Go JSON-RPC over HTTP

http_jsonrpc.go

package main

import (
	"io"
	"log"
	"net"
	"net/http"
	"net/rpc"
	"net/rpc/jsonrpc"
)

type RootNamespace struct{}
type RootNamespaceArgs struct {
	Name string
}

type HttpConn struct {
	in  io.Reader
	out io.Writer
}

func (c *HttpConn) Read(p []byte) (n int, err error)  { return c.in.Read(p) }
func (c *HttpConn) Write(d []byte) (n int, err error) { return c.out.Write(d) }
func (c *HttpConn) Close() error                      { return nil }

func (ns *RootNamespace) SayHello(args *RootNamespaceArgs, reply *string) error {
	name := args.Name
	*reply = string("Hello " + name)
	return nil
}

func main() {
	server := rpc.NewServer()
	server.RegisterName("Root", &RootNamespace{})
	server.HandleHTTP(rpc.DefaultRPCPath, rpc.DefaultDebugPath)

	listener, e := net.Listen("tcp", ":3000")
	if e != nil {
		log.Fatal("Listen error:", e)
	}

	defer listener.Close()
	http.Serve(listener, http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {

		if r.URL.Path == "/rpc" {
			serverCodec := jsonrpc.NewServerCodec(&HttpConn{in: r.Body, out: w})
			w.Header().Set("Content-type", "application/json")
			w.WriteHeader(200)
			err := server.ServeRequest(serverCodec)
			if err != nil {
				log.Printf("Error while serving JSON request: %v", err)
				http.Error(w, "Error while serving JSON request, details have been logged.", 500)
				return
			}
		}
	}))
}