examples: update Android examples

Updates include:

* Build file and dependency updates
* Correcting the gradle wrapper for the clientcache example
* Lint fixes (including making AsyncTask subclasses static)
* Dropping the m-prefix from member variables
* Fixing the code indentation
* Fixing and enabling proguard for the routeguide example.

16 files changed, 536 insertions, 479 deletions

diff --git a/examples/android/clientcache/app/build.gradle b/examples/android/clientcache/app/build.gradle
index 5c0c647dc..6d4f3659d 100644
--- a/examples/android/clientcache/app/build.gradle
+++ b/examples/android/clientcache/app/build.gradle
@@ -2,26 +2,28 @@ apply plugin: 'com.android.application'
 apply plugin: 'com.google.protobuf'
 
 android {
-    compileSdkVersion 25
-    buildToolsVersion "25.0.2"
+    compileSdkVersion 27
 
     defaultConfig {
         applicationId "io.grpc.android.clientcacheexample"
         minSdkVersion 19
-        targetSdkVersion 25
+        targetSdkVersion 27
         multiDexEnabled true
         versionCode 1
         versionName "1.0"
         testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
     }
     buildTypes {
+        debug {
+            minifyEnabled false
+        }
         release {
             minifyEnabled true
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
     lintOptions {
-        disable 'InvalidPackage', 'HardcodedText'
+        disable 'GoogleAppIndexingWarning', 'HardcodedText', 'InvalidPackage'
         textReport true
         textOutput "stdout"
     }
@@ -53,7 +55,7 @@ protobuf {
 }
 
 dependencies {
-    compile 'com.android.support:appcompat-v7:25.0.0'
+    compile 'com.android.support:appcompat-v7:27.0.2'
 
     // You need to build grpc-java to obtain these libraries below.
     compile 'io.grpc:grpc-okhttp:1.9.0-SNAPSHOT' // CURRENT_GRPC_VERSION
@@ -62,6 +64,6 @@ dependencies {
     compile 'javax.annotation:javax.annotation-api:1.2'
 
     testCompile 'junit:junit:4.12'
-    testCompile 'com.google.truth:truth:0.28'
+    testCompile 'com.google.truth:truth:0.36'
     testCompile 'io.grpc:grpc-testing:1.9.0-SNAPSHOT'
 }
diff --git a/examples/android/clientcache/app/src/main/AndroidManifest.xml b/examples/android/clientcache/app/src/main/AndroidManifest.xml
index d31cbd940..6fc8e940d 100644
--- a/examples/android/clientcache/app/src/main/AndroidManifest.xml
+++ b/examples/android/clientcache/app/src/main/AndroidManifest.xml
@@ -5,7 +5,7 @@
     <uses-permission android:name="android.permission.INTERNET" />
 
     <application
-        android:allowBackup="true"
+        android:allowBackup="false"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/Base.V7.Theme.AppCompat.Light" >
diff --git a/examples/android/clientcache/app/src/main/java/io/grpc/clientcacheexample/ClientCacheExampleActivity.java b/examples/android/clientcache/app/src/main/java/io/grpc/clientcacheexample/ClientCacheExampleActivity.java
index 831c1030a..036e3019f 100644
--- a/examples/android/clientcache/app/src/main/java/io/grpc/clientcacheexample/ClientCacheExampleActivity.java
+++ b/examples/android/clientcache/app/src/main/java/io/grpc/clientcacheexample/ClientCacheExampleActivity.java
@@ -16,6 +16,7 @@
 
 package io.grpc.clientcacheexample;
 
+import android.app.Activity;
 import android.content.Context;
 import android.os.AsyncTask;
 import android.os.Bundle;
@@ -41,16 +42,17 @@ import io.grpc.examples.helloworld.HelloRequest;
 import io.grpc.stub.ClientCalls;
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.lang.ref.WeakReference;
 import java.util.concurrent.TimeUnit;
 
 public final class ClientCacheExampleActivity extends AppCompatActivity {
   private static final int CACHE_SIZE_IN_BYTES = 1 * 1024 * 1024; // 1MB
   private static final String TAG = "grpcCacheExample";
-  private Button mSendButton;
-  private EditText mHostEdit;
-  private EditText mPortEdit;
-  private EditText mMessageEdit;
-  private TextView mResultText;
+  private Button sendButton;
+  private EditText hostEdit;
+  private EditText portEdit;
+  private EditText messageEdit;
+  private TextView resultText;
   private CheckBox getCheckBox;
   private CheckBox noCacheCheckBox;
   private CheckBox onlyIfCachedCheckBox;
@@ -60,70 +62,79 @@ public final class ClientCacheExampleActivity extends AppCompatActivity {
   protected void onCreate(Bundle savedInstanceState) {
     super.onCreate(savedInstanceState);
     setContentView(R.layout.activity_clientcacheexample);
-    mSendButton = (Button) findViewById(R.id.send_button);
-    mHostEdit = (EditText) findViewById(R.id.host_edit_text);
-    mPortEdit = (EditText) findViewById(R.id.port_edit_text);
-    mMessageEdit = (EditText) findViewById(R.id.message_edit_text);
+    sendButton = (Button) findViewById(R.id.send_button);
+    hostEdit = (EditText) findViewById(R.id.host_edit_text);
+    portEdit = (EditText) findViewById(R.id.port_edit_text);
+    messageEdit = (EditText) findViewById(R.id.message_edit_text);
     getCheckBox = (CheckBox) findViewById(R.id.get_checkbox);
     noCacheCheckBox = (CheckBox) findViewById(R.id.no_cache_checkbox);
     onlyIfCachedCheckBox = (CheckBox) findViewById(R.id.only_if_cached_checkbox);
-    mResultText = (TextView) findViewById(R.id.grpc_response_text);
-    mResultText.setMovementMethod(new ScrollingMovementMethod());
-
+    resultText = (TextView) findViewById(R.id.grpc_response_text);
+    resultText.setMovementMethod(new ScrollingMovementMethod());
     cache = SafeMethodCachingInterceptor.newLruCache(CACHE_SIZE_IN_BYTES);
   }
 
   /** Sends RPC. Invoked when app button is pressed. */
   public void sendMessage(View view) {
     ((InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE))
-        .hideSoftInputFromWindow(mHostEdit.getWindowToken(), 0);
-    mSendButton.setEnabled(false);
-    new GrpcTask().execute();
+        .hideSoftInputFromWindow(hostEdit.getWindowToken(), 0);
+    sendButton.setEnabled(false);
+    resultText.setText("");
+    new GrpcTask(this, cache)
+        .execute(
+            hostEdit.getText().toString(),
+            messageEdit.getText().toString(),
+            portEdit.getText().toString(),
+            getCheckBox.isChecked(),
+            noCacheCheckBox.isChecked(),
+            onlyIfCachedCheckBox.isChecked());
   }
 
-  private class GrpcTask extends AsyncTask<Void, Void, String> {
-    private String host;
-    private String message;
-    private int port;
+  private static class GrpcTask extends AsyncTask<Object, Void, String> {
+    private final WeakReference<Activity> activityReference;
+    private final SafeMethodCachingInterceptor.Cache cache;
     private ManagedChannel channel;
 
-    @Override
-    protected void onPreExecute() {
-      host = mHostEdit.getText().toString();
-      message = mMessageEdit.getText().toString();
-      String portStr = mPortEdit.getText().toString();
-      port = TextUtils.isEmpty(portStr) ? 0 : Integer.valueOf(portStr);
-      mResultText.setText("");
+    private GrpcTask(Activity activity, SafeMethodCachingInterceptor.Cache cache) {
+      this.activityReference = new WeakReference<Activity>(activity);
+      this.cache = cache;
     }
 
     @Override
-    protected String doInBackground(Void... nothing) {
+    protected String doInBackground(Object... params) {
+      String host = (String) params[0];
+      String message = (String) params[1];
+      String portStr = (String) params[2];
+      boolean useGet = (boolean) params[3];
+      boolean noCache = (boolean) params[4];
+      boolean onlyIfCached = (boolean) params[5];
+      int port = TextUtils.isEmpty(portStr) ? 0 : Integer.valueOf(portStr);
       try {
         channel = ManagedChannelBuilder.forAddress(host, port).usePlaintext(true).build();
         Channel channelToUse =
             ClientInterceptors.intercept(
                 channel, SafeMethodCachingInterceptor.newSafeMethodCachingInterceptor(cache));
-        HelloRequest message = HelloRequest.newBuilder().setName(this.message).build();
+        HelloRequest request = HelloRequest.newBuilder().setName(message).build();
         HelloReply reply;
-        if (getCheckBox.isChecked()) {
+        if (useGet) {
           MethodDescriptor<HelloRequest, HelloReply> safeCacheableUnaryCallMethod =
               GreeterGrpc.getSayHelloMethod().toBuilder().setSafe(true).build();
           CallOptions callOptions = CallOptions.DEFAULT;
-          if (noCacheCheckBox.isChecked()) {
+          if (noCache) {
             callOptions =
                 callOptions.withOption(SafeMethodCachingInterceptor.NO_CACHE_CALL_OPTION, true);
           }
-          if (onlyIfCachedCheckBox.isChecked()) {
+          if (onlyIfCached) {
             callOptions =
                 callOptions.withOption(
                     SafeMethodCachingInterceptor.ONLY_IF_CACHED_CALL_OPTION, true);
           }
           reply =
               ClientCalls.blockingUnaryCall(
-                  channelToUse, safeCacheableUnaryCallMethod, callOptions, message);
+                  channelToUse, safeCacheableUnaryCallMethod, callOptions, request);
         } else {
           GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(channelToUse);
-          reply = stub.sayHello(message);
+          reply = stub.sayHello(request);
         }
         return reply.getMessage();
       } catch (Exception e) {
@@ -145,8 +156,14 @@ public final class ClientCacheExampleActivity extends AppCompatActivity {
           Thread.currentThread().interrupt();
         }
       }
-      mResultText.setText(result);
-      mSendButton.setEnabled(true);
+      Activity activity = activityReference.get();
+      if (activity == null) {
+        return;
+      }
+      TextView resultText = (TextView) activity.findViewById(R.id.grpc_response_text);
+      Button sendButton = (Button) activity.findViewById(R.id.send_button);
+      resultText.setText(result);
+      sendButton.setEnabled(true);
     }
   }
 }
diff --git a/examples/android/clientcache/app/src/main/java/io/grpc/clientcacheexample/SafeMethodCachingInterceptor.java b/examples/android/clientcache/app/src/main/java/io/grpc/clientcacheexample/SafeMethodCachingInterceptor.java
index 4ae0c01c5..6dfc6d48d 100644
--- a/examples/android/clientcache/app/src/main/java/io/grpc/clientcacheexample/SafeMethodCachingInterceptor.java
+++ b/examples/android/clientcache/app/src/main/java/io/grpc/clientcacheexample/SafeMethodCachingInterceptor.java
@@ -14,6 +14,7 @@ import io.grpc.ForwardingClientCallListener;
 import io.grpc.Metadata;
 import io.grpc.MethodDescriptor;
 import io.grpc.Status;
+import java.util.Locale;
 import java.util.Objects;
 import java.util.concurrent.TimeUnit;
 
@@ -199,7 +200,7 @@ final class SafeMethodCachingInterceptor implements ClientInterceptor {
                       } else if (directive.equalsIgnoreCase("no-transform")) {
                         cacheResponse = false;
                         break;
-                      } else if (directive.toLowerCase().startsWith("max-age")) {
+                      } else if (directive.toLowerCase(Locale.US).startsWith("max-age")) {
                         String[] parts = directive.split("=");
                         if (parts.length == 2) {
                           try {
diff --git a/examples/android/clientcache/build.gradle b/examples/android/clientcache/build.gradle
index 6f6011c3c..506cf47e7 100644
--- a/examples/android/clientcache/build.gradle
+++ b/examples/android/clientcache/build.gradle
@@ -2,10 +2,11 @@
 
 buildscript {
     repositories {
+        google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.1'
+        classpath 'com.android.tools.build:gradle:3.0.1'
         classpath "com.google.protobuf:protobuf-gradle-plugin:0.8.3"
 
         // NOTE: Do not place your application dependencies here; they belong
@@ -15,6 +16,7 @@ buildscript {
 
 allprojects {
     repositories {
+        google()
         jcenter()
         mavenLocal()
     }
diff --git a/examples/android/helloworld/app/build.gradle b/examples/android/helloworld/app/build.gradle
index 19aa25668..9a3ed0c3a 100644
--- a/examples/android/helloworld/app/build.gradle
+++ b/examples/android/helloworld/app/build.gradle
@@ -2,25 +2,27 @@ apply plugin: 'com.android.application'
 apply plugin: 'com.google.protobuf'
 
 android {
-    compileSdkVersion 22
-    buildToolsVersion "25.0.2"
+    compileSdkVersion 27
 
     defaultConfig {
         applicationId "io.grpc.android.helloworldexample"
         // API level 14+ is required for TLS since Google Play Services v10.2
         minSdkVersion 14
-        targetSdkVersion 22
+        targetSdkVersion 27
         versionCode 1
         versionName "1.0"
     }
     buildTypes {
+        debug {
+            minifyEnabled false
+        }
         release {
             minifyEnabled true
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
     lintOptions {
-        disable 'InvalidPackage', 'HardcodedText'
+        disable 'GoogleAppIndexingWarning', 'HardcodedText', 'InvalidPackage'
         textReport true
         textOutput "stdout"
     }
@@ -52,7 +54,7 @@ protobuf {
 }
 
 dependencies {
-    compile 'com.android.support:appcompat-v7:22.1.1'
+    compile 'com.android.support:appcompat-v7:27.0.2'
 
     // You need to build grpc-java to obtain these libraries below.
     compile 'io.grpc:grpc-okhttp:1.10.0-SNAPSHOT' // CURRENT_GRPC_VERSION
diff --git a/examples/android/helloworld/app/src/main/AndroidManifest.xml b/examples/android/helloworld/app/src/main/AndroidManifest.xml
index 8c40f1168..eee4057cd 100644
--- a/examples/android/helloworld/app/src/main/AndroidManifest.xml
+++ b/examples/android/helloworld/app/src/main/AndroidManifest.xml
@@ -5,7 +5,7 @@
     <uses-permission android:name="android.permission.INTERNET" />
 
     <application
-        android:allowBackup="true"
+        android:allowBackup="false"
         android:icon="@mipmap/ic_launcher"
         android:label="@string/app_name"
         android:theme="@style/Base.V7.Theme.AppCompat.Light" >
diff --git a/examples/android/helloworld/app/src/main/java/io/grpc/helloworldexample/HelloworldActivity.java b/examples/android/helloworld/app/src/main/java/io/grpc/helloworldexample/HelloworldActivity.java
index 6a1628b69..ef730931c 100644
--- a/examples/android/helloworld/app/src/main/java/io/grpc/helloworldexample/HelloworldActivity.java
+++ b/examples/android/helloworld/app/src/main/java/io/grpc/helloworldexample/HelloworldActivity.java
@@ -16,6 +16,7 @@
 
 package io.grpc.helloworldexample;
 
+import android.app.Activity;
 import android.content.Context;
 import android.os.AsyncTask;
 import android.os.Bundle;
@@ -27,86 +28,91 @@ import android.view.inputmethod.InputMethodManager;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.TextView;
-
 import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;
 import io.grpc.examples.helloworld.GreeterGrpc;
 import io.grpc.examples.helloworld.HelloReply;
 import io.grpc.examples.helloworld.HelloRequest;
-
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.lang.ref.WeakReference;
 import java.util.concurrent.TimeUnit;
 
 public class HelloworldActivity extends AppCompatActivity {
-    private Button mSendButton;
-    private EditText mHostEdit;
-    private EditText mPortEdit;
-    private EditText mMessageEdit;
-    private TextView mResultText;
+  private Button sendButton;
+  private EditText hostEdit;
+  private EditText portEdit;
+  private EditText messageEdit;
+  private TextView resultText;
 
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_helloworld);
-        mSendButton = (Button) findViewById(R.id.send_button);
-        mHostEdit = (EditText) findViewById(R.id.host_edit_text);
-        mPortEdit = (EditText) findViewById(R.id.port_edit_text);
-        mMessageEdit = (EditText) findViewById(R.id.message_edit_text);
-        mResultText = (TextView) findViewById(R.id.grpc_response_text);
-        mResultText.setMovementMethod(new ScrollingMovementMethod());
-    }
+  @Override
+  protected void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    setContentView(R.layout.activity_helloworld);
+    sendButton = (Button) findViewById(R.id.send_button);
+    hostEdit = (EditText) findViewById(R.id.host_edit_text);
+    portEdit = (EditText) findViewById(R.id.port_edit_text);
+    messageEdit = (EditText) findViewById(R.id.message_edit_text);
+    resultText = (TextView) findViewById(R.id.grpc_response_text);
+    resultText.setMovementMethod(new ScrollingMovementMethod());
+  }
 
-    public void sendMessage(View view) {
-        ((InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE))
-                .hideSoftInputFromWindow(mHostEdit.getWindowToken(), 0);
-        mSendButton.setEnabled(false);
-        new GrpcTask().execute();
-    }
+  public void sendMessage(View view) {
+    ((InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE))
+        .hideSoftInputFromWindow(hostEdit.getWindowToken(), 0);
+    sendButton.setEnabled(false);
+    resultText.setText("");
+    new GrpcTask(this)
+        .execute(
+            hostEdit.getText().toString(),
+            messageEdit.getText().toString(),
+            portEdit.getText().toString());
+  }
 
-    private class GrpcTask extends AsyncTask<Void, Void, String> {
-        private String mHost;
-        private String mMessage;
-        private int mPort;
-        private ManagedChannel mChannel;
+  private static class GrpcTask extends AsyncTask<String, Void, String> {
+    private final WeakReference<Activity> activityReference;
+    private ManagedChannel channel;
 
-        @Override
-        protected void onPreExecute() {
-            mHost = mHostEdit.getText().toString();
-            mMessage = mMessageEdit.getText().toString();
-            String portStr = mPortEdit.getText().toString();
-            mPort = TextUtils.isEmpty(portStr) ? 0 : Integer.valueOf(portStr);
-            mResultText.setText("");
-        }
+    private GrpcTask(Activity activity) {
+      this.activityReference = new WeakReference<Activity>(activity);
+    }
 
-        @Override
-        protected String doInBackground(Void... nothing) {
-            try {
-                mChannel = ManagedChannelBuilder.forAddress(mHost, mPort)
-                    .usePlaintext(true)
-                    .build();
-                GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(mChannel);
-                HelloRequest message = HelloRequest.newBuilder().setName(mMessage).build();
-                HelloReply reply = stub.sayHello(message);
-                return reply.getMessage();
-            } catch (Exception e) {
-                StringWriter sw = new StringWriter();
-                PrintWriter pw = new PrintWriter(sw);
-                e.printStackTrace(pw);
-                pw.flush();
-                return String.format("Failed... : %n%s", sw);
-            }
-        }
+    @Override
+    protected String doInBackground(String... params) {
+      String host = params[0];
+      String message = params[1];
+      String portStr = params[2];
+      int port = TextUtils.isEmpty(portStr) ? 0 : Integer.valueOf(portStr);
+      try {
+        channel = ManagedChannelBuilder.forAddress(host, port).usePlaintext(true).build();
+        GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(channel);
+        HelloRequest request = HelloRequest.newBuilder().setName(message).build();
+        HelloReply reply = stub.sayHello(request);
+        return reply.getMessage();
+      } catch (Exception e) {
+        StringWriter sw = new StringWriter();
+        PrintWriter pw = new PrintWriter(sw);
+        e.printStackTrace(pw);
+        pw.flush();
+        return String.format("Failed... : %n%s", sw);
+      }
+    }
 
-        @Override
-        protected void onPostExecute(String result) {
-            try {
-                mChannel.shutdown().awaitTermination(1, TimeUnit.SECONDS);
-            } catch (InterruptedException e) {
-                Thread.currentThread().interrupt();
-            }
-            mResultText.setText(result);
-            mSendButton.setEnabled(true);
-        }
+    @Override
+    protected void onPostExecute(String result) {
+      try {
+        channel.shutdown().awaitTermination(1, TimeUnit.SECONDS);
+      } catch (InterruptedException e) {
+        Thread.currentThread().interrupt();
+      }
+      Activity activity = activityReference.get();
+      if (activity == null) {
+        return;
+      }
+      TextView resultText = (TextView) activity.findViewById(R.id.grpc_response_text);
+      Button sendButton = (Button) activity.findViewById(R.id.send_button);
+      resultText.setText(result);
+      sendButton.setEnabled(true);
     }
+  }
 }
diff --git a/examples/android/helloworld/build.gradle b/examples/android/helloworld/build.gradle
index 6f6011c3c..506cf47e7 100644
--- a/examples/android/helloworld/build.gradle
+++ b/examples/android/helloworld/build.gradle
@@ -2,10 +2,11 @@
 
 buildscript {
     repositories {
+        google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.1'
+        classpath 'com.android.tools.build:gradle:3.0.1'
         classpath "com.google.protobuf:protobuf-gradle-plugin:0.8.3"
 
         // NOTE: Do not place your application dependencies here; they belong
@@ -15,6 +16,7 @@ buildscript {
 
 allprojects {
     repositories {
+        google()
         jcenter()
         mavenLocal()
     }
diff --git a/examples/android/routeguide/app/build.gradle b/examples/android/routeguide/app/build.gradle
index ed64a83d6..239291399 100644
--- a/examples/android/routeguide/app/build.gradle
+++ b/examples/android/routeguide/app/build.gradle
@@ -2,24 +2,28 @@ apply plugin: 'com.android.application'
 apply plugin: 'com.google.protobuf'
 
 android {
-    compileSdkVersion 23
-    buildToolsVersion "25.0.2"
+    compileSdkVersion 27
 
     defaultConfig {
     applicationId "io.grpc.routeguideexample"
-        minSdkVersion 23
-        targetSdkVersion 23
+        minSdkVersion 14
+        targetSdkVersion 27
         versionCode 1
         versionName "1.0"
     }
     buildTypes {
-        release {
+        debug {
             minifyEnabled false
+        }
+        release {
+            minifyEnabled true
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
     lintOptions {
-        disable 'InvalidPackage'
+        disable 'GoogleAppIndexingWarning', 'HardcodedText', 'InvalidPackage'
+        textReport true
+        textOutput "stdout"
     }
 }
 
@@ -49,7 +53,7 @@ protobuf {
 }
 
 dependencies {
-    compile 'com.android.support:appcompat-v7:23.+'
+    compile 'com.android.support:appcompat-v7:27.0.2'
 
     // You need to build grpc-java to obtain these libraries below.
     compile 'io.grpc:grpc-okhttp:1.10.0-SNAPSHOT' // CURRENT_GRPC_VERSION
diff --git a/examples/android/routeguide/app/proguard-rules.pro b/examples/android/routeguide/app/proguard-rules.pro
index e356773f2..8f066eb50 100644
--- a/examples/android/routeguide/app/proguard-rules.pro
+++ b/examples/android/routeguide/app/proguard-rules.pro
@@ -11,6 +11,7 @@
 
 -dontwarn sun.misc.Unsafe
 -dontwarn com.google.common.**
+-dontwarn javax.naming.**
 -dontwarn okio.**
 # Ignores: can't find referenced class javax.lang.model.element.Modifier
 -dontwarn com.google.errorprone.annotations.**
diff --git a/examples/android/routeguide/app/src/main/AndroidManifest.xml b/examples/android/routeguide/app/src/main/AndroidManifest.xml
index d557afc08..f7409758a 100644
--- a/examples/android/routeguide/app/src/main/AndroidManifest.xml
+++ b/examples/android/routeguide/app/src/main/AndroidManifest.xml
@@ -3,7 +3,7 @@
 
     <uses-permission android:name="android.permission.INTERNET" />
 
-    <application android:allowBackup="true"
+    <application android:allowBackup="false"
         android:label="@string/app_name"
         android:icon="@mipmap/ic_launcher"
         android:supportsRtl="true"
diff --git a/examples/android/routeguide/app/src/main/java/io/grpc/routeguideexample/RouteGuideActivity.java b/examples/android/routeguide/app/src/main/java/io/grpc/routeguideexample/RouteGuideActivity.java
index 8edb33fd1..0d090ac9a 100644
--- a/examples/android/routeguide/app/src/main/java/io/grpc/routeguideexample/RouteGuideActivity.java
+++ b/examples/android/routeguide/app/src/main/java/io/grpc/routeguideexample/RouteGuideActivity.java
@@ -27,18 +27,15 @@ import android.view.inputmethod.InputMethodManager;
 import android.widget.Button;
 import android.widget.EditText;
 import android.widget.TextView;
-
 import io.grpc.ManagedChannel;
 import io.grpc.ManagedChannelBuilder;
-import io.grpc.Status;
 import io.grpc.StatusRuntimeException;
 import io.grpc.routeguideexample.RouteGuideGrpc.RouteGuideBlockingStub;
 import io.grpc.routeguideexample.RouteGuideGrpc.RouteGuideStub;
 import io.grpc.stub.StreamObserver;
-
-import java.io.IOException;
 import java.io.PrintWriter;
 import java.io.StringWriter;
+import java.lang.ref.WeakReference;
 import java.text.MessageFormat;
 import java.util.ArrayList;
 import java.util.Iterator;
@@ -46,372 +43,407 @@ import java.util.List;
 import java.util.Random;
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
-import java.util.logging.Level;
-import java.util.logging.Logger;
 
 public class RouteGuideActivity extends AppCompatActivity {
-    private static final Logger logger = Logger.getLogger(RouteGuideActivity.class.getName());
-    private EditText mHostEdit;
-    private EditText mPortEdit;
-    private Button mStartRouteGuideButton;
-    private Button mExitRouteGuideButton;    
-    private Button mGetFeatureButton;
-    private Button mListFeaturesButton;
-    private Button mRecordRouteButton;
-    private Button mRouteChatButton;
-    private TextView mResultText;
-
-    private ManagedChannel mChannel;
-        
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_routeguide);
-        mHostEdit = (EditText) findViewById(R.id.host_edit_text);
-        mPortEdit = (EditText) findViewById(R.id.port_edit_text);
-        mStartRouteGuideButton = (Button) findViewById(R.id.start_route_guide_button);
-        mExitRouteGuideButton = (Button) findViewById(R.id.exit_route_guide_button);
-        mGetFeatureButton = (Button) findViewById(R.id.get_feature_button);
-        mListFeaturesButton = (Button) findViewById(R.id.list_features_button);
-        mRecordRouteButton = (Button) findViewById(R.id.record_route_button);
-        mRouteChatButton = (Button) findViewById(R.id.route_chat_button);
-        mResultText = (TextView) findViewById(R.id.result_text);
-        mResultText.setMovementMethod(new ScrollingMovementMethod());
-        disableButtons();
-    }
-    
-    public void startRouteGuide(View view) {
-        String host = mHostEdit.getText().toString();
-        String portStr = mPortEdit.getText().toString();
-        int port = TextUtils.isEmpty(portStr) ? 0 : Integer.valueOf(portStr);
-        ((InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE))
-                .hideSoftInputFromWindow(mHostEdit.getWindowToken(), 0);
-        mChannel = ManagedChannelBuilder.forAddress(host, port).usePlaintext(true).build();
-        mHostEdit.setEnabled(false);
-        mPortEdit.setEnabled(false);
-        mStartRouteGuideButton.setEnabled(false);
-        enableButtons();
-    }
-    
-    public void exitRouteGuide(View view) {
-        mChannel.shutdown();
-        disableButtons();
-        mHostEdit.setEnabled(true);
-        mPortEdit.setEnabled(true);
-        mStartRouteGuideButton.setEnabled(true);
+  private EditText hostEdit;
+  private EditText portEdit;
+  private Button startRouteGuideButton;
+  private Button exitRouteGuideButton;
+  private Button getFeatureButton;
+  private Button listFeaturesButton;
+  private Button recordRouteButton;
+  private Button routeChatButton;
+  private TextView resultText;
+  private ManagedChannel channel;
+
+  @Override
+  protected void onCreate(Bundle savedInstanceState) {
+    super.onCreate(savedInstanceState);
+    setContentView(R.layout.activity_routeguide);
+    hostEdit = (EditText) findViewById(R.id.host_edit_text);
+    portEdit = (EditText) findViewById(R.id.port_edit_text);
+    startRouteGuideButton = (Button) findViewById(R.id.start_route_guide_button);
+    exitRouteGuideButton = (Button) findViewById(R.id.exit_route_guide_button);
+    getFeatureButton = (Button) findViewById(R.id.get_feature_button);
+    listFeaturesButton = (Button) findViewById(R.id.list_features_button);
+    recordRouteButton = (Button) findViewById(R.id.record_route_button);
+    routeChatButton = (Button) findViewById(R.id.route_chat_button);
+    resultText = (TextView) findViewById(R.id.result_text);
+    resultText.setMovementMethod(new ScrollingMovementMethod());
+    disableButtons();
+  }
+
+  public void startRouteGuide(View view) {
+    String host = hostEdit.getText().toString();
+    String portStr = portEdit.getText().toString();
+    int port = TextUtils.isEmpty(portStr) ? 0 : Integer.valueOf(portStr);
+    ((InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE))
+        .hideSoftInputFromWindow(hostEdit.getWindowToken(), 0);
+    channel = ManagedChannelBuilder.forAddress(host, port).usePlaintext(true).build();
+    hostEdit.setEnabled(false);
+    portEdit.setEnabled(false);
+    startRouteGuideButton.setEnabled(false);
+    enableButtons();
+  }
+
+  public void exitRouteGuide(View view) {
+    channel.shutdown();
+    disableButtons();
+    hostEdit.setEnabled(true);
+    portEdit.setEnabled(true);
+    startRouteGuideButton.setEnabled(true);
+  }
+
+  public void getFeature(View view) {
+    setResultText("");
+    disableButtons();
+    new GrpcTask(new GetFeatureRunnable(), channel, this).execute();
+  }
+
+  public void listFeatures(View view) {
+    setResultText("");
+    disableButtons();
+    new GrpcTask(new ListFeaturesRunnable(), channel, this).execute();
+  }
+
+  public void recordRoute(View view) {
+    setResultText("");
+    disableButtons();
+    new GrpcTask(new RecordRouteRunnable(), channel, this).execute();
+  }
+
+  public void routeChat(View view) {
+    setResultText("");
+    disableButtons();
+    new GrpcTask(new RouteChatRunnable(), channel, this).execute();
+  }
+
+  private void setResultText(String text) {
+    resultText.setText(text);
+  }
+
+  private void disableButtons() {
+    getFeatureButton.setEnabled(false);
+    listFeaturesButton.setEnabled(false);
+    recordRouteButton.setEnabled(false);
+    routeChatButton.setEnabled(false);
+    exitRouteGuideButton.setEnabled(false);
+  }
+
+  private void enableButtons() {
+    exitRouteGuideButton.setEnabled(true);
+    getFeatureButton.setEnabled(true);
+    listFeaturesButton.setEnabled(true);
+    recordRouteButton.setEnabled(true);
+    routeChatButton.setEnabled(true);
+  }
+
+  private static class GrpcTask extends AsyncTask<Void, Void, String> {
+    private final GrpcRunnable grpcRunnable;
+    private final ManagedChannel channel;
+    private final WeakReference<RouteGuideActivity> activityReference;
+
+    GrpcTask(GrpcRunnable grpcRunnable, ManagedChannel channel, RouteGuideActivity activity) {
+      this.grpcRunnable = grpcRunnable;
+      this.channel = channel;
+      this.activityReference = new WeakReference<RouteGuideActivity>(activity);
     }
 
-    public void getFeature(View view) {
-        new GrpcTask(new GetFeatureRunnable()).execute();
+    @Override
+    protected String doInBackground(Void... nothing) {
+      try {
+        String logs =
+            grpcRunnable.run(
+                RouteGuideGrpc.newBlockingStub(channel), RouteGuideGrpc.newStub(channel));
+        return "Success!\n" + logs;
+      } catch (Exception e) {
+        StringWriter sw = new StringWriter();
+        PrintWriter pw = new PrintWriter(sw);
+        e.printStackTrace(pw);
+        pw.flush();
+        return "Failed... :\n" + sw;
+      }
     }
 
-    public void listFeatures(View view) {
-        new GrpcTask(new ListFeaturesRunnable()).execute();
+    @Override
+    protected void onPostExecute(String result) {
+      RouteGuideActivity activity = activityReference.get();
+      if (activity == null) {
+        return;
+      }
+      activity.setResultText(result);
+      activity.enableButtons();
     }
+  }
 
-    public void recordRoute(View view) {
-        new GrpcTask(new RecordRouteRunnable()).execute();
+  private interface GrpcRunnable {
+    /** Perform a grpcRunnable and return all the logs. */
+    String run(RouteGuideBlockingStub blockingStub, RouteGuideStub asyncStub) throws Exception;
+  }
+
+  private static class GetFeatureRunnable implements GrpcRunnable {
+    @Override
+    public String run(RouteGuideBlockingStub blockingStub, RouteGuideStub asyncStub)
+        throws Exception {
+      return getFeature(409146138, -746188906, blockingStub);
     }
 
-    public void routeChat(View view) {
-        new GrpcTask(new RouteChatRunnable()).execute();
+    /** Blocking unary call example. Calls getFeature and prints the response. */
+    private String getFeature(int lat, int lon, RouteGuideBlockingStub blockingStub)
+        throws StatusRuntimeException {
+      StringBuffer logs = new StringBuffer();
+      appendLogs(logs, "*** GetFeature: lat={0} lon={1}", lat, lon);
+
+      Point request = Point.newBuilder().setLatitude(lat).setLongitude(lon).build();
+
+      Feature feature;
+      feature = blockingStub.getFeature(request);
+      if (RouteGuideUtil.exists(feature)) {
+        appendLogs(
+            logs,
+            "Found feature called \"{0}\" at {1}, {2}",
+            feature.getName(),
+            RouteGuideUtil.getLatitude(feature.getLocation()),
+            RouteGuideUtil.getLongitude(feature.getLocation()));
+      } else {
+        appendLogs(
+            logs,
+            "Found no feature at {0}, {1}",
+            RouteGuideUtil.getLatitude(feature.getLocation()),
+            RouteGuideUtil.getLongitude(feature.getLocation()));
+      }
+      return logs.toString();
     }
-    
-    private void disableButtons() {
-        mGetFeatureButton.setEnabled(false);
-        mListFeaturesButton.setEnabled(false);
-        mRecordRouteButton.setEnabled(false);
-        mRouteChatButton.setEnabled(false);
-        mExitRouteGuideButton.setEnabled(false);
+  }
+
+  private static class ListFeaturesRunnable implements GrpcRunnable {
+    @Override
+    public String run(RouteGuideBlockingStub blockingStub, RouteGuideStub asyncStub)
+        throws Exception {
+      return listFeatures(400000000, -750000000, 420000000, -730000000, blockingStub);
     }
-    
-    private void enableButtons() {
-        mExitRouteGuideButton.setEnabled(true);
-        mGetFeatureButton.setEnabled(true);
-        mListFeaturesButton.setEnabled(true);
-        mRecordRouteButton.setEnabled(true);
-        mRouteChatButton.setEnabled(true);
+
+    /**
+     * Blocking server-streaming example. Calls listFeatures with a rectangle of interest. Prints
+     * each response feature as it arrives.
+     */
+    private String listFeatures(
+        int lowLat, int lowLon, int hiLat, int hiLon, RouteGuideBlockingStub blockingStub)
+        throws StatusRuntimeException {
+      StringBuffer logs = new StringBuffer("Result: ");
+      appendLogs(
+          logs,
+          "*** ListFeatures: lowLat={0} lowLon={1} hiLat={2} hiLon={3}",
+          lowLat,
+          lowLon,
+          hiLat,
+          hiLon);
+
+      Rectangle request =
+          Rectangle.newBuilder()
+              .setLo(Point.newBuilder().setLatitude(lowLat).setLongitude(lowLon).build())
+              .setHi(Point.newBuilder().setLatitude(hiLat).setLongitude(hiLon).build())
+              .build();
+      Iterator<Feature> features;
+      features = blockingStub.listFeatures(request);
+
+      while (features.hasNext()) {
+        Feature feature = features.next();
+        appendLogs(logs, feature.toString());
+      }
+      return logs.toString();
     }
+  }
 
-    private class GrpcTask extends AsyncTask<Void, Void, String> {
-        private final GrpcRunnable mGrpc;
+  private static class RecordRouteRunnable implements GrpcRunnable {
+    private Throwable failed;
 
-        GrpcTask(GrpcRunnable grpc) {
-            this.mGrpc = grpc;
-        }
+    @Override
+    public String run(RouteGuideBlockingStub blockingStub, RouteGuideStub asyncStub)
+        throws Exception {
+      List<Point> points = new ArrayList<Point>();
+      points.add(Point.newBuilder().setLatitude(407838351).setLongitude(-746143763).build());
+      points.add(Point.newBuilder().setLatitude(408122808).setLongitude(-743999179).build());
+      points.add(Point.newBuilder().setLatitude(413628156).setLongitude(-749015468).build());
+      return recordRoute(points, 5, asyncStub);
+    }
 
-        @Override
-        protected void onPreExecute() {
-            mResultText.setText("");
-            disableButtons();
-        }
+    /**
+     * Async client-streaming example. Sends {@code numPoints} randomly chosen points from {@code
+     * features} with a variable delay in between. Prints the statistics when they are sent from the
+     * server.
+     */
+    private String recordRoute(List<Point> points, int numPoints, RouteGuideStub asyncStub)
+        throws InterruptedException, RuntimeException {
+      final StringBuffer logs = new StringBuffer();
+      appendLogs(logs, "*** RecordRoute");
+
+      final CountDownLatch finishLatch = new CountDownLatch(1);
+      StreamObserver<RouteSummary> responseObserver =
+          new StreamObserver<RouteSummary>() {
+            @Override
+            public void onNext(RouteSummary summary) {
+              appendLogs(
+                  logs,
+                  "Finished trip with {0} points. Passed {1} features. "
+                      + "Travelled {2} meters. It took {3} seconds.",
+                  summary.getPointCount(),
+                  summary.getFeatureCount(),
+                  summary.getDistance(),
+                  summary.getElapsedTime());
+            }
 
-        @Override
-        protected String doInBackground(Void... nothing) {
-            try {
-                String logs = mGrpc.run(RouteGuideGrpc.newBlockingStub(mChannel),
-                        RouteGuideGrpc.newStub(mChannel));
-                return "Success!" + System.lineSeparator() + logs;
-            } catch (Exception e) {
-                StringWriter sw = new StringWriter();
-                PrintWriter pw = new PrintWriter(sw);
-                e.printStackTrace(pw);
-                pw.flush();
-                return "Failed... : " + System.lineSeparator() + sw;
+            @Override
+            public void onError(Throwable t) {
+              failed = t;
+              finishLatch.countDown();
             }
-        }
 
-        @Override
-        protected void onPostExecute(String result) {
-            mResultText.setText(result);
-            enableButtons();
+            @Override
+            public void onCompleted() {
+              appendLogs(logs, "Finished RecordRoute");
+              finishLatch.countDown();
+            }
+          };
+
+      StreamObserver<Point> requestObserver = asyncStub.recordRoute(responseObserver);
+      try {
+        // Send numPoints points randomly selected from the points list.
+        Random rand = new Random();
+        for (int i = 0; i < numPoints; ++i) {
+          int index = rand.nextInt(points.size());
+          Point point = points.get(index);
+          appendLogs(
+              logs,
+              "Visiting point {0}, {1}",
+              RouteGuideUtil.getLatitude(point),
+              RouteGuideUtil.getLongitude(point));
+          requestObserver.onNext(point);
+          // Sleep for a bit before sending the next one.
+          Thread.sleep(rand.nextInt(1000) + 500);
+          if (finishLatch.getCount() == 0) {
+            // RPC completed or errored before we finished sending.
+            // Sending further requests won't error, but they will just be thrown away.
+            break;
+          }
         }
+      } catch (RuntimeException e) {
+        // Cancel RPC
+        requestObserver.onError(e);
+        throw e;
+      }
+      // Mark the end of requests
+      requestObserver.onCompleted();
+
+      // Receiving happens asynchronously
+      if (!finishLatch.await(1, TimeUnit.MINUTES)) {
+        throw new RuntimeException(
+            "Could not finish rpc within 1 minute, the server is likely down");
+      }
+
+      if (failed != null) {
+        throw new RuntimeException(failed);
+      }
+      return logs.toString();
     }
+  }
 
-    private interface GrpcRunnable {
-        /**
-         * Perform a grpc and return all the logs.
-         */
-        String run(RouteGuideBlockingStub blockingStub, RouteGuideStub asyncStub) throws Exception;
-    }
-
-    private class GetFeatureRunnable implements GrpcRunnable {
-        @Override
-        public String run(RouteGuideBlockingStub blockingStub, RouteGuideStub asyncStub)
-                throws Exception {
-            return getFeature(409146138, -746188906, blockingStub);
-        }
-
-        /**
-         * Blocking unary call example.  Calls getFeature and prints the response.
-         */
-        private String getFeature(int lat, int lon, RouteGuideBlockingStub blockingStub)
-                throws StatusRuntimeException {
-            StringBuffer logs = new StringBuffer();
-            appendLogs(logs, "*** GetFeature: lat={0} lon={1}", lat, lon);
-
-            Point request = Point.newBuilder().setLatitude(lat).setLongitude(lon).build();
-
-            Feature feature;
-            feature = blockingStub.getFeature(request);
-            if (RouteGuideUtil.exists(feature)) {
-                appendLogs(logs, "Found feature called \"{0}\" at {1}, {2}",
-                        feature.getName(),
-                        RouteGuideUtil.getLatitude(feature.getLocation()),
-                        RouteGuideUtil.getLongitude(feature.getLocation()));
-            } else {
-                appendLogs(logs, "Found no feature at {0}, {1}",
-                        RouteGuideUtil.getLatitude(feature.getLocation()),
-                        RouteGuideUtil.getLongitude(feature.getLocation()));
-            }
-            return logs.toString();
-        }    
-    }
+  private static class RouteChatRunnable implements GrpcRunnable {
+    private Throwable failed;
 
-    private class ListFeaturesRunnable implements GrpcRunnable {
-        @Override
-        public String run(RouteGuideBlockingStub blockingStub, RouteGuideStub asyncStub)
-                throws Exception {
-            return listFeatures(400000000, -750000000, 420000000, -730000000, blockingStub);
-        }
-        
-        /**
-         * Blocking server-streaming example. Calls listFeatures with a rectangle of interest.
-         * Prints each response feature as it arrives.
-         */
-        private String listFeatures(int lowLat, int lowLon, int hiLat, int hiLon,
-                RouteGuideBlockingStub blockingStub) throws StatusRuntimeException {
-            StringBuffer logs = new StringBuffer("Result: ");
-            appendLogs(logs, "*** ListFeatures: lowLat={0} lowLon={1} hiLat={2} hiLon={3}",
-                    lowLat, lowLon, hiLat, hiLon);
-
-            Rectangle request = Rectangle.newBuilder()
-                    .setLo(Point.newBuilder().setLatitude(lowLat).setLongitude(lowLon).build())
-                    .setHi(Point.newBuilder().setLatitude(hiLat).setLongitude(hiLon).build())
-                    .build();
-            Iterator<Feature> features;
-            features = blockingStub.listFeatures(request);
-
-            while (features.hasNext()) {
-                Feature feature = features.next();
-                appendLogs(logs, feature.toString());
-            }
-            return logs.toString();
-        }
+    @Override
+    public String run(RouteGuideBlockingStub blockingStub, RouteGuideStub asyncStub)
+        throws Exception {
+      return routeChat(asyncStub);
     }
 
-    private class RecordRouteRunnable implements GrpcRunnable {
-        private Throwable failed;
-
-        @Override
-        public String run(RouteGuideBlockingStub blockingStub, RouteGuideStub asyncStub)
-              throws Exception {
-            List<Point> points = new ArrayList<Point>();
-            points.add(Point.newBuilder()
-                    .setLatitude(407838351).setLongitude(-746143763).build());
-            points.add(Point.newBuilder()
-                    .setLatitude(408122808).setLongitude(-743999179).build());
-            points.add(Point.newBuilder()
-                    .setLatitude(413628156).setLongitude(-749015468).build());
-            return recordRoute(points, 5, asyncStub);
-        }
-        
-        /**
-         * Async client-streaming example. Sends {@code numPoints} randomly chosen points from
-         * {@code features} with a variable delay in between. Prints the statistics when they are
-         * sent from the server.
-         */
-        private String recordRoute(List<Point> points, int numPoints, RouteGuideStub asyncStub)
-                throws InterruptedException, RuntimeException {
-            final StringBuffer logs = new StringBuffer();
-            appendLogs(logs, "*** RecordRoute");
-
-            final CountDownLatch finishLatch = new CountDownLatch(1);
-            StreamObserver<RouteSummary> responseObserver = new StreamObserver<RouteSummary>() {
+    /**
+     * Bi-directional example, which can only be asynchronous. Send some chat messages, and print
+     * any chat messages that are sent from the server.
+     */
+    private String routeChat(RouteGuideStub asyncStub)
+        throws InterruptedException, RuntimeException {
+      final StringBuffer logs = new StringBuffer();
+      appendLogs(logs, "*** RouteChat");
+      final CountDownLatch finishLatch = new CountDownLatch(1);
+      StreamObserver<RouteNote> requestObserver =
+          asyncStub.routeChat(
+              new StreamObserver<RouteNote>() {
                 @Override
-                public void onNext(RouteSummary summary) {
-                    appendLogs(logs, "Finished trip with {0} points. Passed {1} features. "
-                            + "Travelled {2} meters. It took {3} seconds.", summary.getPointCount(),
-                            summary.getFeatureCount(), summary.getDistance(),
-                            summary.getElapsedTime());
+                public void onNext(RouteNote note) {
+                  appendLogs(
+                      logs,
+                      "Got message \"{0}\" at {1}, {2}",
+                      note.getMessage(),
+                      note.getLocation().getLatitude(),
+                      note.getLocation().getLongitude());
                 }
 
                 @Override
                 public void onError(Throwable t) {
-                    failed = t;
-                    finishLatch.countDown();
+                  failed = t;
+                  finishLatch.countDown();
                 }
 
                 @Override
                 public void onCompleted() {
-                    appendLogs(logs, "Finished RecordRoute");
-                    finishLatch.countDown();
-                }
-            };
-
-            StreamObserver<Point> requestObserver = asyncStub.recordRoute(responseObserver);
-            try {
-                // Send numPoints points randomly selected from the points list.
-                Random rand = new Random();
-                for (int i = 0; i < numPoints; ++i) {
-                    int index = rand.nextInt(points.size());
-                    Point point = points.get(index);
-                    appendLogs(logs, "Visiting point {0}, {1}", RouteGuideUtil.getLatitude(point),
-                            RouteGuideUtil.getLongitude(point));
-                    requestObserver.onNext(point);
-                    // Sleep for a bit before sending the next one.
-                    Thread.sleep(rand.nextInt(1000) + 500);
-                    if (finishLatch.getCount() == 0) {
-                        // RPC completed or errored before we finished sending.
-                        // Sending further requests won't error, but they will just be thrown away.
-                        break;
-                    }
-                }
-            } catch (RuntimeException e) {
-                // Cancel RPC
-                requestObserver.onError(e);
-                throw e;
-            }
-            // Mark the end of requests
-            requestObserver.onCompleted();
-
-            // Receiving happens asynchronously
-            if (!finishLatch.await(1, TimeUnit.MINUTES)) {
-                throw new RuntimeException(
-                       "Could not finish rpc within 1 minute, the server is likely down");
-            }
-            
-            if (failed != null) {
-                throw new RuntimeException(failed);
-            }
-            return logs.toString();
-        }
-    }
-
-    private class RouteChatRunnable implements GrpcRunnable {
-        private Throwable failed;
-
-        @Override
-        public String run(RouteGuideBlockingStub blockingStub, RouteGuideStub asyncStub)
-                throws Exception {
-            return routeChat(asyncStub);
-        }
-        
-        /**
-         * Bi-directional example, which can only be asynchronous. Send some chat messages, and
-         * print any chat messages that are sent from the server.
-         */
-        private String routeChat(RouteGuideStub asyncStub) throws InterruptedException,
-                RuntimeException {
-            final StringBuffer logs = new StringBuffer();
-            appendLogs(logs, "*** RouteChat");
-            final CountDownLatch finishLatch = new CountDownLatch(1);
-            StreamObserver<RouteNote> requestObserver =
-                    asyncStub.routeChat(new StreamObserver<RouteNote>() {
-                        @Override
-                        public void onNext(RouteNote note) {
-                            appendLogs(logs, "Got message \"{0}\" at {1}, {2}", note.getMessage(),
-                                    note.getLocation().getLatitude(),
-                                    note.getLocation().getLongitude());
-                        }
-
-                        @Override
-                        public void onError(Throwable t) {
-                            failed = t;
-                            finishLatch.countDown();
-                        }
-
-                        @Override
-                        public void onCompleted() {
-                            appendLogs(logs,"Finished RouteChat");
-                            finishLatch.countDown();
-                        }
-                    });
-
-            try {
-                RouteNote[] requests =
-                        {newNote("First message", 0, 0), newNote("Second message", 0, 1),
-                                newNote("Third message", 1, 0), newNote("Fourth message", 1, 1)};
-
-                for (RouteNote request : requests) {
-                    appendLogs(logs, "Sending message \"{0}\" at {1}, {2}", request.getMessage(),
-                            request.getLocation().getLatitude(),
-                            request.getLocation().getLongitude());
-                    requestObserver.onNext(request);
+                  appendLogs(logs, "Finished RouteChat");
+                  finishLatch.countDown();
                 }
-            } catch (RuntimeException e) {
-                // Cancel RPC
-                requestObserver.onError(e);
-                throw e;
-            }
-            // Mark the end of requests
-            requestObserver.onCompleted();
-
-            // Receiving happens asynchronously
-            if (!finishLatch.await(1, TimeUnit.MINUTES)) {
-                throw new RuntimeException(
-                        "Could not finish rpc within 1 minute, the server is likely down");
-            }
-            
-            if (failed != null) {
-                throw new RuntimeException(failed);
-            }
-
-            return logs.toString();
-        }
-    }
-
-    private static void appendLogs(StringBuffer logs, String msg, Object... params) {
-        if (params.length > 0) {
-            logs.append(MessageFormat.format(msg, params));
-        } else {
-            logs.append(msg);
+              });
+
+      try {
+        RouteNote[] requests = {
+          newNote("First message", 0, 0),
+          newNote("Second message", 0, 1),
+          newNote("Third message", 1, 0),
+          newNote("Fourth message", 1, 1)
+        };
+
+        for (RouteNote request : requests) {
+          appendLogs(
+              logs,
+              "Sending message \"{0}\" at {1}, {2}",
+              request.getMessage(),
+              request.getLocation().getLatitude(),
+              request.getLocation().getLongitude());
+          requestObserver.onNext(request);
         }
-        logs.append(System.lineSeparator());
+      } catch (RuntimeException e) {
+        // Cancel RPC
+        requestObserver.onError(e);
+        throw e;
+      }
+      // Mark the end of requests
+      requestObserver.onCompleted();
+
+      // Receiving happens asynchronously
+      if (!finishLatch.await(1, TimeUnit.MINUTES)) {
+        throw new RuntimeException(
+            "Could not finish rpc within 1 minute, the server is likely down");
+      }
+
+      if (failed != null) {
+        throw new RuntimeException(failed);
+      }
+
+      return logs.toString();
     }
+  }
 
-    private static RouteNote newNote(String message, int lat, int lon) {
-        return RouteNote.newBuilder().setMessage(message)
-                .setLocation(Point.newBuilder().setLatitude(lat).setLongitude(lon).build()).build();
+  private static void appendLogs(StringBuffer logs, String msg, Object... params) {
+    if (params.length > 0) {
+      logs.append(MessageFormat.format(msg, params));
+    } else {
+      logs.append(msg);
     }
+    logs.append("\n");
+  }
+
+  private static RouteNote newNote(String message, int lat, int lon) {
+    return RouteNote.newBuilder()
+        .setMessage(message)
+        .setLocation(Point.newBuilder().setLatitude(lat).setLongitude(lon).build())
+        .build();
+  }
 }
diff --git a/examples/android/routeguide/app/src/main/java/io/grpc/routeguideexample/RouteGuideUtil.java b/examples/android/routeguide/app/src/main/java/io/grpc/routeguideexample/RouteGuideUtil.java
index 6ad13f479..3ef0e5f17 100644
--- a/examples/android/routeguide/app/src/main/java/io/grpc/routeguideexample/RouteGuideUtil.java
+++ b/examples/android/routeguide/app/src/main/java/io/grpc/routeguideexample/RouteGuideUtil.java
@@ -16,36 +16,22 @@
 
 package io.grpc.routeguideexample;
 
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.io.Reader;
-import java.net.URL;
-import java.util.List;
 
-/**
- * Common utilities for the RouteGuide demo.
- */
+/** Common utilities for the RouteGuide demo. */
 public class RouteGuideUtil {
   private static final double COORD_FACTOR = 1e7;
 
-  /**
-   * Gets the latitude for the given point.
-   */
+  /** Gets the latitude for the given point. */
   public static double getLatitude(Point location) {
     return location.getLatitude() / COORD_FACTOR;
   }
 
-  /**
-   * Gets the longitude for the given point.
-   */
+  /** Gets the longitude for the given point. */
   public static double getLongitude(Point location) {
     return location.getLongitude() / COORD_FACTOR;
   }
 
-  /**
-   * Indicates whether the given feature exists (i.e. has a valid name).
-   */
+  /** Indicates whether the given feature exists (i.e. has a valid name). */
   public static boolean exists(Feature feature) {
     return feature != null && !feature.getName().isEmpty();
   }
diff --git a/examples/android/routeguide/app/src/main/res/layout/activity_routeguide.xml b/examples/android/routeguide/app/src/main/res/layout/activity_routeguide.xml
index 4b73bf34a..b76a7a301 100644
--- a/examples/android/routeguide/app/src/main/res/layout/activity_routeguide.xml
+++ b/examples/android/routeguide/app/src/main/res/layout/activity_routeguide.xml
@@ -23,18 +23,18 @@
                 android:hint="Enter Port" />
     </LinearLayout>
 
-    <LinearLayout
+    <LinearLayout style="?android:buttonBarStyle"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"
             android:orientation="horizontal">
-        <Button
+        <Button style="?android:buttonBarButtonStyle"
             android:id="@+id/start_route_guide_button"
             android:layout_weight="1"
             android:layout_width="0dp"
             android:layout_height="wrap_content"
             android:onClick="startRouteGuide"
             android:text="Start Route Guide" />
-        <Button
+        <Button style="?android:buttonBarButtonStyle"
             android:id="@+id/exit_route_guide_button"
             android:layout_weight="1"
             android:layout_width="0dp"
diff --git a/examples/android/routeguide/build.gradle b/examples/android/routeguide/build.gradle
index 316dc9dbb..7b299d637 100644
--- a/examples/android/routeguide/build.gradle
+++ b/examples/android/routeguide/build.gradle
@@ -2,10 +2,11 @@
 
 buildscript {
     repositories {
+        google()
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:2.3.1'
+        classpath 'com.android.tools.build:gradle:3.0.1'
         classpath "com.google.protobuf:protobuf-gradle-plugin:0.8.3"
 
         // NOTE: Do not place your application dependencies here; they belong
@@ -15,6 +16,7 @@ buildscript {
 
 allprojects {
     repositories {
+        google()
         jcenter()
         mavenLocal()
     }