golang "encoding/json"包实现了json对象的编解码
一、编码
func Marshal(v interface{}) ([]byte, error)Marshal函数使用下面的基于类型的默认编码格式：
布尔类型编码为json布尔类型。
浮点数、整数和Number类型的值编码为json数字类型。
字符串编码为json字符串。角括号"<"和">"会转义为"\u003c"和"\u003e"以避免某些浏览器吧json输出错误理解为HTML。基于同样的原因，"&"转义为"\u0026"。
数组和切片类型的值编码为json数组，但[]byte编码为base64编码字符串，nil切片编码为null。
结构体的值编码为json对象。每一个导出字段变成该对象的一个成员
Example:
1 package main 2 ?3 import( 4 ????"fmt" 5 ????"encoding/json" 6 ) 7 func main() { 8 ????type User struct{ 9 ????????Name string10 ????????Age int11 ????}12 ????user := User{13 ????????Name:"tom",14 ????????Age:3,15 ????}16 ????b, err := json.Marshal(user)17 ????if err != nil {18 ????????fmt.Println("json Marshal fail:", err)19 ????}20 ????fmt.Println(string(b))21 }Output:
{"Name":"tom","Age":3}1 不可导出字段，不会被编码
Example:
type User struct{ ???????Name string ???????age int ???} ???user := User{ ???????Name:"tom", ???????age:3, ???} ???b, _ := json.Marshal(user) ???fmt.Println(string(b))Output:
{"Name":"tom"}2 可通过结构体标签，改变编码的json对象
Example:
type User struct{ ???????Name string `json:"name"` ???????Age int ????`json:"ageeeeeeeeeeeeeeeeee"` ???} ???user := User{ ???????Name:"tom", ???????Age:3, ???} ???b, _ := json.Marshal(user) ???fmt.Println(string(b))Output:
{"name":"tom","ageeeeeeeeeeeeeeeeee":3}3 复杂结构体编码：
指针编码为它指向的值
切片编码为数组
结构体的值编码为json对象
Example:
???// 复杂结构体编码 ???//基本类型指针，结构体指针,切片，切片指针， ???type Contact struct { ???????Addr string ???????Phone string ???} ???type User struct { ???????Name string ???????Age *int ???????C1 *Contact ???????C2 []Contact ???????C3 []*Contact ???} ???age := 20 ???c1 := Contact{"北京","12345"} ???cArr := [...]Contact{Contact{"北京","11111"},Contact{"深圳","22222"},Contact{"上海","33333"}} ???c2 := cArr[:2] ???c3 := make([]*Contact,0) ???c3 = append(c3, &cArr[0]) ???c3 = append(c3, &cArr[1]) ???user := User{ ???????Name: ???"Tom", ???????Age: ????&age, ???????C1: ?????&c1, ???????C2: ?????c2, ???????C3: ?????c3, ???} ???fmt.Printf("struct: %v\n", user) ???b, _ := json.Marshal(user) ???fmt.Println("json: ", string(b))Output:
struct: {Tom 0xc04204a1c8 0xc042044580 [{北京 11111} {深圳 22222}] [0xc042086000 0xc042086020]}json: {"Name":"Tom","Age":20,"C1":{"Addr":"北京","Phone":"12345"},"C2":[{"Addr":"北京","Phone":"11111"},{"Addr":"深圳","Phone":"22222"}],"C3":[{"Addr":"北京","Phone":"11111"},{"Addr":"深圳","Phone":"22222"}]}二、解码
func Unmarshal(data []byte, v interface{}) errorExample
//json解码 测试 ???type Contact struct { ???????Addr string ???????Phone string ???} ???type User struct { ???????Name string ???????Age *int ???????C1 *Contact ???????C2 []Contact ???????C3 []*Contact ???} ???user := User{} ???j := `{ ???????????????"Name": "Tom", ???????????????"Age": 20, ???????????????"C1": { ???????????????????"Addr": "北京", ???????????????????"Phone": "12345" ???????????????}, ???????????????"C2": [{ ???????????????????"Addr": "北京", ???????????????????"Phone": "11111" ???????????????}, { ???????????????????"Addr": "深圳", ???????????????????"Phone": "22222" ???????????????}], ???????????????"C3": [{ ???????????????????"Addr": "北京", ???????????????????"Phone": "11111" ???????????????}, { ???????????????????"Addr": "深圳", ???????????????????"Phone": "22222" ???????????????}] ???????????}` ???err := json.Unmarshal([]byte(j), &user) ???if err != nil { ???????fmt.Println("json Unmarshal fail!") ???} ???fmt.Printf("%v\n", user) ???fmt.Println(*user.Age) ???fmt.Println(*user.C1) ???fmt.Println(*user.C3[0])Output
{Tom 0xc04204a3a8 0xc0420447a0 [{北京 11111} {深圳 22222}] [0xc042044860 0xc042044880]}20{北京 12345}{北京 11111}参考: Go语言标准库文档中文版
golang json 编码解码
原文地址：https://www.cnblogs.com/fhb2011/p/8975184.html