package main
import (
"encoding/json"
"fmt"
)
/**
* @author micro.cloud.fly
* @date 2022/2/10 5:24 下午
* @desc
*/
type Person struct {
Id int `json:"id,string"`
Age int `json:"age,string"`
}
func main() {
p := Person{
Id: 12,
Age: 14,
}
marshal, _ := json.Marshal(p)
fmt.Println(string(marshal))
s := `{"id":"20","age":"20"}`
_ = json.Unmarshal([]byte(s), &p)
fmt.Printf("%#v", p)
}
输出：
{"id":"12","age":"14"}
main.Person{Id:20, Age:20}
package main
import (
"bytes"
"encoding/json"
"fmt"
)
/**
* @author micro.cloud.fly
* @date 2022/2/10 5:24 下午
* @desc
*/
func main() {
m := make(map[string]interface{})
m["age"] = 1
marshal, _ := json.Marshal(m)
fmt.Println(string(marshal))
s:= `{"age":34}`
_= json.Unmarshal([]byte(s), &m)
fmt.Printf("%#v\n",m)
//⚠️⚠️注意此时的age是float64类型⚠️⚠️
fmt.Printf("%T\n",m["age"])
decoder := json.NewDecoder(bytes.NewBuffer([]byte(s)))
decoder.UseNumber()
_ = decoder.Decode(&m)
fmt.Printf("%#v\n",m)
//打印可以看出此时age是json.Number类型
fmt.Printf("%T\n",m["age"])
//⚠️⚠️此处进行断言后调用Int64()方法⚠️⚠️
i, _ := m["age"].(json.Number).Int64()
fmt.Printf("%#v\n",i)
fmt.Printf("%T\n",i)
}
输出：
{"age":1}
map[string]interface {}{"age":34}
float64
map[string]interface {}{"age":"34"}
json.Number
34
int64
问题原因
package main
import (
"encoding/json"
"fmt"
"time"
)
/**
* @author micro.cloud.fly
* @date 2022/2/10 5:24 下午
* @desc
*/
type Person struct {
Birthday time.Time `json:"birthday"`
}
func main() {
p := Person{Birthday: time.Now()}
marshal, _ := json.Marshal(p)
fmt.Println(string(marshal)) //输出： {"birthday":"2022-02-10T18:05:15.821518+08:00"}
s := `{"birthday":"2022-02-10 10:00:00"}`
err := json.Unmarshal([]byte(s), &p)
//可以看到，对我们习惯对格式化对时间字符串，不是很友好，直接报错了
fmt.Println(err, p) //输出：parsing time ""2022-02-10 10:00:00"" as ""2006-01-02T15:04:05Z07:00"": cannot parse " 10:00:00"" as "T" {0001-01-01 00:00:00 +0000 UTC}
}
输出：
{"birthday":"2022-02-10T18:06:41.992661+08:00"}
parsing time ""2022-02-10 10:00:00"" as ""2006-01-02T15:04:05Z07:00"": cannot parse " 10:00:00"" as "T" {0001-01-01 00:00:00 +0000 UTC}
解决方案：
package main
import (
"encoding/json"
"fmt"
"time"
)
/**
* @author micro.cloud.fly
* @date 2022/2/10 5:24 下午
* @desc
*/
var format = "2006-01-02 15:04:05"
type Student struct {
Id int `json:"id"`
Birthday time.Time `json:"birthday"`
}
func (stu *Student) MarshalJSON() ([]byte, error) {
type TmpStudent Student
ts := struct {
Birthday string `json:"birthday"`
*TmpStudent
}{Birthday: stu.Birthday.Format(format),
TmpStudent: (*TmpStudent)(stu)}
return json.Marshal(ts)
}
func (stu *Student) UnmarshalJSON(data []byte) error {
type TmpStudent Student
ts := struct {
Birthday string `json:"birthday"`
*TmpStudent
}{Birthday: stu.Birthday.Format(format),
TmpStudent: (*TmpStudent)(stu)}
if err := json.Unmarshal(data, &ts); err != nil {
return err
}
var err error
stu.Birthday, err = time.ParseInLocation(format, ts.Birthday, time.Local)
return err
}
func main() {
s := Student{
Id: 1,
Birthday: time.Now(),
}
//序列化
marshal, err := json.Marshal(&s)
fmt.Println(string(marshal), err)
//-------------------------------
//反序列化
str:=`{"birthday":"2022-02-11 10:58:06","id":9999}`
_ = json.Unmarshal([]byte(str), &s)
fmt.Printf("s:%#v\n", s)
}