android: Update examples to display errors with a red background

examples/java/hello_world/BUILD

@@ -4,15 +4,16 @@ android_binary(
     name = "hello_envoy",
     srcs = [
         "MainActivity.java",
-        "Response.java",
-        "ResponseRecyclerViewAdapter.java",
-        "ResponseViewHolder.java",
     ],
     custom_package = "io.envoyproxy.envoymobile.helloenvoy",
     manifest = "AndroidManifest.xml",
-    resource_files = glob(["res/**"]),
+    resource_files = [
+        "res/layout/activity_main.xml",
+        "res/raw/config.yaml",
+    ],
     deps = [
         "//dist:envoy_mobile_android",
+        "//examples/kotlin/shared:hello_envoy_shared_lib",
         "@androidsdk//com.android.support:appcompat-v7-25.0.0",
         "@androidsdk//com.android.support:recyclerview-v7-25.0.0",
     ],

examples/java/hello_world/MainActivity.java

@@ -9,6 +9,11 @@
 import android.support.v7.widget.LinearLayoutManager;
 import android.support.v7.widget.RecyclerView;
 import android.util.Log;
+import io.envoyproxy.envoymobile.Envoy;
+import io.envoyproxy.envoymobile.shared.Failure;
+import io.envoyproxy.envoymobile.shared.Response;
+import io.envoyproxy.envoymobile.shared.ResponseRecyclerViewAdapter;
+import io.envoyproxy.envoymobile.shared.Success;
 
 import java.io.BufferedReader;
 import java.io.IOException;
@@ -19,8 +24,6 @@
 import java.util.List;
 import java.util.concurrent.TimeUnit;
 
-import io.envoyproxy.envoymobile.Envoy;
-
 public class MainActivity extends Activity {
   private static final String ENDPOINT =
       "http://0.0.0.0:9001/api.lyft.com/static/demo/hello_world.txt";
@@ -33,8 +36,6 @@ public class MainActivity extends Activity {
 
   private HandlerThread thread = new HandlerThread(REQUEST_HANDLER_THREAD_NAME);
 
-  private Envoy envoy;
-
   @Override
   protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
@@ -44,14 +45,14 @@ protected void onCreate(Bundle savedInstanceState) {
     Envoy.load(context);
 
     // Create envoy instance with config.
-    String config = null;
+    String config;
     try {
       config = loadEnvoyConfig(getBaseContext(), R.raw.config);
     } catch (RuntimeException e) {
       Log.d("MainActivity", "exception getting config.", e);
       throw new RuntimeException("Can't get config to run envoy.");
     }
-    envoy = new Envoy(context, config);
+    Envoy envoy = new Envoy(context, config);
 
     recyclerView = (RecyclerView)findViewById(R.id.recycler_view);
     recyclerView.setLayoutManager(new LinearLayoutManager(this));
@@ -68,12 +69,8 @@ protected void onCreate(Bundle savedInstanceState) {
     handler.postDelayed(new Runnable() {
       @Override
       public void run() {
-        try {
-          final Response response = makeRequest();
-          recyclerView.post((Runnable)() -> adapter.add(response));
-        } catch (IOException e) {
-          Log.d("MainActivity", "exception making request.", e);
-        }
+        final Response response = makeRequest();
+        recyclerView.post((Runnable)() -> adapter.add(response));
 
         // Make a call again
         handler.postDelayed(this, TimeUnit.SECONDS.toMillis(1));
@@ -86,21 +83,25 @@ protected void onDestroy() {
     thread.quit();
   }
 
-  private Response makeRequest() throws IOException {
-    URL url = new URL(ENDPOINT);
-    // Open connection to the envoy thread listening locally on port 9001.
-    HttpURLConnection connection = (HttpURLConnection)url.openConnection();
-    int status = connection.getResponseCode();
-    if (status != 200) {
-      throw new IOException("non 200 status: " + status);
+  private Response makeRequest() {
+    try {
+      URL url = new URL(ENDPOINT);
+      // Open connection to the envoy thread listening locally on port 9001.
+      HttpURLConnection connection = (HttpURLConnection)url.openConnection();
+      int status = connection.getResponseCode();
+      if (status == 200) {
+        List<String> serverHeaderField = connection.getHeaderFields().get(ENVOY_SERVER_HEADER);
+        InputStream inputStream = connection.getInputStream();
+        String body = deserialize(inputStream);
+        inputStream.close();
+        return new Success(body,
+                           serverHeaderField != null ? String.join(", ", serverHeaderField) : "");
+      } else {
+        return new Failure("failed with status " + status);
+      }
+    } catch (Exception e) {
+      return new Failure(e.getMessage());
     }
-
-    List<String> serverHeaderField = connection.getHeaderFields().get(ENVOY_SERVER_HEADER);
-    InputStream inputStream = connection.getInputStream();
-    String body = deserialize(inputStream);
-    inputStream.close();
-    return new Response(body,
-                        serverHeaderField != null ? String.join(", ", serverHeaderField) : "");
   }
 
   private String deserialize(InputStream inputStream) throws IOException {

examples/kotlin/hello_world/BUILD

@@ -18,18 +18,16 @@ kt_android_library(
     name = "hello_envoy_kt_lib",
     srcs = [
         "MainActivity.kt",
-        "Response.kt",
-        "ResponseRecyclerViewAdapter.kt",
-        "ResponseViewHolder.kt",
     ],
     custom_package = "io.envoyproxy.envoymobile.helloenvoykotlin",
     manifest = "AndroidManifest.xml",
-    resource_files = glob([
-        "res/**/*.xml",
-        "res/**/*.yaml",
-    ]),
+    resource_files = [
+        "res/layout/activity_main.xml",
+        "res/raw/config.yaml",
+    ],
     deps = [
         "//dist:envoy_mobile_android",
+        "//examples/kotlin/shared:hello_envoy_shared_lib",
         "@androidsdk//com.android.support:appcompat-v7-25.0.0",
         "@androidsdk//com.android.support:recyclerview-v7-25.0.0",
     ],

examples/kotlin/hello_world/MainActivity.kt

@@ -9,15 +9,17 @@ import android.support.v7.widget.DividerItemDecoration
 import android.support.v7.widget.LinearLayoutManager
 import android.support.v7.widget.RecyclerView
 import android.util.Log
-
+import io.envoyproxy.envoymobile.Envoy
+import io.envoyproxy.envoymobile.shared.Failure
+import io.envoyproxy.envoymobile.shared.Response
+import io.envoyproxy.envoymobile.shared.ResponseRecyclerViewAdapter
+import io.envoyproxy.envoymobile.shared.Success
 import java.io.IOException
 import java.io.InputStream
 import java.net.HttpURLConnection
 import java.net.URL
 import java.util.concurrent.TimeUnit
 
-import io.envoyproxy.envoymobile.Envoy
-
 private const val REQUEST_HANDLER_THREAD_NAME = "hello_envoy_kt"
 private const val ENDPOINT = "http://0.0.0.0:9001/api.lyft.com/static/demo/hello_world.txt"
 private const val ENVOY_SERVER_HEADER = "server"
@@ -32,7 +34,7 @@ class MainActivity : Activity() {
     setContentView(R.layout.activity_main)
 
     Envoy.load(baseContext)
- 
+
     // Create Envoy instance with config.
     envoy = Envoy(baseContext, loadEnvoyConfig(baseContext, R.raw.config))
 
@@ -51,7 +53,7 @@ class MainActivity : Activity() {
       override fun run() {
         try {
           val response = makeRequest()
-          recyclerView.post({ adapter.add(response) })
+          recyclerView.post { adapter.add(response) }
         } catch (e: IOException) {
           Log.d("MainActivity", "exception making request.", e)
         }
@@ -68,19 +70,23 @@ class MainActivity : Activity() {
   }
 
   private fun makeRequest(): Response {
-    val url = URL(ENDPOINT)
-    // Open connection to the envoy thread listening locally on port 9001
-    val connection = url.openConnection() as HttpURLConnection
-    val status = connection.responseCode
-    if (status != 200) {
-      throw IOException("non 200 status: $status")
+    return  try {
+      val url = URL(ENDPOINT)
+      // Open connection to the envoy thread listening locally on port 9001
+      val connection = url.openConnection() as HttpURLConnection
+      val status = connection.responseCode
+      if (status == 200) {
+        val serverHeaderField = connection.headerFields[ENVOY_SERVER_HEADER]
+        val inputStream = connection.inputStream
+        val body = deserialize(inputStream)
+        inputStream.close()
+        Success(body, serverHeaderField?.joinToString(separator = ", ") ?: "")
+      } else {
+        Failure("failed with status: $status")
+      }
+    } catch (e: IOException) {
+      Failure(e.message ?: "failed with exception")
     }
-
-    val serverHeaderField = connection.headerFields[ENVOY_SERVER_HEADER]
-    val inputStream = connection.inputStream
-    val body = deserialize(inputStream)
-    inputStream.close()
-    return Response(body, serverHeaderField?.joinToString(separator = ", ") ?: "")
   }
 
   private fun deserialize(inputStream: InputStream): String {

examples/kotlin/shared/AndroidManifest.xml

@@ -0,0 +1,5 @@
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+          package="io.envoyproxy.envoymobile.shared"
+          android:versionCode="1"
+          android:versionName="0.1">
+</manifest>

examples/kotlin/shared/BUILD

@@ -0,0 +1,25 @@
+licenses(["notice"])  # Apache 2
+
+load("@envoy//bazel:envoy_build_system.bzl", "envoy_package")
+load("@io_bazel_rules_kotlin//kotlin:kotlin.bzl", "kt_android_library")
+
+envoy_package()
+
+kt_android_library(
+    name = "hello_envoy_shared_lib",
+    srcs = [
+        "Response.kt",
+        "ResponseRecyclerViewAdapter.kt",
+        "ResponseViewHolder.kt",
+    ],
+    custom_package = "io.envoyproxy.envoymobile.shared",
+    manifest = "AndroidManifest.xml",
+    resource_files = glob([
+        "res/layout/item.xml",
+        "res/values/colors.xml",
+        "res/values/strings.xml",
+    ]),
+    deps = [
+        "@androidsdk//com.android.support:recyclerview-v7-25.0.0",
+    ],
+)

examples/kotlin/shared/Response.kt

@@ -0,0 +1,16 @@
+package io.envoyproxy.envoymobile.shared
+
+// Response is a class to handle HTTP responses.
+sealed class Response {
+  fun fold(success: (Success) -> Unit, failure: (Failure) -> Unit) = when (this) {
+    is Success -> success(this)
+    is Failure -> failure(this)
+  }
+}
+
+data class Success(val title: String, val header: String) : Response()
+
+data class Failure(val message: String) : Response()
+
+
+