有什么想法吗？

Answer 1

我成功地完成了以下任务：

def parse(filter: ParserFilter): Task[Seq[HttpBinaryResponse]] = {
import scalaj.http._
// Extracts all HTML body anchor elements into an Option
val browser = new JsoupBrowser {
override def requestSettings(conn: Connection): Connection =
conn.timeout(2000)
}
val hrefs =
browser.get(filter.url) >> elementList("a[href]") >?> attr("href")
val batched = hrefs.distinct.flatten
.filter(_.startsWith("http"))
//.map(toTask)
.map(href =>
Task {
HttpBinaryResponse.asHttpBinaryResponse(href, Http(href).asString)
}.onErrorRecoverWith { case ex: Exception =>
Task.now(
HttpBinaryResponse(
origin = href,
isSuccess = false,
errorMessage = Some(s"${ex.getMessage}")))
})
.sliding(30, 30)
.toSeq
.map(chunk => Task.parSequence(chunk))
Task.sequence(batched).map(_.flatten)
}