Check-in date (2019-07-18)
learning points
- 利用grpc完成Bidirectional Streaming RPC例子
step
- 1. Configure the grpc dependency package
- 2. Write the proto file
- 3. Use gradle generateProto to generate java classes
- 4. Write Server/Client service
Note: The server should only be responsible for starting, so the Server class reuses the previous chapter
"Netty Learning Punching Cards - From Little White to Giving Up" ----- 15 - netty's grpc Simple RPC example
2. Write the proto file
syntax = "proto3";
package study;
option java_package = "com.dragon.study";
option java_outer_classname = "Student";
option optimize_for = SPEED;
option java_multiple_files = true;
message StreamRequest{
string message = 1;
}
message StreamResponse{
string username = 1;
string address = 2;
int32 phone = 3;
}
service StudentService{
rpc getAllUser(stream StreamRequest) returns (stream StreamResponse){}
}
3. Use gradle generateProto to generate java classes
运行命令:
gradle generateProto
4. Write Server/Client service
Server
The server side is the same as the previous chapter
"Netty Learning to Punch Cards - from Xiaobai to Giving Up" ----- 15 - netty's grpc Simple RPC example
package com.dragon.study.server;
import com.dragon.study.*;
import io.grpc.stub.StreamObserver;
import java.util.ArrayList;
import java.util.List;
public class StudentServiceImpl extends StudentServiceGrpc.StudentServiceImplBase {
@Override
public StreamObserver<StreamRequest> getAllUser(StreamObserver<StreamResponse> responseObserver) {
StreamObserver<StreamRequest> streamObserver = new StreamObserver<StreamRequest>() {
@Override
public void onNext(StreamRequest value) {
System.out.println("接收到客户端请求的参数 SreamRequest.message = " + value.getMessage());
responseObserver.onNext(StreamResponse.newBuilder().setAddress("北京").setPhone(123).setUsername("王八犊子《"+value.getMessage()+"》").build());
}
@Override
public void onError(Throwable t) {
}
@Override
public void onCompleted() {
responseObserver.onCompleted();
}
};
return streamObserver;
}
}
Client
package com.dragon.study.client;
import com.dragon.study.*;
import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;
import io.grpc.stub.StreamObserver;
import java.util.Iterator;
import java.util.concurrent.TimeUnit;
import java.util.logging.Logger;
public class StudentClient {
private static final Logger logger = Logger.getLogger(StudentClient.class.getName());
//channel相当于一个连接，客户端核心类
private final ManagedChannel channel;
//当请求是不是stream流的时候，使用阻塞式stub就可以
private final StudentServiceGrpc.StudentServiceBlockingStub blockingStub;
//需要指出一点，当请求是stream流的时候，就需要使用异步的请求方式去请求服务
private final StudentServiceGrpc.StudentServiceStub stub;
public StudentClient(String host , int port){
//ManagedChannelBuilder 管理客户端的链接，用来创建链接
this(ManagedChannelBuilder.forAddress(host,port).usePlaintext().build());
}
public StudentClient(ManagedChannel channel) {
this.channel = channel;
blockingStub = StudentServiceGrpc.newBlockingStub(channel);
stub = StudentServiceGrpc.newStub(channel);
}
public void shutdown() throws InterruptedException {
channel.shutdown().awaitTermination(100,TimeUnit.SECONDS);
}
public void getStreamUser(){
StreamObserver<StreamRequest> requestStreamObserver = stub.getAllUser(new StreamObserver<StreamResponse>() {
//收到服务器端的返回的结果
@Override
public void onNext(StreamResponse value) {
System.out.println(value.getUsername() + "," + value.getAddress() + "," + value.getPhone());
}
@Override
public void onError(Throwable t) {
}
@Override
public void onCompleted() {
System.out.println("conCompleted");
}
});
requestStreamObserver.onNext(StreamRequest.newBuilder().setMessage("美美哒").build());
requestStreamObserver.onCompleted();
}
public static void main(String[] args) throws InterruptedException {
StudentClient client = new StudentClient("localhost",8080);
try{
client.getStreamUser();
}finally {
client.shutdown();
}
}
}
王八犊子《美美哒》,北京,123
conCompleted