diff options
author | Stanley Cheung <stanleycheung@google.com> | 2015-08-27 13:53:42 -0700 |
---|---|---|
committer | Stanley Cheung <stanleycheung@google.com> | 2015-08-27 13:53:42 -0700 |
commit | 6905915db1fe4b66e40f03014f7f14c74f3fee16 (patch) | |
tree | 0490cd52ebcaa391df484b84bd947b406bc2b55b /grpc-common/java | |
parent | 209d047db80a2c289fc24b3fafd85945dbcfb543 (diff) |
prepare for move
Diffstat (limited to 'grpc-common/java')
22 files changed, 1411 insertions, 0 deletions
diff --git a/grpc-common/java/android/.gitignore b/grpc-common/java/android/.gitignore new file mode 100644 index 0000000000..6345b76a48 --- /dev/null +++ b/grpc-common/java/android/.gitignore @@ -0,0 +1,21 @@ +.gradle +/local.properties +/gradle.properties +/.idea/workspace.xml +/.idea/libraries +.DS_Store +/build +.idea/ + +*.iml +*.apk +*.ap_ +*.dex +*.class +bin/ +gen/ +.gradle/ +/*/build/ +local.properties +proguard/ +*.log diff --git a/grpc-common/java/android/README.md b/grpc-common/java/android/README.md new file mode 100644 index 0000000000..9de65a0267 --- /dev/null +++ b/grpc-common/java/android/README.md @@ -0,0 +1,41 @@ +gRPC Hello World Tutorial (Android Java) +======================== + +BACKGROUND +------------- +For this sample, we've already generated the server and client stubs from [helloworld.proto](https://github.com/grpc/grpc-common/blob/master/protos/helloworld.proto). + +PREREQUISITES +------------- +- [Java gRPC](https://github.com/grpc/grpc-java) + +- [Android Tutorial](https://developer.android.com/training/basics/firstapp/index.html) if you're new to Android development + +- We only have Android gRPC client in this example. Please follow examples in other languages to build and run a gRPC server. + +INSTALL +------- +**1 Clone the gRPC Java git repo** +```sh +$ git clone https://github.com/grpc/grpc-java +``` + +**2 Install gRPC Java, as described in [How to Build](https://github.com/grpc/grpc-java#how-to-build)** +```sh +$ # from this dir +$ cd grpc-java +$ # follow the instructions in 'How to Build' +``` + +**3 Prepare the app** +- Clone this git repo +```sh +$ git clone https://github.com/grpc/grpc-common + +``` + +**4 Install the app** +```sh +$ cd grpc-common/java/android +$ ./gradlew installDebug +``` diff --git a/grpc-common/java/android/app/.gitignore b/grpc-common/java/android/app/.gitignore new file mode 100644 index 0000000000..796b96d1c4 --- /dev/null +++ b/grpc-common/java/android/app/.gitignore @@ -0,0 +1 @@ +/build diff --git a/grpc-common/java/android/app/build.gradle b/grpc-common/java/android/app/build.gradle new file mode 100644 index 0000000000..aedf4fe92a --- /dev/null +++ b/grpc-common/java/android/app/build.gradle @@ -0,0 +1,34 @@ +apply plugin: 'com.android.application' + +android { + compileSdkVersion 21 + buildToolsVersion "21.1.2" + + defaultConfig { + applicationId "io.grpc.helloworldexample" + minSdkVersion 7 + targetSdkVersion 21 + versionCode 1 + versionName "1.0" + } + buildTypes { + release { + minifyEnabled false + proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' + } + } +} + +dependencies { + compile 'com.android.support:appcompat-v7:21.0.3' + compile 'com.google.code.findbugs:jsr305:3.0.0' + compile 'com.squareup.okhttp:okhttp:2.2.0' + compile 'com.google.guava:guava:18.0' + + // You need to build the https://github.com/grpc/grpc-java + // to obtain these libraries below. + compile 'io.grpc:grpc-core:0.1.0-SNAPSHOT' + compile 'io.grpc:grpc-protobuf-nano:0.1.0-SNAPSHOT' + compile 'io.grpc:grpc-okhttp:0.1.0-SNAPSHOT' + compile 'io.grpc:grpc-stub:0.1.0-SNAPSHOT' +} diff --git a/grpc-common/java/android/app/proguard-rules.pro b/grpc-common/java/android/app/proguard-rules.pro new file mode 100644 index 0000000000..3e659b91f3 --- /dev/null +++ b/grpc-common/java/android/app/proguard-rules.pro @@ -0,0 +1,17 @@ +# Add project specific ProGuard rules here. +# By default, the flags in this file are appended to flags specified +# in /Users/thagikura/android-sdk/tools/proguard/proguard-android.txt +# You can edit the include path and order by changing the proguardFiles +# directive in build.gradle. +# +# For more details, see +# http://developer.android.com/guide/developing/tools/proguard.html + +# Add any project specific keep options here: + +# If your project uses WebView with JS, uncomment the following +# and specify the fully qualified class name to the JavaScript interface +# class: +#-keepclassmembers class fqcn.of.javascript.interface.for.webview { +# public *; +#} diff --git a/grpc-common/java/android/app/src/main/AndroidManifest.xml b/grpc-common/java/android/app/src/main/AndroidManifest.xml new file mode 100644 index 0000000000..8c40f11684 --- /dev/null +++ b/grpc-common/java/android/app/src/main/AndroidManifest.xml @@ -0,0 +1,22 @@ +<?xml version="1.0" encoding="utf-8"?> +<manifest xmlns:android="http://schemas.android.com/apk/res/android" + package="io.grpc.helloworldexample" > + + <uses-permission android:name="android.permission.INTERNET" /> + + <application + android:allowBackup="true" + android:icon="@mipmap/ic_launcher" + android:label="@string/app_name" + android:theme="@style/Base.V7.Theme.AppCompat.Light" > + <activity + android:name=".HelloworldActivity" + android:label="@string/app_name" > + <intent-filter> + <action android:name="android.intent.action.MAIN" /> + <category android:name="android.intent.category.LAUNCHER" /> + </intent-filter> + </activity> + </application> + +</manifest> diff --git a/grpc-common/java/android/app/src/main/java/io/grpc/helloworldexample/GreeterGrpc.java b/grpc-common/java/android/app/src/main/java/io/grpc/helloworldexample/GreeterGrpc.java new file mode 100644 index 0000000000..817c9fde8f --- /dev/null +++ b/grpc-common/java/android/app/src/main/java/io/grpc/helloworldexample/GreeterGrpc.java @@ -0,0 +1,179 @@ +package io.grpc.helloworldexample; + +import java.io.IOException; + +import static io.grpc.stub.Calls.asyncUnaryCall; +import static io.grpc.stub.Calls.blockingUnaryCall; +import static io.grpc.stub.Calls.createMethodDescriptor; +import static io.grpc.stub.Calls.unaryFutureCall; +import static io.grpc.stub.ServerCalls.asyncUnaryRequestCall; +import static io.grpc.stub.ServerCalls.createMethodDefinition; + +public class GreeterGrpc { + + private static final io.grpc.stub.Method<Helloworld.HelloRequest, + Helloworld.HelloReply> METHOD_SAY_HELLO = + io.grpc.stub.Method.create( + io.grpc.MethodType.UNARY, "SayHello", + io.grpc.protobuf.nano.NanoUtils.<Helloworld.HelloRequest>marshaller( + new io.grpc.protobuf.nano.Parser<Helloworld.HelloRequest>() { + @Override + public Helloworld.HelloRequest parse(com.google.protobuf.nano.CodedInputByteBufferNano input) throws IOException { + return Helloworld.HelloRequest.parseFrom(input); + } + }), + io.grpc.protobuf.nano.NanoUtils.<Helloworld.HelloReply>marshaller( + new io.grpc.protobuf.nano.Parser<Helloworld.HelloReply>() { + @Override + public Helloworld.HelloReply parse(com.google.protobuf.nano.CodedInputByteBufferNano input) throws IOException { + return Helloworld.HelloReply.parseFrom(input); + } + })); + + public static GreeterStub newStub(io.grpc.Channel channel) { + return new GreeterStub(channel, CONFIG); + } + + public static GreeterBlockingStub newBlockingStub( + io.grpc.Channel channel) { + return new GreeterBlockingStub(channel, CONFIG); + } + + public static GreeterFutureStub newFutureStub( + io.grpc.Channel channel) { + return new GreeterFutureStub(channel, CONFIG); + } + + public static final GreeterServiceDescriptor CONFIG = + new GreeterServiceDescriptor(); + + public static class GreeterServiceDescriptor extends + io.grpc.stub.AbstractServiceDescriptor<GreeterServiceDescriptor> { + public final io.grpc.MethodDescriptor<Helloworld.HelloRequest, + Helloworld.HelloReply> sayHello; + + private GreeterServiceDescriptor() { + sayHello = createMethodDescriptor( + "helloworld.Greeter", METHOD_SAY_HELLO); + } + + private GreeterServiceDescriptor( + java.util.Map<java.lang.String, io.grpc.MethodDescriptor<?, ?>> methodMap) { + sayHello = (io.grpc.MethodDescriptor<Helloworld.HelloRequest, + Helloworld.HelloReply>) methodMap.get( + CONFIG.sayHello.getName()); + } + + @java.lang.Override + protected GreeterServiceDescriptor build( + java.util.Map<java.lang.String, io.grpc.MethodDescriptor<?, ?>> methodMap) { + return new GreeterServiceDescriptor(methodMap); + } + + @java.lang.Override + public com.google.common.collect.ImmutableList<io.grpc.MethodDescriptor<?, ?>> methods() { + return com.google.common.collect.ImmutableList.<io.grpc.MethodDescriptor<?, ?>>of( + sayHello); + } + } + + public static interface Greeter { + + public void sayHello(Helloworld.HelloRequest request, + io.grpc.stub.StreamObserver<Helloworld.HelloReply> responseObserver); + } + + public static interface GreeterBlockingClient { + + public Helloworld.HelloReply sayHello(Helloworld.HelloRequest request); + } + + public static interface GreeterFutureClient { + + public com.google.common.util.concurrent.ListenableFuture<Helloworld.HelloReply> sayHello( + Helloworld.HelloRequest request); + } + + public static class GreeterStub extends + io.grpc.stub.AbstractStub<GreeterStub, GreeterServiceDescriptor> + implements Greeter { + private GreeterStub(io.grpc.Channel channel, + GreeterServiceDescriptor config) { + super(channel, config); + } + + @java.lang.Override + protected GreeterStub build(io.grpc.Channel channel, + GreeterServiceDescriptor config) { + return new GreeterStub(channel, config); + } + + @java.lang.Override + public void sayHello(Helloworld.HelloRequest request, + io.grpc.stub.StreamObserver<Helloworld.HelloReply> responseObserver) { + asyncUnaryCall( + channel.newCall(config.sayHello), request, responseObserver); + } + } + + public static class GreeterBlockingStub extends + io.grpc.stub.AbstractStub<GreeterBlockingStub, GreeterServiceDescriptor> + implements GreeterBlockingClient { + private GreeterBlockingStub(io.grpc.Channel channel, + GreeterServiceDescriptor config) { + super(channel, config); + } + + @java.lang.Override + protected GreeterBlockingStub build(io.grpc.Channel channel, + GreeterServiceDescriptor config) { + return new GreeterBlockingStub(channel, config); + } + + @java.lang.Override + public Helloworld.HelloReply sayHello(Helloworld.HelloRequest request) { + return blockingUnaryCall( + channel.newCall(config.sayHello), request); + } + } + + public static class GreeterFutureStub extends + io.grpc.stub.AbstractStub<GreeterFutureStub, GreeterServiceDescriptor> + implements GreeterFutureClient { + private GreeterFutureStub(io.grpc.Channel channel, + GreeterServiceDescriptor config) { + super(channel, config); + } + + @java.lang.Override + protected GreeterFutureStub build(io.grpc.Channel channel, + GreeterServiceDescriptor config) { + return new GreeterFutureStub(channel, config); + } + + @java.lang.Override + public com.google.common.util.concurrent.ListenableFuture<Helloworld.HelloReply> sayHello( + Helloworld.HelloRequest request) { + return unaryFutureCall( + channel.newCall(config.sayHello), request); + } + } + + public static io.grpc.ServerServiceDefinition bindService( + final Greeter serviceImpl) { + return io.grpc.ServerServiceDefinition.builder("helloworld.Greeter") + .addMethod(createMethodDefinition( + METHOD_SAY_HELLO, + asyncUnaryRequestCall( + new io.grpc.stub.ServerCalls.UnaryRequestMethod< + Helloworld.HelloRequest, + Helloworld.HelloReply>() { + @java.lang.Override + public void invoke( + Helloworld.HelloRequest request, + io.grpc.stub.StreamObserver<Helloworld.HelloReply> responseObserver) { + serviceImpl.sayHello(request, responseObserver); + } + }))).build(); + } +} diff --git a/grpc-common/java/android/app/src/main/java/io/grpc/helloworldexample/Helloworld.java b/grpc-common/java/android/app/src/main/java/io/grpc/helloworldexample/Helloworld.java new file mode 100644 index 0000000000..28da5a91d3 --- /dev/null +++ b/grpc-common/java/android/app/src/main/java/io/grpc/helloworldexample/Helloworld.java @@ -0,0 +1,175 @@ +// Generated by the protocol buffer compiler. DO NOT EDIT! + +package io.grpc.helloworldexample; + +@SuppressWarnings("hiding") +public interface Helloworld { + + public static final class HelloRequest extends + com.google.protobuf.nano.MessageNano { + + private static volatile HelloRequest[] _emptyArray; + public static HelloRequest[] emptyArray() { + // Lazily initializes the empty array + if (_emptyArray == null) { + synchronized ( + com.google.protobuf.nano.InternalNano.LAZY_INIT_LOCK) { + if (_emptyArray == null) { + _emptyArray = new HelloRequest[0]; + } + } + } + return _emptyArray; + } + + // optional string name = 1; + public java.lang.String name; + + public HelloRequest() { + clear(); + } + + public HelloRequest clear() { + name = ""; + cachedSize = -1; + return this; + } + + @Override + public void writeTo(com.google.protobuf.nano.CodedOutputByteBufferNano output) + throws java.io.IOException { + if (!this.name.equals("")) { + output.writeString(1, this.name); + } + super.writeTo(output); + } + + @Override + protected int computeSerializedSize() { + int size = super.computeSerializedSize(); + if (!this.name.equals("")) { + size += com.google.protobuf.nano.CodedOutputByteBufferNano + .computeStringSize(1, this.name); + } + return size; + } + + @Override + public HelloRequest mergeFrom( + com.google.protobuf.nano.CodedInputByteBufferNano input) + throws java.io.IOException { + while (true) { + int tag = input.readTag(); + switch (tag) { + case 0: + return this; + default: { + if (!com.google.protobuf.nano.WireFormatNano.parseUnknownField(input, tag)) { + return this; + } + break; + } + case 10: { + this.name = input.readString(); + break; + } + } + } + } + + public static HelloRequest parseFrom(byte[] data) + throws com.google.protobuf.nano.InvalidProtocolBufferNanoException { + return com.google.protobuf.nano.MessageNano.mergeFrom(new HelloRequest(), data); + } + + public static HelloRequest parseFrom( + com.google.protobuf.nano.CodedInputByteBufferNano input) + throws java.io.IOException { + return new HelloRequest().mergeFrom(input); + } + } + + public static final class HelloReply extends + com.google.protobuf.nano.MessageNano { + + private static volatile HelloReply[] _emptyArray; + public static HelloReply[] emptyArray() { + // Lazily initializes the empty array + if (_emptyArray == null) { + synchronized ( + com.google.protobuf.nano.InternalNano.LAZY_INIT_LOCK) { + if (_emptyArray == null) { + _emptyArray = new HelloReply[0]; + } + } + } + return _emptyArray; + } + + // optional string message = 1; + public java.lang.String message; + + public HelloReply() { + clear(); + } + + public HelloReply clear() { + message = ""; + cachedSize = -1; + return this; + } + + @Override + public void writeTo(com.google.protobuf.nano.CodedOutputByteBufferNano output) + throws java.io.IOException { + if (!this.message.equals("")) { + output.writeString(1, this.message); + } + super.writeTo(output); + } + + @Override + protected int computeSerializedSize() { + int size = super.computeSerializedSize(); + if (!this.message.equals("")) { + size += com.google.protobuf.nano.CodedOutputByteBufferNano + .computeStringSize(1, this.message); + } + return size; + } + + @Override + public HelloReply mergeFrom( + com.google.protobuf.nano.CodedInputByteBufferNano input) + throws java.io.IOException { + while (true) { + int tag = input.readTag(); + switch (tag) { + case 0: + return this; + default: { + if (!com.google.protobuf.nano.WireFormatNano.parseUnknownField(input, tag)) { + return this; + } + break; + } + case 10: { + this.message = input.readString(); + break; + } + } + } + } + + public static HelloReply parseFrom(byte[] data) + throws com.google.protobuf.nano.InvalidProtocolBufferNanoException { + return com.google.protobuf.nano.MessageNano.mergeFrom(new HelloReply(), data); + } + + public static HelloReply parseFrom( + com.google.protobuf.nano.CodedInputByteBufferNano input) + throws java.io.IOException { + return new HelloReply().mergeFrom(input); + } + } +}
\ No newline at end of file diff --git a/grpc-common/java/android/app/src/main/java/io/grpc/helloworldexample/HelloworldActivity.java b/grpc-common/java/android/app/src/main/java/io/grpc/helloworldexample/HelloworldActivity.java new file mode 100644 index 0000000000..b6d734f9a9 --- /dev/null +++ b/grpc-common/java/android/app/src/main/java/io/grpc/helloworldexample/HelloworldActivity.java @@ -0,0 +1,90 @@ +package io.grpc.helloworldexample; + +import android.content.Context; +import android.os.AsyncTask; +import android.os.Bundle; +import android.support.v7.app.ActionBarActivity; +import android.text.TextUtils; +import android.view.View; +import android.view.inputmethod.InputMethodManager; +import android.widget.Button; +import android.widget.EditText; +import android.widget.TextView; + +import java.util.concurrent.TimeUnit; + +import io.grpc.ChannelImpl; +import io.grpc.helloworldexample.Helloworld.HelloReply; +import io.grpc.helloworldexample.Helloworld.HelloRequest; +import io.grpc.transport.okhttp.OkHttpChannelBuilder; + +public class HelloworldActivity extends ActionBarActivity { + private Button mSendButton; + private EditText mHostEdit; + private EditText mPortEdit; + private EditText mMessageEdit; + private TextView mResultText; + + @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); + } + + public void sendMessage(View view) { + ((InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE)) + .hideSoftInputFromWindow(mHostEdit.getWindowToken(), 0); + mSendButton.setEnabled(false); + new GrpcTask().execute(); + } + + private class GrpcTask extends AsyncTask<Void, Void, String> { + private String mHost; + private String mMessage; + private int mPort; + private ChannelImpl mChannel; + + @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 String sayHello(ChannelImpl channel) { + GreeterGrpc.GreeterBlockingStub stub = GreeterGrpc.newBlockingStub(channel); + HelloRequest message = new HelloRequest(); + message.name = mMessage; + HelloReply reply = stub.sayHello(message); + return reply.message; + } + + @Override + protected String doInBackground(Void... nothing) { + try { + mChannel = OkHttpChannelBuilder.forAddress(mHost, mPort).build(); + return sayHello(mChannel); + } catch (Exception e) { + return "Failed... : " + e.getMessage(); + } + } + + @Override + protected void onPostExecute(String result) { + try { + mChannel.shutdown().awaitTerminated(1, TimeUnit.SECONDS); + } catch (InterruptedException e) { + Thread.currentThread().interrupt(); + } + mResultText.setText(result); + mSendButton.setEnabled(true); + } + } +}
\ No newline at end of file diff --git a/grpc-common/java/android/app/src/main/res/layout/activity_helloworld.xml b/grpc-common/java/android/app/src/main/res/layout/activity_helloworld.xml new file mode 100644 index 0000000000..00ca04ce65 --- /dev/null +++ b/grpc-common/java/android/app/src/main/res/layout/activity_helloworld.xml @@ -0,0 +1,54 @@ +<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" + xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" + android:layout_height="match_parent" + tools:context=".MainActivity" + android:orientation="vertical" > + + <LinearLayout + android:layout_width="match_parent" + android:layout_height="wrap_content" + android:orientation="horizontal"> + <EditText + android:id="@+id/host_edit_text" + android:layout_weight="2" + android:layout_width="0dp" + android:layout_height="wrap_content" + android:hint="Enter Host" /> + <EditText + android:id="@+id/port_edit_text" + android:layout_weight="1" + android:layout_width="0dp" + android:layout_height="wrap_content" + android:inputType="numberDecimal" + android:hint="Enter Port" /> + </LinearLayout> + + + <EditText + android:id="@+id/message_edit_text" + android:layout_width="match_parent" + android:layout_height="wrap_content" + android:hint="Enter message to send" /> + + <Button + android:id="@+id/send_button" + android:layout_width="match_parent" + android:layout_height="wrap_content" + android:onClick="sendMessage" + android:text="Send Grpc Request" /> + + <TextView + android:layout_width="match_parent" + android:layout_height="wrap_content" + android:paddingTop="12dp" + android:paddingBottom="12dp" + android:textSize="16dp" + android:text="Response:" /> + + <TextView + android:id="@+id/grpc_response_text" + android:layout_width="match_parent" + android:layout_height="match_parent" + android:textSize="16dp" /> + +</LinearLayout>
\ No newline at end of file diff --git a/grpc-common/java/android/app/src/main/res/mipmap-hdpi/ic_launcher.png b/grpc-common/java/android/app/src/main/res/mipmap-hdpi/ic_launcher.png Binary files differnew file mode 100644 index 0000000000..cde69bccce --- /dev/null +++ b/grpc-common/java/android/app/src/main/res/mipmap-hdpi/ic_launcher.png diff --git a/grpc-common/java/android/app/src/main/res/mipmap-mdpi/ic_launcher.png b/grpc-common/java/android/app/src/main/res/mipmap-mdpi/ic_launcher.png Binary files differnew file mode 100644 index 0000000000..c133a0cbd3 --- /dev/null +++ b/grpc-common/java/android/app/src/main/res/mipmap-mdpi/ic_launcher.png diff --git a/grpc-common/java/android/app/src/main/res/mipmap-xhdpi/ic_launcher.png b/grpc-common/java/android/app/src/main/res/mipmap-xhdpi/ic_launcher.png Binary files differnew file mode 100644 index 0000000000..bfa42f0e7b --- /dev/null +++ b/grpc-common/java/android/app/src/main/res/mipmap-xhdpi/ic_launcher.png diff --git a/grpc-common/java/android/app/src/main/res/mipmap-xxhdpi/ic_launcher.png b/grpc-common/java/android/app/src/main/res/mipmap-xxhdpi/ic_launcher.png Binary files differnew file mode 100644 index 0000000000..324e72cdd7 --- /dev/null +++ b/grpc-common/java/android/app/src/main/res/mipmap-xxhdpi/ic_launcher.png diff --git a/grpc-common/java/android/app/src/main/res/values/strings.xml b/grpc-common/java/android/app/src/main/res/values/strings.xml new file mode 100644 index 0000000000..64cb312d52 --- /dev/null +++ b/grpc-common/java/android/app/src/main/res/values/strings.xml @@ -0,0 +1,3 @@ +<resources> + <string name="app_name">GrpcHelloworldExample</string> +</resources> diff --git a/grpc-common/java/android/build.gradle b/grpc-common/java/android/build.gradle new file mode 100644 index 0000000000..1bf89c9a52 --- /dev/null +++ b/grpc-common/java/android/build.gradle @@ -0,0 +1,20 @@ +// Top-level build file where you can add configuration options common to all sub-projects/modules. + +buildscript { + repositories { + jcenter() + } + dependencies { + classpath 'com.android.tools.build:gradle:1.1.0' + + // NOTE: Do not place your application dependencies here; they belong + // in the individual module build.gradle files + } +} + +allprojects { + repositories { + jcenter() + mavenLocal() + } +} diff --git a/grpc-common/java/android/gradle/wrapper/gradle-wrapper.jar b/grpc-common/java/android/gradle/wrapper/gradle-wrapper.jar Binary files differnew file mode 100644 index 0000000000..8c0fb64a86 --- /dev/null +++ b/grpc-common/java/android/gradle/wrapper/gradle-wrapper.jar diff --git a/grpc-common/java/android/gradle/wrapper/gradle-wrapper.properties b/grpc-common/java/android/gradle/wrapper/gradle-wrapper.properties new file mode 100644 index 0000000000..0c71e760dc --- /dev/null +++ b/grpc-common/java/android/gradle/wrapper/gradle-wrapper.properties @@ -0,0 +1,6 @@ +#Wed Apr 10 15:27:10 PDT 2013 +distributionBase=GRADLE_USER_HOME +distributionPath=wrapper/dists +zipStoreBase=GRADLE_USER_HOME +zipStorePath=wrapper/dists +distributionUrl=https\://services.gradle.org/distributions/gradle-2.2.1-all.zip diff --git a/grpc-common/java/android/gradlew b/grpc-common/java/android/gradlew new file mode 100755 index 0000000000..91a7e269e1 --- /dev/null +++ b/grpc-common/java/android/gradlew @@ -0,0 +1,164 @@ +#!/usr/bin/env bash + +############################################################################## +## +## Gradle start up script for UN*X +## +############################################################################## + +# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. +DEFAULT_JVM_OPTS="" + +APP_NAME="Gradle" +APP_BASE_NAME=`basename "$0"` + +# Use the maximum available, or set MAX_FD != -1 to use that value. +MAX_FD="maximum" + +warn ( ) { + echo "$*" +} + +die ( ) { + echo + echo "$*" + echo + exit 1 +} + +# OS specific support (must be 'true' or 'false'). +cygwin=false +msys=false +darwin=false +case "`uname`" in + CYGWIN* ) + cygwin=true + ;; + Darwin* ) + darwin=true + ;; + MINGW* ) + msys=true + ;; +esac + +# For Cygwin, ensure paths are in UNIX format before anything is touched. +if $cygwin ; then + [ -n "$JAVA_HOME" ] && JAVA_HOME=`cygpath --unix "$JAVA_HOME"` +fi + +# Attempt to set APP_HOME +# Resolve links: $0 may be a link +PRG="$0" +# Need this for relative symlinks. +while [ -h "$PRG" ] ; do + ls=`ls -ld "$PRG"` + link=`expr "$ls" : '.*-> \(.*\)$'` + if expr "$link" : '/.*' > /dev/null; then + PRG="$link" + else + PRG=`dirname "$PRG"`"/$link" + fi +done +SAVED="`pwd`" +cd "`dirname \"$PRG\"`/" >&- +APP_HOME="`pwd -P`" +cd "$SAVED" >&- + +CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar + +# Determine the Java command to use to start the JVM. +if [ -n "$JAVA_HOME" ] ; then + if [ -x "$JAVA_HOME/jre/sh/java" ] ; then + # IBM's JDK on AIX uses strange locations for the executables + JAVACMD="$JAVA_HOME/jre/sh/java" + else + JAVACMD="$JAVA_HOME/bin/java" + fi + if [ ! -x "$JAVACMD" ] ; then + die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME + +Please set the JAVA_HOME variable in your environment to match the +location of your Java installation." + fi +else + JAVACMD="java" + which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. + +Please set the JAVA_HOME variable in your environment to match the +location of your Java installation." +fi + +# Increase the maximum file descriptors if we can. +if [ "$cygwin" = "false" -a "$darwin" = "false" ] ; then + MAX_FD_LIMIT=`ulimit -H -n` + if [ $? -eq 0 ] ; then + if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then + MAX_FD="$MAX_FD_LIMIT" + fi + ulimit -n $MAX_FD + if [ $? -ne 0 ] ; then + warn "Could not set maximum file descriptor limit: $MAX_FD" + fi + else + warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT" + fi +fi + +# For Darwin, add options to specify how the application appears in the dock +if $darwin; then + GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\"" +fi + +# For Cygwin, switch paths to Windows format before running java +if $cygwin ; then + APP_HOME=`cygpath --path --mixed "$APP_HOME"` + CLASSPATH=`cygpath --path --mixed "$CLASSPATH"` + + # We build the pattern for arguments to be converted via cygpath + ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null` + SEP="" + for dir in $ROOTDIRSRAW ; do + ROOTDIRS="$ROOTDIRS$SEP$dir" + SEP="|" + done + OURCYGPATTERN="(^($ROOTDIRS))" + # Add a user-defined pattern to the cygpath arguments + if [ "$GRADLE_CYGPATTERN" != "" ] ; then + OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)" + fi + # Now convert the arguments - kludge to limit ourselves to /bin/sh + i=0 + for arg in "$@" ; do + CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -` + CHECK2=`echo "$arg"|egrep -c "^-"` ### Determine if an option + + if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then ### Added a condition + eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"` + else + eval `echo args$i`="\"$arg\"" + fi + i=$((i+1)) + done + case $i in + (0) set -- ;; + (1) set -- "$args0" ;; + (2) set -- "$args0" "$args1" ;; + (3) set -- "$args0" "$args1" "$args2" ;; + (4) set -- "$args0" "$args1" "$args2" "$args3" ;; + (5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;; + (6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;; + (7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;; + (8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;; + (9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;; + esac +fi + +# Split up the JVM_OPTS And GRADLE_OPTS values into an array, following the shell quoting and substitution rules +function splitJvmOpts() { + JVM_OPTS=("$@") +} +eval splitJvmOpts $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS +JVM_OPTS[${#JVM_OPTS[*]}]="-Dorg.gradle.appname=$APP_BASE_NAME" + +exec "$JAVACMD" "${JVM_OPTS[@]}" -classpath "$CLASSPATH" org.gradle.wrapper.GradleWrapperMain "$@" diff --git a/grpc-common/java/android/gradlew.bat b/grpc-common/java/android/gradlew.bat new file mode 100644 index 0000000000..aec99730b4 --- /dev/null +++ b/grpc-common/java/android/gradlew.bat @@ -0,0 +1,90 @@ +@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS=
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windowz variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+if "%@eval[2+2]" == "4" goto 4NT_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+goto execute
+
+:4NT_args
+@rem Get arguments from the 4NT Shell from JP Software
+set CMD_LINE_ARGS=%$
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/grpc-common/java/android/settings.gradle b/grpc-common/java/android/settings.gradle new file mode 100644 index 0000000000..e7b4def49c --- /dev/null +++ b/grpc-common/java/android/settings.gradle @@ -0,0 +1 @@ +include ':app' diff --git a/grpc-common/java/javatutorial.md b/grpc-common/java/javatutorial.md new file mode 100644 index 0000000000..7e305a14d5 --- /dev/null +++ b/grpc-common/java/javatutorial.md @@ -0,0 +1,493 @@ +#gRPC Basics: Java + +This tutorial provides a basic Java programmer's introduction to working with gRPC. By walking through this example you'll learn how to: + +- Define a service in a .proto file. +- Generate server and client code using the protocol buffer compiler. +- Use the Java gRPC API to write a simple client and server for your service. + +It assumes that you have read the [Getting started](https://github.com/grpc/grpc-common) guide and are familiar with [protocol buffers] (https://developers.google.com/protocol-buffers/docs/overview). Note that the example in this tutorial uses the [proto3](https://github.com/google/protobuf/releases) version of the protocol buffers language, which is currently in alpha release: you can find out more in the [proto3 language guide](https://developers.google.com/protocol-buffers/docs/proto3) and see the [release notes](https://github.com/google/protobuf/releases) for the new version in the protocol buffers Github repository. + +This isn't a comprehensive guide to using gRPC in Java: more reference documentation is coming soon. + +## Why use gRPC? + +Our example is a simple route mapping application that lets clients get information about features on their route, create a summary of their route, and exchange route information such as traffic updates with the server and other clients. + +With gRPC we can define our service once in a .proto file and implement clients and servers in any of gRPC's supported languages, which in turn can be run in environments ranging from servers inside Google to your own tablet - all the complexity of communication between different languages and environments is handled for you by gRPC. We also get all the advantages of working with protocol buffers, including efficient serialization, a simple IDL, and easy interface updating. + +## Example code and setup + +The example code for our tutorial is in [grpc/grpc-java/examples/src/main/java/io/grpc/examples](https://github.com/grpc/grpc-java/tree/master/examples/src/main/java/io/grpc/examples). To download the example, clone the `grpc-java` repository by running the following command: +```shell +$ git clone https://github.com/grpc/grpc-java.git +``` + +Then change your current directory to `grpc-java/examples`: +```shell +$ cd grpc-java/examples +``` + +You also should have the relevant tools installed to generate the server and client interface code - if you don't already, follow the setup instructions in [the Java quick start guide](https://github.com/grpc/grpc-common/tree/master/java). + + +## Defining the service + +Our first step (as you'll know from [Getting started](https://github.com/grpc/grpc-common)) is to define the gRPC *service* and the method *request* and *response* types using [protocol buffers] (https://developers.google.com/protocol-buffers/docs/overview). You can see the complete .proto file in [`grpc-java/examples/src/main/proto/route_guide.proto`](https://github.com/grpc/grpc-java/blob/master/examples/src/main/proto/route_guide.proto). + +As we're generating Java code in this example, we've specified a `java_package` file option in our .proto: +```proto +option java_package = "io.grpc.examples"; +``` + +This specifies the package we want to use for our generated Java classes. If no explicit `java_package` option is given in the .proto file, then by default the proto package (specified using the "package" keyword) will be used. However, proto packages generally do not make good Java packages since proto packages are not expected to start with reverse domain names. If we generate code in another language from this .proto, the `java_package` option has no effect. + +To define a service, we specify a named `service` in the .proto file: + +```proto +service RouteGuide { + ... +} +``` + +Then we define `rpc` methods inside our service definition, specifying their request and response types. gRPC lets you define four kinds of service method, all of which are used in the `RouteGuide` service: + +- A *simple RPC* where the client sends a request to the server using the stub and waits for a response to come back, just like a normal function call. +```proto + // Obtains the feature at a given position. + rpc GetFeature(Point) returns (Feature) {} +``` + +- A *server-side streaming RPC* where the client sends a request to the server and gets a stream to read a sequence of messages back. The client reads from the returned stream until there are no more messages. As you can see in our example, you specify a server-side streaming method by placing the `stream` keyword before the *response* type. +```proto + // Obtains the Features available within the given Rectangle. Results are + // streamed rather than returned at once (e.g. in a response message with a + // repeated field), as the rectangle may cover a large area and contain a + // huge number of features. + rpc ListFeatures(Rectangle) returns (stream Feature) {} +``` + +- A *client-side streaming RPC* where the client writes a sequence of messages and sends them to the server, again using a provided stream. Once the client has finished writing the messages, it waits for the server to read them all and return its response. You specify a server-side streaming method by placing the `stream` keyword before the *request* type. +```proto + // Accepts a stream of Points on a route being traversed, returning a + // RouteSummary when traversal is completed. + rpc RecordRoute(stream Point) returns (RouteSummary) {} +``` + +- A *bidirectional streaming RPC* where both sides send a sequence of messages using a read-write stream. The two streams operate independently, so clients and servers can read and write in whatever order they like: for example, the server could wait to receive all the client messages before writing its responses, or it could alternately read a message then write a message, or some other combination of reads and writes. The order of messages in each stream is preserved. You specify this type of method by placing the `stream` keyword before both the request and the response. +```proto + // Accepts a stream of RouteNotes sent while a route is being traversed, + // while receiving other RouteNotes (e.g. from other users). + rpc RouteChat(stream RouteNote) returns (stream RouteNote) {} +``` + +Our .proto file also contains protocol buffer message type definitions for all the request and response types used in our service methods - for example, here's the `Point` message type: +```proto +// Points are represented as latitude-longitude pairs in the E7 representation +// (degrees multiplied by 10**7 and rounded to the nearest integer). +// Latitudes should be in the range +/- 90 degrees and longitude should be in +// the range +/- 180 degrees (inclusive). +message Point { + int32 latitude = 1; + int32 longitude = 2; +} +``` + + +## Generating client and server code + +Next we need to generate the gRPC client and server interfaces from our .proto service definition. We do this using the protocol buffer compiler `protoc` with a special gRPC Java plugin. You need to use the [proto3](https://github.com/google/protobuf/releases) compiler in order to generate gRPC services + +For simplicity, we've provided a [Gradle build file](https://github.com/grpc/grpc-java/blob/master/examples/build.gradle) that runs `protoc` for you with the appropriate plugin, input, and output (if you want to run this yourself, make sure you've installed protoc and followed the gRPC code [installation instructions](https://github.com/grpc/grpc-java) first): + +```shell +../gradlew build +``` + +which actually runs: + +```shell +protoc -I examples/src/main/proto -I examples/build/extracted-protos/main --java_out=examples/build/generated-sources/main --java_plugin_out=examples/build/generated-sources/main --plugin=protoc-gen-java_plugin=compiler/build/binaries/java_pluginExecutable/java_plugin examples/src/main/proto/route_guide.proto +``` + +Running this command generates the following files: +- `RouteGuideOuterClass.java`, which contains all the protocol buffer code to populate, serialize, and retrieve our request and response message types +- `RouteGuideGrpc.java` which contains (along with some other useful code): + - an interface for `RouteGuide` servers to implement, `RouteGuideGrpc.Service`, with all the methods defined in the `RouteGuide` service. + - *stub* classes that clients can use to talk to a `RouteGuide` server. These also implement the `RouteGuide` interface. + + +<a name="server"></a> +## Creating the server + +First let's look at how we create a `RouteGuide` server. If you're only interested in creating gRPC clients, you can skip this section and go straight to [Creating the client](#client) (though you might find it interesting anyway!). + +There are two parts to making our `RouteGuide` service do its job: +- Implementing the service interface generated from our service definition: doing the actual "work" of our service. +- Running a gRPC server to listen for requests from clients and return the service responses. + +You can find our example `RouteGuide` server in [grpc-java/examples/src/main/java/io/grpc/examples/RouteGuideServer.java](https://github.com/grpc/grpc-java/blob/master/examples/src/main/java/io/grpc/examples/RouteGuideServer.java). Let's take a closer look at how it works. + +### Implementing RouteGuide + +As you can see, our server has a `RouteGuideService` class that implements the generated `RouteGuideGrpc.Service` interface: + +```java +private static class RouteGuideService implements RouteGuideGrpc.RouteGuide { +... +} +``` +#### Simple RPC +`RouteGuideService` implements all our service methods. Let's look at the simplest type first, `GetFeature`, which just gets a `Point` from the client and returns the corresponding feature information from its database in a `Feature`. + +```java + @Override + public void getFeature(Point request, StreamObserver<Feature> responseObserver) { + responseObserver.onValue(getFeature(request)); + responseObserver.onCompleted(); + } + +... + + private Feature getFeature(Point location) { + for (Feature feature : features) { + if (feature.getLocation().getLatitude() == location.getLatitude() + && feature.getLocation().getLongitude() == location.getLongitude()) { + return feature; + } + } + + // No feature was found, return an unnamed feature. + return Feature.newBuilder().setName("").setLocation(location).build(); + } +``` + +`getFeature()` takes two parameters: +- `Point`: the request +- `StreamObserver<Feature>`: a response observer, which is a special interface for the server to call with its response. + +To return our response to the client and complete the call: + +1. We construct and populate a `Feature` response object to return to the client, as specified in our service definition. In this example, we do this in a separate private `getFeature()` method. +2. We use the response observer's `onValue()` method to return the `Feature`. +3. We use the response observer's `onCompleted()` method to specify that we've finished dealing with the RPC. + +#### Server-side streaming RPC +Next let's look at one of our streaming RPCs. `ListFeatures` is a server-side streaming RPC, so we need to send back multiple `Feature`s to our client. + +```java +private final Collection<Feature> features; + +... + + @Override + public void listFeatures(Rectangle request, StreamObserver<Feature> responseObserver) { + int left = min(request.getLo().getLongitude(), request.getHi().getLongitude()); + int right = max(request.getLo().getLongitude(), request.getHi().getLongitude()); + int top = max(request.getLo().getLatitude(), request.getHi().getLatitude()); + int bottom = min(request.getLo().getLatitude(), request.getHi().getLatitude()); + + for (Feature feature : features) { + if (!RouteGuideUtil.exists(feature)) { + continue; + } + + int lat = feature.getLocation().getLatitude(); + int lon = feature.getLocation().getLongitude(); + if (lon >= left && lon <= right && lat >= bottom && lat <= top) { + responseObserver.onValue(feature); + } + } + responseObserver.onCompleted(); + } +``` + +Like the simple RPC, this method gets a request object (the `Rectangle` in which our client wants to find `Feature`s) and a `StreamObserver` response observer. + +This time, we get as many `Feature` objects as we need to return to the client (in this case, we select them from the service's feature collection based on whether they're inside our request `Rectangle`), and write them each in turn to the response observer using its `Write()` method. Finally, as in our simple RPC, we use the response observer's `onCompleted()` method to tell gRPC that we've finished writing responses. + +#### Client-side streaming RPC +Now let's look at something a little more complicated: the client-side streaming method `RecordRoute`, where we get a stream of `Point`s from the client and return a single `RouteSummary` with information about their trip. + +```java + @Override + public StreamObserver<Point> recordRoute(final StreamObserver<RouteSummary> responseObserver) { + return new StreamObserver<Point>() { + int pointCount; + int featureCount; + int distance; + Point previous; + long startTime = System.nanoTime(); + + @Override + public void onValue(Point point) { + pointCount++; + if (RouteGuideUtil.exists(getFeature(point))) { + featureCount++; + } + // For each point after the first, add the incremental distance from the previous point to + // the total distance value. + if (previous != null) { + distance += calcDistance(previous, point); + } + previous = point; + } + + @Override + public void onError(Throwable t) { + logger.log(Level.WARNING, "Encountered error in recordRoute", t); + } + + @Override + public void onCompleted() { + long seconds = NANOSECONDS.toSeconds(System.nanoTime() - startTime); + responseObserver.onValue(RouteSummary.newBuilder().setPointCount(pointCount) + .setFeatureCount(featureCount).setDistance(distance) + .setElapsedTime((int) seconds).build()); + responseObserver.onCompleted(); + } + }; + } +``` + +As you can see, like the previous method types our method gets a `StreamObserver` response observer parameter, but this time it returns a `StreamObserver` for the client to write its `Point`s. + +In the method body we instantiate an anonymous `StreamObserver` to return, in which we: +- Override the `onValue()` method to get features and other information each time the client writes a `Point` to the message stream. +- Override the `onCompleted()` method (called when the *client* has finished writing messages) to populate and build our `RouteSummary`. We then call our method's own response observer's `onValue()` with our `RouteSummary`, and then call its `onCompleted()` method to finish the call from the server side. + +#### Bidirectional streaming RPC +Finally, let's look at our bidirectional streaming RPC `RouteChat()`. + +```cpp + @Override + public StreamObserver<RouteNote> routeChat(final StreamObserver<RouteNote> responseObserver) { + return new StreamObserver<RouteNote>() { + @Override + public void onValue(RouteNote note) { + List<RouteNote> notes = getOrCreateNotes(note.getLocation()); + + // Respond with all previous notes at this location. + for (RouteNote prevNote : notes.toArray(new RouteNote[0])) { + responseObserver.onValue(prevNote); + } + + // Now add the new note to the list + notes.add(note); + } + + @Override + public void onError(Throwable t) { + logger.log(Level.WARNING, "Encountered error in routeChat", t); + } + + @Override + public void onCompleted() { + responseObserver.onCompleted(); + } + }; + } +``` + +As with our client-side streaming example, we both get and return a `StreamObserver` response observer, except this time we return values via our method's response observer while the client is still writing messages to *their* message stream. The syntax for reading and writing here is exactly the same as for our client-streaming and server-streaming methods. Although each side will always get the other's messages in the order they were written, both the client and server can read and write in any order — the streams operate completely independently. + +### Starting the server + +Once we've implemented all our methods, we also need to start up a gRPC server so that clients can actually use our service. The following snippet shows how we do this for our `RouteGuide` service: + +```java + public void start() { + gRpcServer = NettyServerBuilder.forPort(port) + .addService(RouteGuideGrpc.bindService(new RouteGuideService(features))) + .build().start(); + logger.info("Server started, listening on " + port); + ... + } +``` +As you can see, we build and start our server using a `NettyServerBuilder`. This is a builder for servers based on the [Netty](http://netty.io/) transport framework. + +To do this, we: + +1. Create an instance of our service implementation class `RouteGuideService` and pass it to the generated `RouteGuideGrpc` class's static `bindService()` method to get a service definition. +3. Specify the address and port we want to use to listen for client requests using the builder's `forPort()` method. +4. Register our service implementation with the builder by passing the service definition returned from `bindService()` to the builder's `addService()` method. +5. Call `build()` and `start()` on the builder to create and start an RPC server for our service. + +<a name="client"></a> +## Creating the client + +In this section, we'll look at creating a Java client for our `RouteGuide` service. You can see our complete example client code in [grpc-java/examples/src/main/java/io/grpc/examples/RouteGuideClient.java](https://github.com/grpc/grpc-java/blob/master/examples/src/main/java/io/grpc/examples/RouteGuideClient.java). + +### Creating a stub + +To call service methods, we first need to create a *stub*, or rather, two stubs: +- a *blocking/synchronous* stub: this means that the RPC call waits for the server to respond, and will either return a response or raise an exception. +- a *non-blocking/asynchronous* stub that makes non-blocking calls to the server, where the response is returned asynchronously. You can make certain types of streaming call only using the asynchronous stub. + +First we need to create a gRPC *channel* for our stub, specifying the server address and port we want to connect to: + +```java + channel = NettyChannelBuilder.forAddress(host, port) + .negotiationType(NegotiationType.PLAINTEXT) + .build(); +``` + +As with our server, we're using the [Netty](http://netty.io/) transport framework, so we use a `NettyChannelBuilder`. + +Now we can use the channel to create our stubs using the `newStub` and `newBlockingStub` methods provided in the `RouteGuideGrpc` class we generated from our .proto. + +```java + blockingStub = RouteGuideGrpc.newBlockingStub(channel); + asyncStub = RouteGuideGrpc.newStub(channel); +``` + +### Calling service methods + +Now let's look at how we call our service methods. + +#### Simple RPC + +Calling the simple RPC `GetFeature` on the blocking stub is as straightforward as calling a local method. + +```java + Point request = Point.newBuilder().setLatitude(lat).setLongitude(lon).build(); + Feature feature = blockingStub.getFeature(request); +``` + +We create and populate a request protocol buffer object (in our case `Point`), pass it to the `getFeature()` method on our blocking stub, and get back a `Feature`. + +#### Server-side streaming RPC + +Next, let's look at a server-side streaming call to `ListFeatures`, which returns a stream of geographical `Feature`s: + +```java + Rectangle request = + Rectangle.newBuilder() + .setLo(Point.newBuilder().setLatitude(lowLat).setLongitude(lowLon).build()) + .setHi(Point.newBuilder().setLatitude(hiLat).setLongitude(hiLon).build()).build(); + Iterator<Feature> features = blockingStub.listFeatures(request); +``` + +As you can see, it's very similar to the simple RPC we just looked at, except instead of returning a single `Feature`, the method returns an `Iterator` that the client can use to read all the returned `Feature`s. + +#### Client-side streaming RPC + +Now for something a little more complicated: the client-side streaming method `RecordRoute`, where we send a stream of `Point`s to the server and get back a single `RouteSummary`. For this method we need to use the asynchronous stub. If you've already read [Creating the server](#server) some of this may look very familiar - asynchronous streaming RPCs are implemented in a similar way on both sides. + +```java + public void recordRoute(List<Feature> features, int numPoints) throws Exception { + info("*** RecordRoute"); + final SettableFuture<Void> finishFuture = SettableFuture.create(); + StreamObserver<RouteSummary> responseObserver = new StreamObserver<RouteSummary>() { + @Override + public void onValue(RouteSummary summary) { + info("Finished trip with {0} points. Passed {1} features. " + + "Travelled {2} meters. It took {3} seconds.", summary.getPointCount(), + summary.getFeatureCount(), summary.getDistance(), summary.getElapsedTime()); + } + + @Override + public void onError(Throwable t) { + finishFuture.setException(t); + } + + @Override + public void onCompleted() { + finishFuture.set(null); + } + }; + + StreamObserver<Point> requestObserver = asyncStub.recordRoute(responseObserver); + try { + // Send numPoints points randomly selected from the features list. + StringBuilder numMsg = new StringBuilder(); + Random rand = new Random(); + for (int i = 0; i < numPoints; ++i) { + int index = rand.nextInt(features.size()); + Point point = features.get(index).getLocation(); + info("Visiting point {0}, {1}", RouteGuideUtil.getLatitude(point), + RouteGuideUtil.getLongitude(point)); + requestObserver.onValue(point); + // Sleep for a bit before sending the next one. + Thread.sleep(rand.nextInt(1000) + 500); + if (finishFuture.isDone()) { + break; + } + } + info(numMsg.toString()); + requestObserver.onCompleted(); + + finishFuture.get(); + info("Finished RecordRoute"); + } catch (Exception e) { + requestObserver.onError(e); + logger.log(Level.WARNING, "RecordRoute Failed", e); + throw e; + } + } +``` + +As you can see, to call this method we need to create a `StreamObserver`, which implements a special interface for the server to call with its `RouteSummary` response. In our `StreamObserver` we: +- Override the `onValue()` method to print out the returned information when the server writes a `RouteSummary` to the message stream. +- Override the `onCompleted()` method (called when the *server* has completed the call on its side) to set a `SettableFuture` that we can check to see if the server has finished writing. + +We then pass the `StreamObserver` to the asynchronous stub's `recordRoute()` method and get back our own `StreamObserver` request observer to write our `Point`s to send to the server. Once we've finished writing points, we use the request observer's `onCompleted()` method to tell gRPC that we've finished writing on the client side. Once we're done, we check our `SettableFuture` to check that the server has completed on its side. + +#### Bidirectional streaming RPC + +Finally, let's look at our bidirectional streaming RPC `RouteChat()`. + +```java + public void routeChat() throws Exception { + info("*** RoutChat"); + final SettableFuture<Void> finishFuture = SettableFuture.create(); + StreamObserver<RouteNote> requestObserver = + asyncStub.routeChat(new StreamObserver<RouteNote>() { + @Override + public void onValue(RouteNote note) { + info("Got message \"{0}\" at {1}, {2}", note.getMessage(), note.getLocation() + .getLatitude(), note.getLocation().getLongitude()); + } + + @Override + public void onError(Throwable t) { + finishFuture.setException(t); + } + + @Override + public void onCompleted() { + finishFuture.set(null); + } + }); + + 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) { + info("Sending message \"{0}\" at {1}, {2}", request.getMessage(), request.getLocation() + .getLatitude(), request.getLocation().getLongitude()); + requestObserver.onValue(request); + } + requestObserver.onCompleted(); + + finishFuture.get(); + info("Finished RouteChat"); + } catch (Exception t) { + requestObserver.onError(t); + logger.log(Level.WARNING, "RouteChat Failed", t); + throw t; + } + } +``` + +As with our client-side streaming example, we both get and return a `StreamObserver` response observer, except this time we send values via our method's response observer while the server is still writing messages to *their* message stream. The syntax for reading and writing here is exactly the same as for our client-streaming method. Although each side will always get the other's messages in the order they were written, both the client and server can read and write in any order — the streams operate completely independently. + + +## Try it out! + +Follow the instructions in the example directory [README](https://github.com/grpc/grpc-java/blob/master/examples/README.md) to build and run the client and server. + + + |