golang结构体和json相互转换

1.结构体与json序列化

• golang需要给app或者小程序添加api接口就需要涉及到结构体和json序列间的转换
  json序列化就是将结构体数据转化成json格式的字符串，json的反序列化是将json数据转化成结构体对象。

1.1 结构体转换成json

package main

import (
	"encoding/json"
	"fmt"
)

type Student struct {
	ID int
	Name string
	Sex string
}

func main() {
	var s1 = Student{
		ID: 1,
		Name: "zhangsan",
		Sex: "man",
	}
	fmt.Printf("%#v \n",s1)     //main.Student{ID:1, Name:"zhangsan", Sex:"man"}
	jsonByte,_ := json.Marshal(s1)
	jsonStr := string(jsonByte)
	fmt.Printf("%v",jsonStr)   //{"ID":1,"Name":"zhangsan","Sex":"man"}
}

1.2 json转换成结构体

package main

import (
	"encoding/json"
	"fmt"
)

type Student struct {
	ID int
	Name string    //如果是小写，是私有字段，不能被json包访问
	Sex string
}

func main() {
	//2.json转结构体
	var str = `{"ID":12,"Name":"zhangsan","Sex":"man"}` //``进行转义
	var s1 Student
	err := json.Unmarshal([]byte(str),&s1)
	if err != nil {
		fmt.Println(err)
	}
	fmt.Printf("%#v \n",s1) //main.Student{ID:12, Name:"zhangsan", Sex:"man"}
}

2. 嵌套结构体和json的相互转换

2.1 嵌套结构体–>json

package main

import (
	"encoding/json"
	"fmt"
)

type Stu struct {
	ID int
	Name string
	Sex string
}

type Class struct {
	Tiele string
	Stud  []Stu   //结构体嵌套Stu结构体
}
func main() {
	c :=Class{
		Tiele: "001班",
		Stud: make([]Stu,0),
	}
	for i:=1;i<=3;i++ {
		s := Stu{
			ID: i,
			Name: fmt.Sprintf("stu_%v",i),
			Sex: "man",
		}
		c.Stud =append(c.Stud,s)
	}
	//fmt.Println(c)
	strByte,err := json.Marshal(c)
	if err != nil {
		fmt.Println(err)
	}else {
		strc := string(strByte)
		fmt.Printf("%v",strc) //{"Tiele":"001班","Stud":[{"ID":1,"Name":"stu_1","Sex":"man"},{"ID":2,"Name":"stu_2","Sex":"man"},{"ID":3,"Name":"stu_3","Sex":"man"}]}
	}
}

2.2 复杂json转结构体

package main

import (
	"encoding/json"
	"fmt"
)

type Stu struct {
	ID int
	Name string
	Sex string
}

type Class struct {
	Tiele string
	Stud  []Stu
}
func main() {
	var str = `{"Tiele":"001班","Stud":[{"ID":1,"Name":"stu_1","Sex":"man"},{"ID":2,"Name":"stu_2","Sex":"man"},{"ID":3,"Name":"stu_3","Sex":"man"}]}`
	var c = &Class{}
	err := json.Unmarshal([]byte(str),c)
	if err != nil {
		fmt.Println(err)
	}else {
		fmt.Printf("%#v",c)//&main.Class{Tiele:"001班", Stud:[]main.Stu{main.Stu{ID:1, Name:"stu_1", Sex:"man"}, main.Stu{ID:2, Name:"stu_2", Sex:"man"}, main.Stu{ID:3, Name:"stu_3", Sex:"man"}}}
	}
}