Golang操作结构体、Map转化为JSON

结构体生成Json

package main import ( "encoding/json"
    "fmt" ) type IT struct { Company string `json:"-"` //此字段不会输出到屏幕 //Company string `json:"company"` 这样打印输出别名首字母就会小写(二次编码)
    Subjects []string `json:"subjects"` //二次编码
    IsOk     bool     `json:",string"` Price float64 `json:",string"` }
 func main() { //定义一个结构体变量，同时初始化
    s := IT{"itcast", []string{"Golang", "PHP", "Java", "C++"}, true, 666.666} //编码，根据内容生成json文本 //buf, err := json.Marshal(s) //buf = {"subjects":["Golang","PHP","Java","C++"],"IsOk":"true","Price":"666.666"}
    buf, err := json.MarshalIndent(s, "", "    ") //格式化编码
    if err != nil { fmt.Println("err = ", err) return } fmt.Println("buf = ", string(buf)) }

//结果
buf = { "subjects": [   //首字母小写
               "Golang", "PHP", "Java", "C++" ], "IsOk": "true",   //string类型
       "Price": "666.666" }

Json转成结构体

package main import ( "encoding/json"
    "fmt" ) type IT struct { Address string   `json:"address"` Languages []string `json:"languages"` //二次编码
    Status    bool     `json:"isok"` Price float64 `json:"price"` } func main() { jsonBuf := ` { "address": "北京", "languages": [ "Golang", "PHP", "Java", "Python" ], "status": true, "price": 666.666 }` var tmp IT                                   //定义一个结构体变量
    err := json.Unmarshal([]byte(jsonBuf), &tmp) //第二个参数要地址传递
    if err != nil { fmt.Println("err = ", err) return } //fmt.Println("tmp = ", tmp)
    fmt.Printf("tmp = %+v\n", tmp) type IT2 struct { Subjects []string `json:"languages"` //二次编码
 } var tmp2 IT2 err = json.Unmarshal([]byte(jsonBuf), &tmp2) //第二个参数要地址传递
    if err != nil { fmt.Println("err = ", err) return } fmt.Printf("tmp2 = %+v\n", tmp2) }

tmp = {Address:北京 Languages:[Golang PHP Java Python] Status:false Price:666.666} tmp2 = {Subjects:[Golang PHP Java Python]}

Map生成Json

package main import ( "encoding/json"
    "fmt" ) func main() { //创建一个map
    m := make(map[string]interface{}, 4) //因为类型多，可以用interface空接口
    m["address"] = "北京" m["languages"] = []string{"Golang", "PHP", "Java", "Python"} m["status"] = true m["price"] = 666.666

    //编码成json //result, err := json.Marshal(m) //result = {"address":"北京","languages":["Golang","PHP","Java","Python"],"price":666.666,"status":true}
    result, err := json.MarshalIndent(m, "", "    ") if err != nil { fmt.Println("err = ", err) return } fmt.Println("result = ", string(result)) }

result = { "address": "北京", "languages": [ "Golang", "PHP", "Java", "Python" ], "price": 666.666, "status": true }

Json转化为Map

package main import ( "encoding/json"
    "fmt" ) func main() { jsonBuf := ` { "company": "itcast", "subjects": [ "Go", "C++", "Python", "Test" ], "isok": true, "price": 666.666 }` //创建一个map
    m := make(map[string]interface{}, 4) err := json.Unmarshal([]byte(jsonBuf), &m) //第二个参数要地址传递
    if err != nil { fmt.Println("err = ", err) return } fmt.Printf("m = %+v\n", m) // var str string // str = string(m["company"]) //err， 无法转换 // fmt.Println("str = ", str)

    var str string

    //类型断言, 值，它是value类型
    for key, value := range m { //fmt.Printf("%v ============> %v\n", key, value)
        switch data := value.(type) { case string: str = data fmt.Printf("map[%s]的值类型为string, value = %s\n", key, str) case bool: fmt.Printf("map[%s]的值类型为bool, value = %v\n", key, data) case float64: fmt.Printf("map[%s]的值类型为float64, value = %f\n", key, data) case []string: fmt.Printf("map[%s]的值类型为[]string, value = %v\n", key, data) case []interface{}: fmt.Printf("map[%s]的值类型为[]interface, value = %v\n", key, data) } } }

map[address]的值类型为string, value = 北京 map[Languages]的值类型为[]interface, value = [Golang PHP Java Python] map[Status]的值类型为bool, value = true map[price]的值类型为float64, value = 666.666000

 实际项目中建议参考此链接博文：

https://www.kutu66.com//GitHub/article_108925#10-yfsys