1、结构体 -> json串

package main

import (
    "encoding/json"
    "fmt"
    // "log"
    "os"
)

type Address struct {
    Type    string
    City    string
    Country string
}

type VCard struct {
    FirstName string
    LastName  string
    Addr []*Address
    Remark    string
}

func main() {
    // 将结构体转换成json str
    addr1 := &Address{"home", "gz", "cn"}
    addr2 := &Address{"comp", "hz", "cn"}
    vc := VCard{"Li", "JingLe", []*Address{addr1, addr2}, "remark1"}
    jsonStr, _ := json.Marshal(vc)
    fmt.Printf("JSON format: %s\n", jsonStr)

    // 生成Writer，可以写入文件
    file, _ := os.OpenFile("/Users/lijingle/Downloads/vcard.json", os.O_CREATE|os.O_WRONLY, 0666)
    defer file.Close()
    enc := json.NewEncoder(file)
    enc.Encode(vc)
    fmt.Printf("JSON from: %v\n", vc)
}

2、 json -> object

package main

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

type Address struct {
    Type    string
    City    string
    Country string
}

type VCard struct {
    FirstName string
    LastName  string
    Addr []*Address
    Remark    string
}

func main() {
    jsonObj := []byte(`{"FirstName":"Li","LastName":"JingLe","a":"1","Addr":[{"Type":"home","City":"gz","Country":"cn"},{"Type":"comp","City":"hz","Country":"cn"}],"Remark":"remark1"}`)

    // f 指向的值是一个 map，key 是一个字符串，value 是自身存储作为空接口类型的值：
    // 这种方式灵活但很麻烦
    var f interface{}
    json.Unmarshal(jsonObj, &f)
    m := f.(map[string]interface{})
    for k, v := range m {
        switch vv := v.(type) {
        case string:
            fmt.Println(k, "is string value = ", vv)
        case int:
            fmt.Println(k, "is int value = ", vv)
    
        case []interface{}:
            fmt.Println(k, "is an array:")
            for i, u := range vv {
                fmt.Println(i, u)
            }
        default:
            fmt.Println(k, "is of a type I don’t know how to handle")
        }
    }

    // 解析到指定构建体. json多了少了也无所谓,试了下能够正常解析
    var card VCard;
    json.Unmarshal(jsonObj, &card)
    fmt.Printf("%s\n", card.FirstName)
}