[KTOR-6886] Android Http Client using Android's HttpEngine on API 34+

ktor-client/ktor-client-android/api/ktor-client-android.api

@@ -14,10 +14,14 @@ public final class io/ktor/client/engine/android/AndroidClientEngine : io/ktor/c
 public final class io/ktor/client/engine/android/AndroidEngineConfig : io/ktor/client/engine/HttpClientEngineConfig {
 	public fun <init> ()V
 	public final fun getConnectTimeout ()I
+	public final fun getContext ()Landroid/content/Context;
+	public final fun getHttpEngineConfig ()Lkotlin/jvm/functions/Function1;
 	public final fun getRequestConfig ()Lkotlin/jvm/functions/Function1;
 	public final fun getSocketTimeout ()I
 	public final fun getSslManager ()Lkotlin/jvm/functions/Function1;
 	public final fun setConnectTimeout (I)V
+	public final fun setContext (Landroid/content/Context;)V
+	public final fun setHttpEngineConfig (Lkotlin/jvm/functions/Function1;)V
 	public final fun setRequestConfig (Lkotlin/jvm/functions/Function1;)V
 	public final fun setSocketTimeout (I)V
 	public final fun setSslManager (Lkotlin/jvm/functions/Function1;)V

ktor-client/ktor-client-android/build.gradle.kts

@@ -4,13 +4,15 @@ kotlin.sourceSets {
     jvmMain {
         dependencies {
             api(project(":ktor-client:ktor-client-core"))
+            compileOnly("org.robolectric:android-all:14-robolectric-10818077")
         }
     }
     jvmTest {
         dependencies {
             api(project(":ktor-client:ktor-client-tests"))
             api(project(":ktor-network:ktor-network-tls"))
             api(project(":ktor-network:ktor-network-tls:ktor-network-tls-certificates"))
+            implementation("org.robolectric:android-all:14-robolectric-10818077")
         }
     }
 }

ktor-client/ktor-client-android/jvm/androidTest/io/ktor/client/engine/android/AndroidEngineTest.kt

@@ -0,0 +1,67 @@
+/*
+* Copyright 2014-2021 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+*/
+
+package io.ktor.client.engine.android
+
+import android.net.http.ConnectionMigrationOptions
+import android.net.http.HttpEngine
+import androidx.test.platform.app.InstrumentationRegistry
+import io.ktor.client.HttpClient
+import io.ktor.client.request.get
+import io.ktor.client.statement.bodyAsText
+import kotlinx.coroutines.test.runTest
+import org.junit.Test
+import kotlin.test.assertContains
+
+class AndroidEngineTest {
+    @Test
+    fun testHttpEngine() = runTest {
+        val client = HttpClient(Android.create {
+            httpEngineDisabled = false
+            context = InstrumentationRegistry.getInstrumentation().targetContext
+        })
+
+        val response = client.get("https://github.com/robots.txt")
+
+        assertContains(response.bodyAsText(), "Disallow")
+    }
+    @Test
+    fun testHttpEngineConfig() = runTest {
+        val client = HttpClient(Android.create {
+            httpEngineDisabled = false
+            context = InstrumentationRegistry.getInstrumentation().targetContext
+
+            httpEngineConfig = {
+                setUserAgent("Xyz")
+
+                setEnableBrotli(true)
+                setEnableHttpCache(HttpEngine.Builder.HTTP_CACHE_IN_MEMORY, 10_000_000)
+                setConnectionMigrationOptions(
+                    ConnectionMigrationOptions.Builder()
+                        .setDefaultNetworkMigration(ConnectionMigrationOptions.MIGRATION_OPTION_ENABLED)
+                        .setPathDegradationMigration(ConnectionMigrationOptions.MIGRATION_OPTION_ENABLED)
+                        .setAllowNonDefaultNetworkUsage(ConnectionMigrationOptions.MIGRATION_OPTION_ENABLED)
+                        .build(),
+                )
+                addQuicHint("github.com", 443, 443)
+            }
+        })
+
+        val response = client.get("https://github.com/robots.txt")
+
+        assertContains(response.bodyAsText(), "Disallow")
+    }
+
+    @Test
+    fun testUrlConnection() = runTest {
+        val client = HttpClient(Android.create {
+            httpEngineDisabled = true
+        })
+
+        val response = client.get("https://github.com/robots.txt")
+
+        println(response.bodyAsText())
+        assertContains(response.bodyAsText(), "Disallow")
+    }
+}

ktor-client/ktor-client-android/jvm/src/io/ktor/client/engine/android/Android14URLConnectionFactory.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2014-2024 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package io.ktor.client.engine.android
+
+import android.net.http.*
+import java.net.*
+
+internal class Android14HttpEngineFactory(private val config: AndroidEngineConfig) : URLConnectionFactory {
+    private val engine = buildEngine()
+
+    fun buildEngine(): HttpEngine {
+        return HttpEngine.Builder(config.context!!)
+            .apply(config.httpEngineConfig)
+            .build()
+    }
+
+    override operator fun invoke(urlString: String): HttpURLConnection {
+        return engine.openConnection(URL(urlString)) as HttpURLConnection
+    }
+}

ktor-client/ktor-client-android/jvm/src/io/ktor/client/engine/android/AndroidClientEngine.kt

@@ -31,6 +31,12 @@ public class AndroidClientEngine(override val config: AndroidEngineConfig) : Htt
 
     override val supportedCapabilities: Set<HttpClientEngineCapability<*>> = setOf(HttpTimeoutCapability, SSECapability)
 
+    private val urlFactory = if (config.httpEngineDisabled || !isAndroid14() || config.proxy != null || config.context == null) {
+        URLConnectionFactory.StandardURLConnectionFactory(config)
+    } else {
+        Android14HttpEngineFactory(config)
+    }
+
     override suspend fun execute(data: HttpRequestData): HttpResponseData {
         val callContext = callContext()
 
@@ -41,12 +47,13 @@ public class AndroidClientEngine(override val config: AndroidEngineConfig) : Htt
         val contentLength: Long? = data.headers[HttpHeaders.ContentLength]?.toLong()
             ?: outgoingContent.contentLength
 
-        val connection: HttpURLConnection = getProxyAwareConnection(url).apply {
+        val connection: HttpURLConnection = urlFactory(url).apply {
             connectTimeout = config.connectTimeout
             readTimeout = config.socketTimeout
 
             setupTimeoutAttributes(data)
 
+            // TODO document not active on Android 14
             if (this is HttpsURLConnection) {
                 config.sslManager(this)
             }
@@ -90,7 +97,7 @@ public class AndroidClientEngine(override val config: AndroidEngineConfig) : Htt
                 .mapKeys { it.key?.lowercase(Locale.getDefault()) ?: "" }
                 .filter { it.key.isNotBlank() }
 
-            val version: HttpProtocolVersion = HttpProtocolVersion.HTTP_1_1
+            val version: HttpProtocolVersion = urlFactory.protocolFromRequest(connection)
             val responseHeaders = HeadersImpl(headerFields)
 
             val responseBody: Any = data.attributes.getOrNull(ResponseAdapterAttributeKey)
@@ -100,12 +107,6 @@ public class AndroidClientEngine(override val config: AndroidEngineConfig) : Htt
             HttpResponseData(statusCode, requestTime, responseHeaders, version, responseBody, callContext)
         }
     }
-
-    private fun getProxyAwareConnection(urlString: String): HttpURLConnection {
-        val url = URL(urlString)
-        val connection: URLConnection = config.proxy?.let { url.openConnection(it) } ?: url.openConnection()
-        return connection as HttpURLConnection
-    }
 }
 
 @OptIn(DelicateCoroutinesApi::class)

ktor-client/ktor-client-android/jvm/src/io/ktor/client/engine/android/AndroidEngineConfig.kt

@@ -4,6 +4,7 @@
 
 package io.ktor.client.engine.android
 
+import android.net.http.*
 import io.ktor.client.engine.*
 import java.net.*
 import javax.net.ssl.*
@@ -35,4 +36,19 @@ public class AndroidEngineConfig : HttpClientEngineConfig() {
      * Allows you to set engine-specific request configuration.
      */
     public var requestConfig: HttpURLConnection.() -> Unit = {}
+
+    /**
+     * Allows you to set engine-specific request configuration.
+     */
+    public var httpEngineConfig: HttpEngine.Builder.() -> Unit = {}
+
+    internal var httpEngineDisabled = false
+
+    /**
+     * Allows you to set engine-specific request configuration.
+     */
+    public var context: android.content.Context? = null
+        set(value) {
+            field = value
+        }
 }

ktor-client/ktor-client-android/jvm/src/io/ktor/client/engine/android/AndroidURLConnectionUtils.kt

@@ -4,6 +4,7 @@
 
 package io.ktor.client.engine.android
 
+import android.os.*
 import io.ktor.client.network.sockets.*
 import io.ktor.client.plugins.*
 import io.ktor.client.request.*
@@ -83,3 +84,7 @@ internal fun HttpURLConnection.content(callContext: CoroutineContext, request: H
  */
 private fun Throwable.isTimeoutException(): Boolean =
     this is java.net.SocketTimeoutException || (this is ConnectException && message?.contains("timed out") ?: false)
+
+internal val isAndroid: Boolean = "Dalvik" == System.getProperty("java.vm.name")
+
+internal fun isAndroid14() = isAndroid && Build.VERSION.SDK_INT >= 34

ktor-client/ktor-client-android/jvm/src/io/ktor/client/engine/android/URLConnectionFactory.kt

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2014-2024 JetBrains s.r.o and contributors. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package io.ktor.client.engine.android
+
+import io.ktor.http.*
+import java.net.*
+
+internal interface URLConnectionFactory {
+    operator fun invoke(urlString: String): HttpURLConnection
+    fun protocolFromRequest(connection: HttpURLConnection): HttpProtocolVersion {
+        return HttpProtocolVersion.HTTP_1_1
+    }
+
+    class StandardURLConnectionFactory(val config: AndroidEngineConfig) : URLConnectionFactory {
+        override operator fun invoke(urlString: String): HttpURLConnection {
+            val url = URL(urlString)
+            val connection: URLConnection = config.proxy?.let { url.openConnection(it) } ?: url.openConnection()
+            return connection as HttpURLConnection
+        }
+
+        // Work out how to get version
+//        override fun protocolFromRequest(connection: HttpURLConnection): HttpProtocolVersion {
+//            return connection
+//        }
+    }
+}

ktor-client/ktor-client-android/jvm/test/io/ktor/client/engine/android/AndroidSpecificHttpsTest.kt

@@ -4,6 +4,7 @@
 
 package io.ktor.client.engine.android
 
+import android.net.http.*
 import io.ktor.client.*
 import io.ktor.client.call.*
 import io.ktor.client.engine.*
@@ -101,4 +102,44 @@ class AndroidSpecificHttpsTest : TestWithKtor() {
             assertEquals("Hello, world", actual)
         }
     }
+
+    @Test
+    fun withAndroid14Customisations(): Unit = runBlocking {
+        HttpClient(
+            Android.config {
+//                this.context = context
+                httpEngineConfig = {
+//                    val cacheDir =
+//                        context.cacheDir.resolve("httpEngine").also {
+//                            it.mkdirs()
+//                        }
+
+                    setEnableBrotli(true)
+//                    setStoragePath(cacheDir.path)
+                    setConnectionMigrationOptions(
+                        ConnectionMigrationOptions.Builder()
+                            .setDefaultNetworkMigration(ConnectionMigrationOptions.MIGRATION_OPTION_ENABLED)
+                            .setPathDegradationMigration(ConnectionMigrationOptions.MIGRATION_OPTION_ENABLED)
+                            .setAllowNonDefaultNetworkUsage(ConnectionMigrationOptions.MIGRATION_OPTION_ENABLED)
+                            .build(),
+                    )
+                    setDnsOptions(
+                        DnsOptions.Builder()
+                            .setUseHttpStackDnsResolver(DnsOptions.DNS_OPTION_ENABLED)
+                            .setStaleDns(DnsOptions.DNS_OPTION_ENABLED)
+                            .setPersistHostCache(DnsOptions.DNS_OPTION_ENABLED)
+                            .build(),
+                    )
+                    setQuicOptions(
+                        QuicOptions.Builder()
+                            .build(),
+                    )
+                    addQuicHint("www.google.com", 443, 443)
+                }
+            }
+        ).use { client ->
+            val actual = client.get("https://127.0.0.1:$serverPort/").body<String>()
+            assertEquals("Hello, world", actual)
+        }
+    }
 }