{
 "user": {
  "mspid": "admin",
  "email": "admin@domain.com"
 }, 
 "nodes": [
  {  
   "name": "node1",
   "location": "node1.domain.com:8080"
  }, 
  {  
   "name": "node2",
   "location": "node2.domain.com:8080"
  }  
 ]
}

import (
  "fmt"
  "io/ioutil"
  "encoding/json"
)

func HandleJson(jsonFile string, outFile string) error {
  // Read json buffer from jsonFile
  byteValue, err := ioutil.ReadFile(jsonFile)
  if err != nil {
    return err
  }

  // We have known the outer json object is a map, so we define result as map.
  // otherwise, result could be defined as slice if outer is an array
  var result map[string]interface{}
  err = json.Unmarshal(byteValue, &result)
  if err != nil {
    return err
  }

  // handle peers
  nodes:= result["nodes"].([]interface{})
  for _, node:= range node{
    m := node.(map[string]interface{})
    if name, exists := m["name"]; exists {
      if name == "node1" {
        m["location"] = "new-value1"
      } else if name == "node2" {
        m["location"] = "new-value2"
      }
    }
  }

  // Convert golang object back to byte
  byteValue, err = json.Marshal(result)
  if err != nil {
    return err
  }

  // Write back to file
  err = ioutil.WriteFile(outFile, byteValue, 0644)
  return err
}

var x interface{} = ...

switch x.(type) {
  case nil:
    fmt.Println("x is nil")
  case int: 
    fmt.Println("x is int")
  case bool :
    fmt.Println("x is bool")
  case string:
    fmt.Println("x is string")
  case []interface{}:
    fmt.Println("x is slice")
  case map[string]interface{}:
    fmt.Println("x is map")
  default:
    fmt.Println("type unknown")
  }  
}

package main

import "github.com/json-iterator/go"

type User struct {
  Name string
  Age int8
}

func main() {
  user := User{
      Name: "tanggu",
      Age: 18,
    }
    var jsoniter = jsoniter.ConfigCompatibleWithStandardLibrary
    // 序列化
    data, err := jsoniter.Marshal(&user)
    if err != nil {
      log.Fatal(err)
    }
    fmt.Println(string(data))

    // 反序列化
    var people User
    err = jsoniter.Unmarshal(data, &people)
    if err != nil {
      log.Fatal(err)
    }
    fmt.Println(people)
}