encoding/json 包的使用

```go package main

import ( "fmt" "time" "encoding/json" )

type HttpResponse struct { Errorno int json:"errorno" Errmsg string json:"errmsg" Timestamp int64 json:"timestamp" ServerStatus int json:"serverstatus" Msg string json:"msg" Data map[string]interface{} json:"data" }

var httpresp = HttpResponse{ Errorno: 1, // Errmsg: "error", // 编码前不对该字段赋值 Timestamp: time.Now().Unix(), ServerStatus: 0, Msg: "msg", Data: map[string]interface{}{"id": 123}, }

jsonstr, err := json.Marshal(httpresp) if err != nil { fmt.Println("json encode err", err) }

fmt.Println("after encoding: ", string(jsonstr)) var afterjson HttpResponse err = json.Unmarshal(jsonstr, &afterjson) fmt.Printf("%+v", afterjson)

output:

after encoding:  {"errorno":1,"errmsg":"","timestamp":1466247295,"serverstatus":0,"msg":"msg","data":{"id":123}}
{Errorno:1 Errmsg: Timestamp:1466247295 ServerStatus:0 Msg:msg Data:map[id:123]}

说明：

1. json解码时会自动对编码字节流进行结构体里的字段进行匹配，如果匹配上了，则自动赋值给结构体变量，否则，直接舍弃。