1. json字符串解析： json.Unmarshal(b, &f)

• json字符串解析到结构体中：

package main

import (
    "encoding/json"
    "fmt"
)

type Server struct {
    ServerName string
    ServerIP   string
}

type Serverslice struct {
    Servers []Server
}

func main() {
    var s Serverslice
    str := `{"servers":[{"serverName":"Shanghai_VPN","serverIP":"127.0.0.1"},{"serverName":"Beijing_VPN","serverIP":"127.0.0.2"}]}`
    err := json.Unmarshal([]byte(str), &s)
    if err != nil {
        fmt.Println(err)
    } else {
        fmt.Printf("%T, %v \n", s, s)
        for _, item := range s.Servers {
            fmt.Println(item)
        }
    }
}

输出结果：

main.Serverslice, {[{Shanghai_VPN 127.0.0.1} {Beijing_VPN 127.0.0.2}]} 
{Shanghai_VPN 127.0.0.1}
{Beijing_VPN 127.0.0.2}

• json字符串直接解析到map中：

package main

import (
    "encoding/json"
    "fmt"
)

func main() {
    b := []byte(`{"Name":"Wednesday","Age":6,"Parents":["Gomez","Morticia"]}`)
    var f map[string]interface{}
    err := json.Unmarshal(b, &f)
    if err != nil {
        fmt.Println(err)
    }
    fmt.Printf("type: %T, value: %v\n", f["Age"], f["Age"])
    fmt.Printf("type: %T, value: %v\n", f["Parents"], f["Parents"])
}

输出：

type: float64, value: 6
type: []interface {}, value: [Gomez Morticia]

• 直接解析，不用结构体也不用map
  使用以下的json包：
  go get -u github.com/tidwall/gjson
  示例代码：

package main

import (
    "fmt"
    "github.com/tidwall/gjson"
)

func main() {
    str := `{"name": "shanhuhai", "sex": 1,"height": 175, "classmate": ["王小五","赵小六","白小七"]}`

    name := gjson.Get(str, "name")
    classmate := gjson.Get(str, "classmate")
    fmt.Println(name)

    if classmate.IsArray() {
        fmt.Println(classmate.Array()[0])
        fmt.Println(classmate.Array()[1])
        fmt.Println(classmate.Array()[2])
    }
}

输出：

shanhuhai
王小五
赵小六
白小七

2.生成Json：json.Marshal(s)

• 结构体转json

package main

import (
    "encoding/json"
    "fmt"
)

type Server struct {
    ServerName string
    ServerIP   string
}

type Serverslice struct {
    Servers []Server
}

func main() {
    var s Serverslice
    s.Servers = append(s.Servers, Server{ServerName: "Shanghai_VPN", ServerIP: "127.0.0.1"})
    s.Servers = append(s.Servers, Server{ServerName: "Beijing_VPN", ServerIP: "127.0.0.2"})
    b, err := json.Marshal(s)
    if err != nil {
        fmt.Println("json err:", err)
    }
    fmt.Println(string(b))
}

输出：

{"Servers":[{"ServerName":"Shanghai_VPN","ServerIP":"127.0.0.1"},{"ServerName":"Beijing_VPN","ServerIP":"127.0.0.2"}]}

• map直接转json

package main

import (
    "encoding/json"
    "fmt"
)

func main() {
    var m = map[string]interface{} {"age":20, "name":"lili", "gender":"女"}
    b, err := json.Marshal(m)
    if err != nil {
        fmt.Println("json err:", err)
    }
    fmt.Println(string(b))
}

输出：

{"age":20,"gender":"女","name":"lili"}