grpc例子 | yjmyzz

grpc是google在github于2015年开源的一款RPC框架，虽然protobuf很早google就开源了，但是google一直没推出正式的开源框架，导致github上基于protobuf的rpc五花八门，国内比较著名的有百度的sofa-pbrpc，但是遗憾的是soft-pbrpc没有对应的java实现版本。rgpc还有一个独立的官网：http://www.grpc.io/，目前已经支持的语言有 C, C++, Java, Go, Node.js, Python, Ruby, Objective-C, PHP 、 C#. grpc最大的特点是基于protobuf + http2 协议，http2协议虽然还未正式定稿，但从目前得知的内容来看，潜力巨大。下面是grpc基本的hello world的示例：

一、grpc-contract

还是按老套路，把服务涉及的对象定义、接口定义抽象出来，下面是项目结构图：

grpc例子-LMLPHP

pom.xml的内容如下：

  1 <?xml version="1.0" encoding="UTF-8"?>

  2 <project xmlns="http://maven.apache.org/POM/4.0.0"

  3          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

  4          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

  5     <modelVersion>4.0.0</modelVersion>

  6

  7     <groupId>yjmyzz.grpc</groupId>

  8     <artifactId>grpc-contract</artifactId>

  9     <version>1.0</version>

 10

 11

 12     <dependencies>

 13

 14         <dependency>

 15             <groupId>junit</groupId>

 16             <artifactId>junit</artifactId>

 17             <version>4.10</version>

 18         </dependency>

 19

 20         <dependency>

 21             <groupId>com.google.protobuf</groupId>

 22             <artifactId>protobuf-java</artifactId>

 23             <version>3.0.0-beta-1</version>

 24         </dependency>

 25

 26         <dependency>

 27             <groupId>io.grpc</groupId>

 28             <artifactId>grpc-all</artifactId>

 29             <version>0.8.0</version>

 30         </dependency>

 31

 32     </dependencies>

 33

 34     <!--下面这个节点可选-->

 35     <pluginRepositories>

 36         <pluginRepository>

 37             <releases>

 38                 <updatePolicy>never</updatePolicy>

 39             </releases>

 40             <snapshots>

 41                 <enabled>false</enabled>

 42             </snapshots>

 43             <id>central</id>

 44             <name>Central Repository</name>

 45             <url>https://repo.maven.apache.org/maven2</url>

 46         </pluginRepository>

 47         <pluginRepository>

 48             <id>protoc-plugin</id>

 49             <url>https://dl.bintray.com/sergei-ivanov/maven/</url>

 50         </pluginRepository>

 51     </pluginRepositories>

 52

 53

 54     <build>

 55         <extensions>

 56             <extension>

 57                 <groupId>kr.motd.maven</groupId>

 58                 <artifactId>os-maven-plugin</artifactId>

 59                 <version>1.4.0.Final</version>

 60             </extension>

 61         </extensions>

 62         <plugins>

 63             <!--用于根据proto文件生成java类的插件-->

 64             <plugin>

 65                 <groupId>com.google.protobuf.tools</groupId>

 66                 <artifactId>maven-protoc-plugin</artifactId>

 67                 <version>0.4.2</version>

 68                 <configuration>

 69                     <protocArtifact>com.google.protobuf:protoc:3.0.0-alpha-3.1:exe:${os.detected.classifier}

 70                     </protocArtifact>

 71                     <pluginId>grpc-java</pluginId>

 72                     <pluginArtifact>io.grpc:protoc-gen-grpc-java:0.8.0:exe:${os.detected.classifier}</pluginArtifact>

 73                 </configuration>

 74                 <executions>

 75                     <execution>

 76                         <goals>

 77                             <goal>compile</goal>

 78                             <goal>compile-custom</goal>

 79                         </goals>

 80                     </execution>

 81                 </executions>

 82             </plugin>

 83

 84             <!--生成源代码jar包的插件（可选）-->

 85             <plugin>

 86                 <artifactId>maven-source-plugin</artifactId>

 87                 <version>2.4</version>

 88                 <executions>

 89                     <execution>

 90                         <phase>package</phase>

 91                         <goals>

 92                             <goal>jar-no-fork</goal>

 93                         </goals>

 94                     </execution>

 95                 </executions>

 96             </plugin>

 97

 98         </plugins>

 99     </build>

100 </project>

demo_service_dto.proto内容如下：

syntax = "proto3";

package yjmyzz.grpc.study.dto;

option java_multiple_files = true;

option java_outer_classname = "DemoServiceDto";

message PingRequest {

     string in=1;

}

message PingResponse {

     string out=1;

}

message QueryParameter {

     int32 ageStart = 1;

     int32 ageEnd = 2;

}

message Person {

     int32 age = 1;

     string name = 2;

     bool sex=3;

     double salary=4;

     int32 childrenCount=5;

}

message PersonList{

     repeated Person items=1;

}

注：grpc要求protobuf必须使用3.0以上版本

demo_service.proto内容如下：

mvn install 后，会自动在target下生成相应的java class类

grpc例子-LMLPHP

二、grpc-server

pom.xml文件如下：

 1 <?xml version="1.0" encoding="UTF-8"?>

 2 <project xmlns="http://maven.apache.org/POM/4.0.0"

 3          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

 4          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

 5     <modelVersion>4.0.0</modelVersion>

 6

 7     <groupId>yjmyzz.grpc</groupId>

 8     <artifactId>grpc-server</artifactId>

 9     <version>1.0</version>

10

11

12     <dependencies>

13         <dependency>

14             <groupId>com.google.protobuf</groupId>

15             <artifactId>protobuf-java</artifactId>

16             <version>3.0.0-beta-1</version>

17         </dependency>

18

19         <dependency>

20             <groupId>yjmyzz.grpc</groupId>

21             <artifactId>grpc-contract</artifactId>

22             <version>1.0</version>

23         </dependency>

24

25         <dependency>

26             <groupId>io.grpc</groupId>

27             <artifactId>grpc-all</artifactId>

28             <version>0.8.0</version>

29         </dependency>

30

31         <dependency>

32             <groupId>junit</groupId>

33             <artifactId>junit</artifactId>

34             <version>4.10</version>

35         </dependency>

36

37     </dependencies>

38

39

40 </project>

先对服务接口提供实现：

package yjmyzz.grpc.study.service.impl;

import io.grpc.stub.StreamObserver;

import yjmyzz.grpc.study.dto.*;

import yjmyzz.grpc.study.service.DemoServiceGrpc;

import java.util.ArrayList;

import java.util.List;

public class DemoServiceImpl implements DemoServiceGrpc.DemoService {

public void ping(PingRequest pingRequest, StreamObserver<PingResponse> streamObserver) {

PingResponse reply = PingResponse.newBuilder().setOut("pong => " + pingRequest.getIn()).build();

streamObserver.onValue(reply);

streamObserver.onCompleted();

}

public void getPersonList(QueryParameter queryParameter, StreamObserver<PersonList> streamObserver) {

//System.out.println(queryParameter.getAgeStart() + "-" + queryParameter.getAgeEnd());

PersonList.Builder personListBuilder = PersonList.newBuilder();

Person.Builder builder = Person.newBuilder();

List<Person> list = new ArrayList<Person>();

for (short i = 0; i < 10; i++) {

list.add(builder.setAge(i).setChildrenCount(i).setName("test" + i).setSex(true).build());

}

personListBuilder.addAllItems(list);

streamObserver.onValue(personListBuilder.build());

streamObserver.onCompleted();

}

和前面thrift、avro的helloworld一样，这里的实现只是意思一下，方便测试而已。

grpc的server端是基于Netty的（当然还有OKHttp的实现，详情见github项目主页），下面是server端的代码：

package yjmyzz.grpc.study.server;

import io.grpc.ServerImpl;

import io.grpc.inprocess.InProcessServerBuilder;

import io.grpc.netty.NettyServerBuilder;

import yjmyzz.grpc.study.service.DemoServiceGrpc;

import yjmyzz.grpc.study.service.impl.DemoServiceImpl;

public class DemoServiceServer {

private int port = 50051;

private ServerImpl server;

private void start() throws Exception {

server = NettyServerBuilder.forPort(port)

.addService(DemoServiceGrpc.bindService(new DemoServiceImpl()))

.build().start();

server = InProcessServerBuilder.forName("testServer")

.addService(DemoServiceGrpc.bindService(new DemoServiceImpl()))

.build().start();

System.out.println("Server started, listening on " + port);

Runtime.getRuntime().addShutdownHook(new Thread() {

@Override

public void run() {

System.out.println("*** shutting down gRPC server since JVM is shutting down");

DemoServiceServer.this.stop();

System.out.println("*** server shut down");

}

});

}

private void stop() {

if (server != null) {

server.shutdown();

}

public static void main(String[] args) throws Exception {

final DemoServiceServer server = new DemoServiceServer();

server.start();

}

三、grpc-client

pom.xml内容：

 1 <?xml version="1.0" encoding="UTF-8"?>

 2 <project xmlns="http://maven.apache.org/POM/4.0.0"

 3          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

 4          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

 5     <modelVersion>4.0.0</modelVersion>

 6

 7     <groupId>yjmyzz.grpc</groupId>

 8     <artifactId>grpc-client</artifactId>

 9     <version>1.0</version>

10

11     <dependencies>

12

13         <dependency>

14             <groupId>com.google.protobuf</groupId>

15             <artifactId>protobuf-java</artifactId>

16             <version>3.0.0-beta-1</version>

17         </dependency>

18

19         <dependency>

20             <groupId>yjmyzz.grpc</groupId>

21             <artifactId>grpc-contract</artifactId>

22             <version>1.0</version>

23         </dependency>

24

25         <dependency>

26             <groupId>io.grpc</groupId>

27             <artifactId>grpc-all</artifactId>

28             <version>0.8.0</version>

29         </dependency>

30

31         <dependency>

32             <groupId>junit</groupId>

33             <artifactId>junit</artifactId>

34             <version>4.10</version>

35         </dependency>

36

37     </dependencies>

38

39 </project>

Client端代码：

package yjmyzz.grpc.study.client;

import io.grpc.ChannelImpl;

import io.grpc.netty.NegotiationType;

import io.grpc.netty.NettyChannelBuilder;

import yjmyzz.grpc.study.dto.PersonList;

import yjmyzz.grpc.study.dto.PingRequest;

import yjmyzz.grpc.study.dto.PingResponse;

import yjmyzz.grpc.study.dto.QueryParameter;

import yjmyzz.grpc.study.service.DemoServiceGrpc;

import java.util.concurrent.TimeUnit;

public class DemoServiceClient {

private final ChannelImpl channel;

private final DemoServiceGrpc.DemoServiceBlockingStub blockingStub;

public DemoServiceClient(String host, int port) {

channel =

NettyChannelBuilder.forAddress(host, port).negotiationType(NegotiationType.PLAINTEXT)

.build();

blockingStub = DemoServiceGrpc.newBlockingStub(channel);

}

public void shutdown() throws InterruptedException {

channel.shutdown().awaitTermination(5, TimeUnit.SECONDS);

}

public void ping(String name) {

try {

System.out.println("Will try to ping " + name + " ...");

PingRequest request = PingRequest.newBuilder().setIn(name).build();

PingResponse response = blockingStub.ping(request);

System.out.println("ping: " + response.getOut());

} catch (RuntimeException e) {

System.out.println("RPC failed:" + e.getMessage());

return;

}

public void getPersonList(QueryParameter parameter) {

try {

//System.out.println("Will try to getPersonList " + parameter + " ...");

PersonList response = blockingStub.getPersonList(parameter);

//System.out.println("items count: " + response.getItemsCount());

// for (Person p : response.getItemsList()) {

// System.out.println(p);

// }

} catch (RuntimeException e) {

System.out.println("RPC failed:" + e.getMessage());

return;

}

public static void main(String[] args) throws Exception {

DemoServiceClient client = new DemoServiceClient("localhost", 50051);

try {

client.ping("a");

int max = 100000;

Long start = System.currentTimeMillis();

for (int i = 0; i < max; i++) {

client.getPersonList(getParameter());

}

Long end = System.currentTimeMillis();

Long elapse = end - start;

int perform = Double.valueOf(max / (elapse / 1000d)).intValue();

System.out.print("rgpc " + max + " 次NettyServer调用，耗时：" + elapse + "毫秒，平均" + perform + "次/秒");

} finally {

client.shutdown();

}

private static QueryParameter getParameter() {

return QueryParameter.newBuilder().setAgeStart(5).setAgeEnd(50).build();

}

在笔记本测试的结果：

Will try to ping a ...
ping: pong => a
rgpc 100000 次NettyServer调用，耗时：36409毫秒，平均2746次/秒

基本上在每秒3k次的数量级，相对thrift（1w+）、avro(5k+)来讲，目前的差距还是很明显的，但是新事物成长总是需要时间，再给google一段时间，相信以后会让大家感到惊艳的。

在序列化方面，也做了一个跟之前thrift、avro类似的测试：

@Test

public void test() throws InvalidProtocolBufferException {

QueryParameter queryParameter = QueryParameter.newBuilder().setAgeStart(1).setAgeEnd(5).build();

byte[] bytes1 = queryParameter.toByteArray();

System.out.println("Protobuf 3.0 二进制序列后的byte数组长度：" + bytes1.length);

QueryParameter result = QueryParameter.parseFrom(bytes1);

System.out.println(queryParameter.getAgeStart() + " - " + result.getAgeStart());

}

输出：

Protobuf 3.0 二进制序列后的byte数组长度：4
1 - 1

在2进制序列化后的大小方面，protobuf 3大体跟thrift的TCompactProtocal（大小5）接近，比avro（大小2）略差。

文中示例源码下载：http://code.taobao.org/svn/grpc-demo/