第十章 json操作

第十章 json操作

一、Marshal 序列化

package main

import (
	"encoding/json"
	"fmt"
)
type Animal struct {
	Name  string `json:"name"`
	Order string `json:"order"`
}
func main() {
	var animals []Animal
	animals = append(animals, Animal{Name: "Platypus", Order: "Monotremata"})
	animals = append(animals, Animal{Name: "Quoll", Order: "Dasyuromorphia"})

	jsonStr, err := json.Marshal(animals)  // 也就是将可以转化成json的数据，进行json转换
	if err != nil {
		fmt.Println("error:", err)
	}

	fmt.Println(string(jsonStr))  // [{"name":"Platypus","order":"Monotremata"},{"name":"Quoll","order":"Dasyuromorphia"}]
}

不写tag也可以，使用tag起一个别名也好⛱️。

二、Unmarshal 反序列化

1 已知数据解析

package main

import (
    "encoding/json"
    "fmt"
)
type Animal struct {
    Name  string
    Order string
}
func main() {
    var jsonBlob = []byte(`[
        {"Name": "Platypus", "Order": "Monotremata"},
        {"Name": "Quoll",    "Order": "Dasyuromorphia"}
    ]`)

    var animals []Animal
    err := json.Unmarshal(jsonBlob, &animals)
    if err != nil {
        fmt.Println("error:", err)
    }
    fmt.Printf("%+v", animals)
}

2 未知数据解析

var f interface{}
b := []byte(`{"Name":"Wednesday","Age":6,"Parents":["Gomez","Morticia"]}`)

json.Unmarshal(b, &f)

for k, v := range f.(map[string]interface{}) {
    switch vv := v.(type) {
    case string:
        fmt.Println(k, "is string", vv)
    case int:
        fmt.Println(k, "is int ", vv)
    case float64:
        fmt.Println(k, "is float64 ", vv)
    case []interface{}:
        fmt.Println(k, "is array:")
        for i, j := range vv {
            fmt.Println(i, j)
        }
    }
}

3 json测试

package main

import (
	"encoding/json"
	"fmt"
)

type Base struct {
	Name  string   `json:"name"`
	Age   int      `json:"age"`
	Hobby []string `json:"hobby"`
}

type Person struct {
	BaseInfo Base
	ID       string
}

func main() {
	person := Person{BaseInfo: Base{"yangyi", 18, []string{"sing", "song"}}, ID: "123456789"}
	// 1 转化成json字符串
	jsonStr, err := json.Marshal(person)
	if err != nil {
		fmt.Println("json转换成功...")
	}
	fmt.Println(string(jsonStr))  // {"BaseInfo":{"Name":"yangyi","Age":18,"Hobby":["sing","song"]},"ID":"123456789"}

	// 2 json字符串反解析
	var person1 Person
	err = json.Unmarshal(jsonStr, &person1)
	if err != nil {
		fmt.Println("json字符串解析失败...")
	}
	fmt.Printf("%T\n", person1)  // main.Person
	fmt.Println(person1.BaseInfo.Hobby)  // [sing song]
}