void sayHello() { std::cout << "Hello, world!" << std::endl;}
时间: 2024-05-25 09:18:57 浏览: 6
As an AI language model, I am not capable of actually executing code. However, I can understand what this code is doing and provide a description.
This code defines a function called "sayHello" which prints the message "Hello, world!" to the console using the "cout" function from the "iostream" library. The "endl" at the end of the output statement is used to add a new line after the message is printed.
相关问题
grpc::ServerBuilder 的使用列子
以下是使用 gRPC 的 C++ API 中的 `grpc::ServerBuilder` 构建 gRPC 服务器的一个简单示例:
```cpp
#include <iostream>
#include <memory>
#include <string>
#include <grpcpp/grpcpp.h>
#include "greeter.grpc.pb.h"
using grpc::Server;
using grpc::ServerBuilder;
using grpc::ServerContext;
using grpc::Status;
using helloworld::Greeter;
using helloworld::HelloReply;
using helloworld::HelloRequest;
// 实现 Greeter 服务
class GreeterServiceImpl final : public Greeter::Service {
Status SayHello(ServerContext* context, const HelloRequest* request,
HelloReply* reply) override {
std::string prefix("Hello ");
reply->set_message(prefix + request->name());
return Status::OK;
}
};
void RunServer() {
std::string server_address("0.0.0.0:50051");
GreeterServiceImpl service;
// 创建 ServerBuilder 对象并指定服务器地址
ServerBuilder builder;
builder.AddListeningPort(server_address, grpc::InsecureServerCredentials());
// 将 Greeter 服务添加到 gRPC 服务器中
builder.RegisterService(&service);
// 构建服务器并启动
std::unique_ptr<Server> server(builder.BuildAndStart());
std::cout << "Server listening on " << server_address << std::endl;
// 等待服务器关闭
server->Wait();
}
int main(int argc, char** argv) {
RunServer();
return 0;
}
```
在上面的示例中,我们首先实现了 `Greeter::Service`,并在其中实现了 `SayHello` 方法。然后,我们创建了一个 `GreeterServiceImpl` 对象,并将其注册到 `ServerBuilder` 中,使用 `AddListeningPort` 方法指定服务器地址和安全凭证,最后使用 `BuildAndStart` 方法构建 gRPC 服务器并启动。
写一个使用JSON作为序列化协议的gRPC通信的客户端和服务端
下面是一个使用JSON作为序列化协议的gRPC通信的客户端和服务端的示例,其中定义了一个名为`HelloWorld`的简单服务,客户端发送一个名为`name`的字符串,服务端返回一个包含`Hello, name!`的字符串:
#### 服务端
```cpp
#include <iostream>
#include <memory>
#include <string>
#include <grpcpp/grpcpp.h>
#include <grpcpp/server.h>
#include <grpcpp/server_builder.h>
#include <grpcpp/server_context.h>
#include "helloworld.grpc.pb.h"
using grpc::Server;
using grpc::ServerBuilder;
using grpc::ServerContext;
using grpc::Status;
using helloworld::HelloRequest;
using helloworld::HelloReply;
using helloworld::Greeter;
class GreeterServiceImpl final : public Greeter::Service {
Status SayHello(ServerContext* context, const HelloRequest* request,
HelloReply* reply) override {
std::string prefix("Hello, ");
reply->set_message(prefix + request->name());
return Status::OK;
}
};
void RunServer() {
std::string server_address("0.0.0.0:50051");
GreeterServiceImpl service;
grpc::EnableDefaultHealthCheckService(true);
grpc::reflection::InitProtoReflectionServerBuilderPlugin();
ServerBuilder builder;
builder.AddListeningPort(server_address, grpc::InsecureServerCredentials());
builder.RegisterService(&service);
std::unique_ptr<Server> server(builder.BuildAndStart());
std::cout << "Server listening on " << server_address << std::endl;
server->Wait();
}
int main(int argc, char** argv) {
RunServer();
return 0;
}
```
#### 客户端
```cpp
#include <iostream>
#include <memory>
#include <string>
#include <grpcpp/grpcpp.h>
#include <grpcpp/ext/proto_server_reflection_plugin.h>
#include <grpcpp/health_check_service_interface.h>
#include "helloworld.grpc.pb.h"
using grpc::Channel;
using grpc::ClientContext;
using grpc::Status;
using helloworld::HelloRequest;
using helloworld::HelloReply;
using helloworld::Greeter;
class GreeterClient {
public:
GreeterClient(std::shared_ptr<Channel> channel)
: stub_(Greeter::NewStub(channel)) {}
std::string SayHello(const std::string& name) {
HelloRequest request;
request.set_name(name);
HelloReply reply;
ClientContext context;
std::string serializedRequest, serializedReply;
grpc::SerializationTraits<HelloRequest>::serialize(request, &serializedRequest);
Status status = stub_->CallRPC("SayHello", serializedRequest, &serializedReply);
if (status.ok()) {
grpc::SerializationTraits<HelloReply>::deserialize(serializedReply, &reply);
return reply.message();
} else {
std::cout << "RPC failed: " << status.error_message() << std::endl;
return "";
}
}
private:
std::unique_ptr<Greeter::Stub> stub_;
};
int main(int argc, char** argv) {
std::string name("World");
GreeterClient greeter(grpc::CreateChannel("localhost:50051", grpc::InsecureChannelCredentials()));
std::string reply = greeter.SayHello(name);
std::cout << "Received: " << reply << std::endl;
return 0;
}
```
在这个例子中,我们使用了`grpc::SerializationTraits`类将请求和响应对象序列化为JSON字符串。`GreeterClient`类实现了客户端的逻辑,`SayHello`函数发送一个`HelloRequest`对象到服务端,并返回一个包含`Hello, name!`的字符串。在`main`函数中,我们使用`CreateChannel`函数创建一个与服务端通信的通道,并使用`GreeterClient`类进行通信。