grpc使用客户端技巧
grpc 使用技巧，最近在做的项目是服务端是go语言提供服务使用的是grpc框架。
java在实现客户端的时候，参数的生成大部分采用创建者模式。java在接受go服务端
返回数据的时候，更多的是通过parseFrom形式来创建。
go 服务端 java 客户端 proto 文件要有些差异，见文章 https://learnku.com/articles/36922?order_by=created_at&
demo样例：
import com.google.protobuf.ByteString;
import com.google.protobuf.Descriptors;
import com.google.protobuf.InvalidProtocolBufferException;
import io.grpc.ManagedChannel;
import io.grpc.ManagedChannelBuilder;
import io.grpc.StatusRuntimeException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import pino.RequestInstance2;
import pino.grpc.routeguide.*;
import pino.pino_resp_pb;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;
/**
* Created on 2017/5/4.
*/
public class PinoClient {
public static final RequestInstance2.FeatureGroup.Builder BUILDER_FEATURE = RequestInstance2.RequestInstance.newBuilder().getCommonFeature().toBuilder();
protected static final Logger logger = LoggerFactory.getLogger("file_logger");
private final ManagedChannel channel;
private final RouteGuideGrpc.RouteGuideBlockingStub blockingStub;
/** Construct client connecting to HelloWorld server at {@code host:port}. */
public PinoClient(String host, int port) {
this(ManagedChannelBuilder.forAddress(host, port)
// Channels are secure by default (via SSL/TLS). For the example we disable TLS to avoid
// needing certificates.
.usePlaintext(true));
}
/** Construct client for accessing RouteGuide server using the existing channel. */
PinoClient(ManagedChannelBuilder<?> channelBuilder) {
channel = channelBuilder.build();
blockingStub = RouteGuideGrpc.newBlockingStub(channel);
}
public void shutdown() throws InterruptedException {
channel.shutdown().awaitTermination(5, TimeUnit.SECONDS);
}
/** call pino to server. */
public Double callPino(double[] arr) {
if(logger.isInfoEnabled())
logger.info("start pino...");
if(arr==null)
return 0d;
RequestInstance2.Feature feature1 = RequestInstance2.RequestInstance.newBuilder()
.getCommonFeature().toBuilder().addFeaturesBuilder(0).setName("1").setSValue(String.valueOf(arr[0])).build();
RequestInstance2.Feature feature2 = RequestInstance2.RequestInstance.newBuilder()
.getCommonFeature().toBuilder().addFeaturesBuilder(0).setName("2").setSValue(String.valueOf(arr[1])).build();
RequestInstance2.Feature feature3 = RequestInstance2.RequestInstance.newBuilder()
.getCommonFeature().toBuilder().addFeaturesBuilder(0).setName("3").setSValue(String.valueOf(arr[2])).build();
RequestInstance2.Feature feature4 = RequestInstance2.RequestInstance.newBuilder()
.getCommonFeature().toBuilder().addFeaturesBuilder(0).setName("4").setSValue(String.valueOf(arr[3])).build();
RequestInstance2.Feature feature5 = RequestInstance2.RequestInstance.newBuilder()
.getCommonFeature().toBuilder().addFeaturesBuilder(0).setName("5").setSValue(String.valueOf(arr[4])).build();
RequestInstance2.Feature feature6 = RequestInstance2.RequestInstance.newBuilder()
.getCommonFeature().toBuilder().addFeaturesBuilder(0).setName("6").setSValue(String.valueOf(arr[5])).build();
RequestInstance2.Feature feature7 = RequestInstance2.RequestInstance.newBuilder()
.getCommonFeature().toBuilder().addFeaturesBuilder(0).setName("7").setSValue(String.valueOf(arr[6])).build();
RequestInstance2.Feature feature8 = RequestInstance2.RequestInstance.newBuilder()
.getCommonFeature().toBuilder().addFeaturesBuilder(0).setName("8").setSValue(String.valueOf(arr[7])).build();
RequestInstance2.Feature feature9 = RequestInstance2.RequestInstance.newBuilder()
.getCommonFeature().toBuilder().addFeaturesBuilder(0).setName("9").setSValue(String.valueOf(arr[8])).build();
RequestInstance2.Feature feature10 = RequestInstance2.RequestInstance.newBuilder()
.getCommonFeature().toBuilder().addFeaturesBuilder(0).setName("10").setSValue(String.valueOf(arr[9])).build();
RequestInstance2.Feature feature11 = RequestInstance2.RequestInstance.newBuilder()
.getCommonFeature().toBuilder().addFeaturesBuilder(0).setName("11").setSValue(String.valueOf(arr[10])).build();
RequestInstance2.RequestInstance.Builder builder = RequestInstance2.RequestInstance.newBuilder()
.addInstanceFeature(0, RequestInstance2.RequestInstance.newBuilder()
.getCommonFeature().toBuilder()
.addFeatures(0,feature1)
.addFeatures(1,feature2)
.addFeatures(2,feature3)
.addFeatures(3,feature4)
.addFeatures(4,feature5)
.addFeatures(5,feature6)
.addFeatures(6,feature7)
.addFeatures(7,feature8)
.addFeatures(8,feature9)
.addFeatures(9,feature10)
.addFeatures(10,feature11)
);
RequestInstance2.RequestInstance instance = builder.build();
byte[] bytes = instance.toByteArray();
ByteString bs = ByteString.copyFrom(bytes);
InputHead inputHead = InputHead.getDefaultInstance().toBuilder().setVersion(20).setBodySize(bs.size()).addAppKeys(0).setAppKeys(0, 85001).build();
Request request = Request.getDefaultInstance().toBuilder().setHead(inputHead).setBody(bs).build();
Response response = null;
try {
response = blockingStub.getPredictorValue(request);
} catch (StatusRuntimeException e) {
logger.error("RPC failed: "+ e.getStatus());
return 0d;
}
double value = 0d;
if(response!=null){
ByteString tempBytes = response.getBody();
try {
pino_resp_pb.Resp resp = pino_resp_pb.Resp.parseFrom(tempBytes);
if(resp.getOutputCount()>0){
pino_resp_pb.Output output = resp.getOutput(0);
pino_resp_pb.Matrix matrix = output.getMatrix();
if(matrix!=null&&matrix.getDoubleValCount()>0)
value = matrix.getDoubleVal(0);
}
System.out.println(value);
} catch (InvalidProtocolBufferException e) {
logger.error(e.getMessage(),e);
}
}
if(logger.isInfoEnabled())
logger.info("end pino.");
return value;
}
/**
* Greet server. If provided, the first element of {@code args} is the name to use in the
* greeting.
*/
public static void main(String[] args) throws Exception {
PinoClient client = new PinoClient("10.187.81.155", 80);
try {
/* Access a service running on the local machine on port 50051 */
String user = "world";
if (args.length > 0) {
user = args[0]; /* Use the arg as the name to greet if provided */
}
double[] features = {52.9186,4.2,0.0,0,0.03168337,8.771171,54.85312,0,0,0,0};
double[] features2 = {52.9186,4.2,0.0,0,0.03168337,8.771171,54.85312,0,0.03168337,8.771171,54.85312};
for(int i=0;i<10;i++){
client.callPino(features);
client.callPino(features2);
}
} finally {
client.shutdown();
}
}
}
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