修复grpc 返回字段为该字段类型的默认值时，不传该字段问题

字段为该字段类型的默认值时，不传该字段问题"/>

修复grpc 返回字段为该字段类型的默认值时，不传该字段问题

在使用go 的grpc通信时，会有一个坑，当grpc 返回字段为该字段类型的默认值时，为了节省带宽，不会传输该字段，这对客户端来说，数据结构不严谨，解决办法

grpc :

import (pb "github/golang/protobuf/jsonpb"
)func marshalJsonp(pbMsg proto.Message) (msg []byte, err error) {m := pb.Marshaler{EmitDefaults: true, OrigName: true}var data bytes.Buffererr = m.Marshal(&data, pbMsg)return data.Bytes(), err
}

grpc-gateway

package mainimport ("flag""net/http""github/golang/glog""golang/x/net/context""github/grpc-ecosystem/grpc-gateway/runtime""google.golang/grpc"gw "path/to/your_service_package"
)var (echoEndpoint = flag.String("echo_endpoint", "localhost:9090", "endpoint of YourService")
)func run() error {ctx := context.Background()ctx, cancel := context.WithCancel(ctx)defer cancel()mux := runtime.NewServeMux(runtime.WithMarshalerOption(runtime.MIMEWildcard, &runtime.JSONPb{OrigName: true, EmitDefaults: true})opts := []grpc.DialOption{grpc.WithInsecure()}err := gw.RegisterYourServiceHandlerFromEndpoint(ctx, mux, *echoEndpoint, opts)if err != nil {return err}return http.ListenAndServe(":8080", mux)
}func main() {flag.Parse()defer glog.Flush()if err := run(); err != nil {glog.Fatal(err)}
}

起作用的就是下面这句配置：

 mux := runtime.NewServeMux(runtime.WithMarshalerOption(runtime.MIMEWildcard, &runtime.JSONPb{OrigName: true, EmitDefaults: true})