结构体转map[string]interface{}方式

结构体转map[string]interface{}的若干方法

1.JSON序列化方式

• 先用JSON序列化，再反序列化转成map：

  package main
  
  import (
  	"encoding/json"
  	"fmt"
  )
  type UserInfo struct {
  	Name string `json:"name"`
  	Age int `json:"age"`
  }
  
  
  func main (){
  	u1 := UserInfo{Name:"xujunkai", Age:20}
  	fmt.Printf("%T
  ", u1)// main.UserInfo
  	var mp map[string]interface{}
  	// byte_u1为byte类型切片
  	byte_u1, _ := json.Marshal(&u1)
  	fmt.Printf("%T
  ", byte_u1)
  	_ = json.Unmarshal(byte_u1, &mp)
  	fmt.Println(mp)// map[name:xujunkai age:20]
      
      for k,v := range(mp) {
  		fmt.Printf("key:%v  value:%v
  ", k, v)
  	}
      // key:name  value:xujunkai
  	// key:age  value:20
  }
  
  

2. 反射方法

• 通过反射遍历结构体字段方式生成map

  package main
  import (
  	"fmt"
  	"reflect"
  )
  type UserInfo struct {
  	Name string `json:"name"`
  	Age int `json:"age"`
  }
  
  func reflexToMap(in interface{}, tagName string) (map[string]interface{},error) {
  	out := make(map[string]interface{})
  	// 获取 in的值对象
  	v := reflect.ValueOf(in)
  	fmt.Println("v:", v)
  	fmt.Println("v的类型为:", v.Kind())// ptr  指针类型
  	// 判断当前值对象是否为指针类型
  	if v.Kind() == reflect.Ptr {
  		// 通过v.Elem获取值指向元素的值
  		fmt.Println(v.Elem())// {xujunkai 20}
  		v = v.Elem()
  	}
  	fmt.Println(v.Kind()) // struct
  	// 判断类型不为结构体报错
  	if v.Kind() != reflect.Struct {
  		return nil, fmt.Errorf("not struct")
  	}
  
  	t := v.Type()
  	fmt.Println(t)
  	// 遍历结构体字段，指定tagName值，为map中key,字段值为map中value
  	for i:= 0; i < v.NumField(); i++ {
  		fi := t.Field(i)
  		fmt.Println("fi:", fi)
  		if tagValue := fi.Tag.Get(tagName); tagValue != "" {
  			out[tagValue] = v.Field(i).Interface()
  		}
  	}
  	return out, nil
  }
  func main (){
  	u1 := UserInfo{Name:"xujunkai", Age:20}
  	m2, _ := reflexToMap(&u1,"json")
  	for k, v := range(m2) {
  		fmt.Printf("key:%v  value:%v
  ", k, v)
  	}
  }
  

3.第三方库

• 下载

  go get github.com/fatih/structs
  

• 示例：

  
  import (
  	"fmt"
  	"github.com/fatih/structs"
  )
  
  
  u1 := UserInfo{Name:"xujunkai", Age:20}
  m3 := structs.Map(&u1)
  fmt.Println(m3)
  

4.嵌套结构体转map[string]interface{}

• structs本身支持嵌套结构体转map[string]interface{},遇到嵌套结构体它会转换为map[string]interface{}嵌套map[string]interface{}的模式

  package main
  
  import (
  	"fmt"
  	"github.com/fatih/structs"
  )
  
  type UserInfo struct {
  	Name string `json:"name" structs:"name"`
  	Age int `json:"age" structs:"age"`
  	Profile `json:"profile" structs:"profile"`
  }
  type Profile struct {
  	Hobby string `json:"hobby" structs:"hobby"`
  }
  func main (){
  	u1 := UserInfo{Name:"xujunkai", Age: 18, Profile:Profile{Hobby:"swimming"}}
  	m3 := structs.Map(&u1)
  	fmt.Println(m3)
  	for k,v := range(m3) {
  		fmt.Printf("key:%s value:%v type:%T
  ",k,v,v)
  	}
  }