I'm new to Golang and am using the "Server" code here as a starting point: http://www.golang-book.com/13/index.htm#section7
I've attempted to use JSON instead of Gob decoding (since I am required to write the client in C#), and I'm sending the JSON TCP data client data in a separate script from the code below.
I'm stuck on the part where I'm actually receiving the JSON TCP data and storing it in a variable for it to be decoded. It looks like I can decode it with json.Unmarshal
, but I can't find any examples where json.Unmarshal
is being used to decode TCP data. I can only find examples where json.Unmarshal
is being used to decode JSON strings.
My code is below:
package main
import (
"encoding/json"
"fmt"
"net"
)
type coordinate struct {
X float64 `json:"x"`
Y float64 `json:"y"`
Z float64 `json:"z"`
}
func server() {
// listen on a port
ln, err := net.Listen("tcp", ":9999")
if err != nil {
fmt.Println(err)
return
}
for {
// accept a connection
c, err := ln.Accept()
if err != nil {
fmt.Println(err)
continue
}
// handle the connection
go handleServerConnection(c)
}
}
func handleServerConnection(c net.Conn) {
// receive the message
var msg coordinate
Stuck on the line below. What could I set the rawJSON variable equal to?
err := json.Unmarshal([]byte(rawJSON), &msg)
if err != nil {
fmt.Println(err)
} else {
fmt.Println("Received", msg)
}
c.Close()
}
func main() {
go server()
//let the server goroutine run forever
var input string
fmt.Scanln(&input)
}
json is read with the ioutil. ReadFile() function, which returns a byte slice that is decoded into the struct instance using the json. Unmarshal() function. At last, the struct instance member values are printed using for loop to demonstrate that the JSON file was decoded.
JSON (JavaScript Object Notation) is a simple data interchange format. Syntactically it resembles the objects and lists of JavaScript. It is most commonly used for communication between web back-ends and JavaScript programs running in the browser, but it is used in many other places, too.
You can patch a json.Decoder
directly to the connection:
func handleServerConnection(c net.Conn) {
// we create a decoder that reads directly from the socket
d := json.NewDecoder(c)
var msg coordinate
err := d.Decode(&msg)
fmt.Println(msg, err)
c.Close()
}
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