Golang结构体和Json相互转换 序列化 反序列化
# 一、关于 JSON 数据
JSON(JavaScript Object Notation) 是一种轻量级的数据交换格式。易于人阅读和编写。同时也易于机器解析和生成。RESTfull Api 接口中返回的数据都是 json 数据。
Json 的基本格式如下：
{
"a": "Hello",
"b": "World"
}
稍微复杂点的 JSON
{
"result": [
{
"_id": "59f6ef443ce1fb0fb02c7a43",
"title": "笔记本电脑",
"status": "1",
"pic": "public\\upload\\UObZahqPYzFvx_C9CQjU8KiX.png",
"url": "12"
},
{
"_id": "5a012efb93ec4d199c18d1b4",
"title": "第二个轮播图",
"status": "1",
"pic": "public\\upload\\f3OtH11ZaPX5AA4Ov95Q7DEM.png"
},
{
"_id": "5a012f2433574208841e0820",
"title": "第三个轮播图",
"status": "1",
"pic": "public\\upload\\s5ujmYBQVRcLuvBHvWFMJHzS.jpg"
},
{
"_id": "5a688a0ca6dcba0ff4861a3d",
"title": "教程",
"status": "1",
"pic": "public\\upload\\Zh8EP9HOasV28ynDSp8TaGwd.png"
}
]
}
# 二、结构体与 JSON 序列化
比如我们 Golang 要给 App 或者小程序提供 Api 接口数据，这个时候就需要涉及到结构体和Json 之间的相互转换
Golang JSON 序列化是指把结构体数据转化成 JSON 格式的字符串，Golang JSON 的反序列化是指把 JSON 数据转化成 Golang 中的结构体对象
Golang 中 的 序 列 化 和 反 序 列 化 主 要 通 过"encoding/json" 包 中 的 json.Marshal() 和 json.Unmarshal()方法实现
# 1、结构体对象转化成 Json 字符串
package main
import (
"encoding/json"
"fmt"
)
type Student struct {
ID int
Gender string
name string //私有属性不能被 json 包访问
Sno string
}
func main() {
var s1 = Student{
ID: 1, Gender: "男", name: "李四", Sno: "s0001"}
fmt.Printf("%#v\n", s1)
var s, _ = json.Marshal(s1)
jsonStr := string(s)
fmt.Println(jsonStr)
}
输出结果：
main.Student{ID:1, Gender:"男", name:"李四", Sno:"s0001"}
{"ID":1,"Gender":"男","Sno":"s0001"}
# 2、Json 字符串转换成结构体对象
package main
import (
"encoding/json"
"fmt"
)
type Student struct {
ID int
Gender string
Name string
Sno string
}
func main() {
// var jsonStr = "{\"ID\":1,\"Gender\":\"男\",\"Name\":\"李四\",\"Sno\":\"s0001\"}"
var jsonStr = `{"ID":1,"Gender":"男","Name":"李四","Sno":"s0001"}` //定义一个 Monster 实例
var student Student
err := json.Unmarshal([]byte(jsonStr), &student)
if err != nil {
fmt.Printf("unmarshal err=%v\n", err)
}
fmt.Printf("反序列化后 student=%#v student.Name=%v \n", student, student.Name)
}
输出结果：
反序列化后 student=main.Student{ID:1, Gender:"男", Name:"李四", Sno:"s0001"} student.Name=李四
# 三、结构体标签 Tag
Tag 是结构体的元信息，可以在运行的时候通过反射的机制读取出来。 Tag 在结构体字段的后方定义，由一对反引号包裹起来，具体的格式如下：
key1:"value1" key2:"value2" 结构体 tag 由一个或多个键值对组成。键与值使用冒号分隔，值用双引号括起来。同一个结构体字段可以设置多个键值对 tag，不同的键值对之间使用空格分隔。
注意事项： 为结构体编写 Tag 时，必须严格遵守键值对的规则。结构体标签的解析代码的容错能力很差，一旦格式写错，编译和运行时都不会提示任何错误，通过反射也无法正确取值。例如不要在 key 和 value 之间添加空格。
package main
import (
"encoding/json"
"fmt"
)
type Student struct {
ID int `json:"id"` //通过指定 tag 实现 json 序列化该字段时的 key
Gender string `json:"gender"`
Name string
Sno string
}
func main() {
var s1 = Student{
ID: 1, Gender: "男", Name: "李四", Sno: "s0001"}
fmt.Printf("%#v\n", s1)
var s, _ = json.Marshal(s1)
jsonStr := string(s)
fmt.Println(jsonStr)
}
输出结果：
main.Student{ID:1, Gender:"男", Name:"李四", Sno:"s0001"}
{"id":1,"gender":"男","Name":"李四","Sno":"s0001"}
package main
import (
"encoding/json"
"fmt"
)
type Student struct {
ID int `json:"id"` //通过指定 tag 实现 json 序列化该字段时的 key
Gender string `json:"gender"`
Name string
Sno string
}
func main() {
var s2 Student
var str = "{\"id\":1,\"gender\":\"男\",\"Name\":\"李四\",\"Sno\":\"s0001\"}"
err := json.Unmarshal([]byte(str), &s2)
if err != nil {
fmt.Println(err)
}
fmt.Printf("%#v", s2)
}
输出结果：
main.Student{ID:1, Gender:"男", Name:"李四", Sno:"s0001"}
# 四、嵌套结构体和 JSON 序列化反序列化
package main
import (
"encoding/json"
"fmt"
)
// Student 学生
type Student struct {
ID int
Gender string
Name string
}
// Class 班级
type Class struct {
Title string
Students []Student
}
func main() {
c := &Class{
Title: "001", Students: make([]Student, 0, 200)}
for i := 0; i < 10; i++ {
stu := Student{
Name: fmt.Sprintf("stu%02d", i), Gender: "男", ID: i}
c.Students = append(c.Students, stu)
}
//JSON 序列化：结构体-->JSON 格式的字符串
data, err := json.Marshal(c)
if err != nil {
fmt.Println("json marshal failed")
return
}
fmt.Printf("json:%s\n", data)
}
输出结果：
json:{"Title":"001","Students":[{"ID":0,"Gender":"男","Name":"stu00"},{"ID":1,"Gender":"男","Name":"stu01"},{"ID":2,"Gender":"男","Name":"stu02"},{"ID":3,"Gender":"男","Name":"stu03"},{"ID":4,"Gender":"男","Name":"stu04"},{"ID":5,"Gender":"男","Name":"stu05"},{"ID":6,"Gender":"男","Name":"stu06"},{"ID":7,"Gender":"男","Name":"stu07"},{"ID":8,"Gender":"男","Name":"stu08"},{"ID":9,"Gender":"男","Name":"stu09"}]}
package main
import (
"encoding/json"
"fmt"
)
// Student 学生
type Student struct {
ID int
Gender string
Name string
}
// Class 班级
type Class struct {
Title string
Students []Student
}
func main() {
str := `{
"Title": "001",
"Students": [
{ "ID": 0, "Gender": "男", "Name": "stu00" },
{ "ID": 1, "Gender": "男", "Name": "stu01" },
{ "ID": 2, "Gender": "男", "Name": "stu02" },
{ "ID": 3, "Gender": "男", "Name": "stu03" },
{ "ID": 4, "Gender": "男", "Name": "stu04" },
{ "ID": 5, "Gender": "男", "Name": "stu05" },
{ "ID": 6, "Gender": "男", "Name": "stu06" },
{ "ID": 7, "Gender": "男", "Name": "stu07" },
{ "ID": 8, "Gender": "男", "Name": "stu08" },
{ "ID": 9, "Gender": "男", "Name": "stu09" }
]
}`
c1 := &Class{}
err := json.Unmarshal([]byte(str), c1)
if err != nil {
fmt.Println("json unmarshal failed!")
return
}
fmt.Printf("%#v\n", c1)
}
输出结果：
&main.Class{Title:"001", Students:[]main.Student{main.Student{ID:0, Gender:"男", Name:"stu00"}, main.Student{ID:1, Gender:"男", Name:"stu01"}, main.Student{ID:2, Gender:"男", Name:"stu02"}, main.Student{ID:3, Gen:"男", Name:"stu03"}, main.Student{ID:4, Gender:"男", Name:"04"}, main.Student{ID:5, Gender:"男", Name:"stu05"}, main.Student{ID:6, Gender:"男", Name:"stu06"}, main.Student{ID:7, Gender:"男", Name:"stu07"}, main.nt{ID:8, Gender:"男", Name:"stu08"}, main.Student{ID:9, Gender:"男", Name:"stu09"}}}
# 五、关于 Map、切片的序列化反序列化
Map 和切片也可以进行序列化和反序列化，在讲完接口后再去给大家详细讲解
上次更新: 2025/03/22, 00:19:03