Go RPC 入门指南：RPC 的使用边界在哪里？如何实现跨语言调用？

package main
import (  "errors"  "fmt"  "log"  "net"  "net/http"  "net/rpc"  "os")
type Arith struct {
}
//请求结构体type ArithRequest struct {  A int  B int}
//响应结构体type ArithResponse struct {  Pro int //乘积  Quo int //商  Rem int //余数}
//乘积方法func (this *Arith) Multiply(req ArithRequest,res *ArithResponse) error{  res.Pro = req.A * req.B  return nil}
//除法运算方法func (this *Arith) Divide(req ArithRequest,res *ArithResponse) error{  if req.B ==0 {    return  errors.New("divide by zero")  }  res.Quo = req.A / req.B  res.Rem = req.A % req.B  return nil}
func main()  {  //注册rpc服务  rpc.Register(new(Arith))  //采用http协议作为rpc载体  rpc.HandleHTTP()
  lis,err := net.Listen("tcp","127.0.0.1:8095")  if err!=nil {    log.Fatalln("fatal error:",err)  }
  fmt.Fprintf(os.Stdout,"%s","start connection\n")
  //常规启动http服务  http.Serve(lis,nil)}

package main
import (  "fmt"  "log"  "net/rpc")
//算数运算请求结构体type ArithRequest struct {  A int  B int}
//响应结构体type ArithResponse struct {  Pro int //乘  Quo int //商  Rem int //余数}
func main()  {  conn,err := rpc.DialHTTP("tcp","127.0.0.1:8095")  if err!=nil {    log.Fatalln("dialing error:",err)  }
  req := ArithRequest{10,20}  var res  ArithResponse
  err = conn.Call("Arith.Multiply",req,&res) //乘法运算  if err!=nil {    log.Fatalln("arith error:",err)  }  fmt.Printf("%d * %d = %d\n",req.A,req.B,res.Pro)
  //除法运算  err = conn.Call("Arith.Divide",req,&res)  if err!=nil {    log.Fatalln("arith error:",err)  }  fmt.Printf("%d / %d = %d 余数是:%d",req.A,req.B,res.Quo,res.Rem)}

//服务端consolestart connection
//客户端console10 * 20 = 20010 / 20 = 0 余数是:10

package main
import (  "errors"  "fmt"  "log"  "net"  "net/rpc"  "net/rpc/jsonrpc"  "os")
type Arith struct {
}
//请求结构体type ArithRequest struct {  A int  B int}
//响应结构体type ArithResponse struct {  Pro int //乘积  Quo int //商  Rem int //余数}
//乘积方法func (this *Arith) Multiply(req ArithRequest,res *ArithResponse) error{  res.Pro = req.A * req.B  return nil}
//除法运算方法func (this *Arith) Divide(req ArithRequest,res *ArithResponse) error{  if req.B ==0 {    return  errors.New("divide by zero")  }  res.Quo = req.A / req.B  res.Rem = req.A % req.B  return nil}
func main()  {  //注册rpc服务  rpc.Register(new(Arith))  //采用http协议作为rpc载体  rpc.HandleHTTP()
  lis,err := net.Listen("tcp","127.0.0.1:8096")  if err!=nil {    log.Fatalln("fatal error:",err)  }
  fmt.Fprintf(os.Stdout,"%s","start connection\n")
  //接收客户端请求 并发处理 jsonrpc  for {    conn,err :=lis.Accept() //接收客户端连接请求    if err!=nil {      continue    }
    //并发处理客户端请求    go func(conn net.Conn) {      fmt.Fprintf(os.Stdout,"%s","new client in coming\n")      jsonrpc.ServeConn(conn)    }(conn)  }
  //常规启动http服务  //http.Serve(lis,nil)}

package main
import (  "fmt"  "log"  "net/rpc/jsonrpc")
//算数运算请求结构体type ArithRequest struct {  A int  B int}
//响应结构体type ArithResponse struct {  Pro int //乘  Quo int //商  Rem int //余数}
func main()  {  // 只有这里不一样  conn,err := jsonrpc.Dial("tcp","127.0.0.1:8096")  if err!=nil {    log.Fatalln("dialing error:",err)  }
  req := ArithRequest{9,2}  var res  ArithResponse
  err = conn.Call("Arith.Multiply",req,&res) //乘法运算  if err!=nil {    log.Fatalln("arith error:",err)  }  fmt.Printf("%d * %d = %d\n",req.A,req.B,res.Pro)
  //除法运算  err = conn.Call("Arith.Divide",req,&res)  if err!=nil {    log.Fatalln("arith error:",err)  }  fmt.Printf("%d / %d = %d 余数是:%d",req.A,req.B,res.Quo,res.Rem)}

//服务端consolestart connection
//客户端console9 * 2 = 189 / 2 = 4 余数是:1
//服务端consolenew client in coming

<?php

class JsonRPC{
    private $conn;
    function __construct($host, $port)    {        $this->conn = fsockopen($host, $port, $errno, $errstr, 3);        if (!$this->conn) {            return false;        }    }
    public function Call($method, $params)    {        if (!$this->conn) {            return false;        }        $err = fwrite($this->conn, json_encode(array(                'method' => $method,                'params' => array($params),                'id' => 0,            )) . "\n");        if ($err === false) {            return false;        }        stream_set_timeout($this->conn, 0, 3000);        $line = fgets($this->conn);        if ($line === false) {            return NULL;        }        return json_decode($line, true);    }}
$client = new JsonRPC("127.0.0.1", 8096);$args = array('A' => 9, 'B' => 2);$r = $client->Call("Arith.Multiply", $args);printf("%d * %d = %d\n", $args['A'], $args['B'], $r['result']['Pro']);$r = $client->Call("Arith.Divide", array('A' => 9, 'B' => 2));printf("%d / %d, Quo is %d, Rem is %d\n", $args['A'], $args['B'], $r['result']['Quo'], $r['result']['Rem']);

//本地启动PHP服务：http://127.0.0.1/jsonrpc_client.php，运行结果如下：9 * 2 = 18 9 / 2, Quo is 4, Rem is 1