Follow-redirect support

4 files changed, 53 insertions, 4 deletions

diff --git a/core/src/main/scala/com/softwaremill/sttp/HttpURLConnectionHandler.scala b/core/src/main/scala/com/softwaremill/sttp/HttpURLConnectionHandler.scala
index 76d897b..548dd9b 100644
--- a/core/src/main/scala/com/softwaremill/sttp/HttpURLConnectionHandler.scala
+++ b/core/src/main/scala/com/softwaremill/sttp/HttpURLConnectionHandler.scala
@@ -13,13 +13,16 @@ import scala.io.Source
 import scala.collection.JavaConverters._
 
 object HttpURLConnectionHandler extends SttpHandler[Id, Nothing] {
-  override def send[T](r: Request[T, Nothing]): Response[T] = {
+  override protected def doSend[T](r: Request[T, Nothing]): Response[T] = {
     val c =
       new URL(r.uri.toString).openConnection().asInstanceOf[HttpURLConnection]
     c.setRequestMethod(r.method.m)
     r.headers.foreach { case (k, v) => c.setRequestProperty(k, v) }
     c.setDoInput(true)
 
+    // redirects are handled in SttpHandler
+    c.setInstanceFollowRedirects(false)
+
     if (r.body != NoBody) {
       c.setDoOutput(true)
       // we need to take care to:
diff --git a/core/src/main/scala/com/softwaremill/sttp/RequestT.scala b/core/src/main/scala/com/softwaremill/sttp/RequestT.scala
index 5e4d33e..95dc56b 100644
--- a/core/src/main/scala/com/softwaremill/sttp/RequestT.scala
+++ b/core/src/main/scala/com/softwaremill/sttp/RequestT.scala
@@ -31,7 +31,8 @@ case class RequestT[U[_], T, +S](
     uri: U[Uri],
     body: RequestBody[S],
     headers: Seq[(String, String)],
-    response: ResponseAs[T, S]
+    response: ResponseAs[T, S],
+    options: RequestOptions
 ) {
   def get(uri: Uri): Request[T, S] =
     this.copy[Id, T, S](uri = uri, method = Method.GET)
@@ -218,6 +219,9 @@ case class RequestT[U[_], T, +S](
   def mapResponse[T2](f: T => T2): RequestT[U, T2, S] =
     this.copy(response = response.map(f))
 
+  def followRedirects(fr: Boolean): RequestT[U, T, S] =
+    this.copy(options = options.copy(followRedirects = fr))
+
   def send[R[_]]()(implicit handler: SttpHandler[R, S],
                    isIdInRequest: IsIdInRequest[U]): R[Response[T]] = {
     // we could avoid the asInstanceOf by creating an artificial copy
@@ -268,3 +272,5 @@ class SpecifyAuthScheme[U[_], T, +S](hn: String, rt: RequestT[U, T, S]) {
   def bearer(token: String): RequestT[U, T, S] =
     rt.header(hn, s"Bearer $token")
 }
+
+case class RequestOptions(followRedirects: Boolean)
diff --git a/core/src/main/scala/com/softwaremill/sttp/SttpHandler.scala b/core/src/main/scala/com/softwaremill/sttp/SttpHandler.scala
index c6df151..fd836bd 100644
--- a/core/src/main/scala/com/softwaremill/sttp/SttpHandler.scala
+++ b/core/src/main/scala/com/softwaremill/sttp/SttpHandler.scala
@@ -1,5 +1,7 @@
 package com.softwaremill.sttp
 
+import java.net.URI
+
 import scala.language.higherKinds
 
 /**
@@ -9,9 +11,41 @@ import scala.language.higherKinds
   *           if streaming requests/responses is not supported by this handler.
   */
 trait SttpHandler[R[_], -S] {
-  def send[T](request: Request[T, S]): R[Response[T]]
+  def send[T](request: Request[T, S]): R[Response[T]] = {
+    val resp = doSend(request)
+    if (request.options.followRedirects) {
+      responseMonad.flatMap(resp, { response: Response[T] =>
+        if (response.isRedirect) {
+          followRedirect(request, response)
+        } else {
+          responseMonad.unit(response)
+        }
+      })
+    } else {
+      resp
+    }
+  }
+
+  private def followRedirect[T](request: Request[T, S],
+                                response: Response[T]): R[Response[T]] = {
+    def isRelative(uri: String) = !uri.contains("://")
+
+    response.header(LocationHeader).fold(responseMonad.unit(response)) { loc =>
+      val uri = if (isRelative(loc)) {
+        // using java's URI to resolve a relative URI
+        uri"${new URI(request.uri.toString).resolve(loc).toString}"
+      } else {
+        uri"$loc"
+      }
+
+      send(request.copy[Id, T, S](uri = uri))
+    }
+  }
+
   def close(): Unit = {}
 
+  protected def doSend[T](request: Request[T, S]): R[Response[T]]
+
   /**
     * The monad in which the responses are wrapped. Allows writing wrapper
     * handlers, which map/flatMap over the return value of [[send]].
diff --git a/core/src/main/scala/com/softwaremill/sttp/package.scala b/core/src/main/scala/com/softwaremill/sttp/package.scala
index a0a6c57..3c4e844 100644
--- a/core/src/main/scala/com/softwaremill/sttp/package.scala
+++ b/core/src/main/scala/com/softwaremill/sttp/package.scala
@@ -37,6 +37,7 @@ package object sttp {
   private[sttp] val AcceptEncodingHeader = "Accept-Encoding"
   private[sttp] val ContentEncodingHeader = "Content-Encoding"
   private[sttp] val ContentDispositionHeader = "Content-Disposition"
+  private[sttp] val LocationHeader = "Location"
   private[sttp] val Utf8 = "utf-8"
   private[sttp] val Iso88591 = "iso-8859-1"
   private[sttp] val CrLf = "\r\n"
@@ -54,7 +55,12 @@ package object sttp {
     * An empty request with no headers.
     */
   val emptyRequest: RequestT[Empty, String, Nothing] =
-    RequestT[Empty, String, Nothing](None, None, NoBody, Vector(), asString)
+    RequestT[Empty, String, Nothing](None,
+                                     None,
+                                     NoBody,
+                                     Vector(),
+                                     asString,
+                                     RequestOptions(followRedirects = true))
 
   /**
     * A starting request, with the following modifications comparing to