1. JSON

• json是完全独立于语言的文本格式，是k-v的形式 name:zs
• 应用场景：前后端交互，系统间数据交互

• json使用go语言内置的encoding/json 标准库
• 编码json使用json.Marshal()函数可以对一组数据进行JSON格式的编码

    func Marshal(v interface{}) ([]byte, error)

示例过结构体生成json

package mainimport ("encoding/json""fmt"
)type Person struct {Name  stringHobby string
}func main() {p := Person{"5lmh.com", "女"}// 编码jsonb, err := json.Marshal(p)if err != nil {fmt.Println("json err ", err)}fmt.Println(string(b))// 格式化输出b, err = json.MarshalIndent(p, "", "     ")if err != nil {fmt.Println("json err ", err)}fmt.Println(string(b))
}

struct tag

    type Person struct {//"-"是忽略的意思Name  string `json:"-"`Hobby string `json:"hobby" `}

示例通过map生成json

package mainimport ("encoding/json""fmt"
)func main() {student := make(map[string]interface{})student["name"] = "5lmh.com"student["age"] = 18student["sex"] = "man"b, err := json.Marshal(student)if err != nil {fmt.Println(err)}fmt.Println(b)
}

• 解码json使用json.Unmarshal()函数可以对一组数据进行JSON格式的解码

    func Unmarshal(data []byte, v interface{}) error

示例解析到结构体

package mainimport ("encoding/json""fmt"
)type Person struct {Age       int    `json:"age,string"`Name      string `json:"name"`Niubility bool   `json:"niubility"`
}func main() {// 假数据b := []byte(`{"age":"18","name":"5lmh.com","marry":false}`)var p Personerr := json.Unmarshal(b, &p)if err != nil {fmt.Println(err)}fmt.Println(p)
}

示例解析到interface

package mainimport ("encoding/json""fmt"
)func main() {// 假数据// int和float64都当float64b := []byte(`{"age":1.3,"name":"5lmh.com","marry":false}`)// 声明接口var i interface{}err := json.Unmarshal(b, &i)if err != nil {fmt.Println(err)}// 自动转到mapfmt.Println(i)// 可以判断类型m := i.(map[string]interface{})for k, v := range m {switch vv := v.(type) {case float64:fmt.Println(k, "是float64类型", vv)case string:fmt.Println(k, "是string类型", vv)default:fmt.Println("其他")}}
}

2. XML

• 是可扩展标记语言，包含声明、根标签、子元素和属性
• 应用场景：配置文件以及webService

示例：

    <?xml version="1.0" encoding="UTF-8" ?><servers version="1"><server><serverName>Shanghai_VPN</serverName><serverIP>127.0.0.1</serverIP></server><server><serverName>Beijing_VPN</serverName><serverIP>127.0.0.2</serverIP></server></servers>

package mainimport ("encoding/xml""fmt""io/ioutil"
)// 抽取单个server对象
type Server struct {ServerName string `xml:"serverName"`ServerIP   string `xml:"serverIP"`
}type Servers struct {Name    xml.Name `xml:"servers"`Version int   `xml:"version"`Servers []Server `xml:"server"`
}func main() {data, err := ioutil.ReadFile("D:/my.xml")if err != nil {fmt.Println(err)return}var servers Serverserr = xml.Unmarshal(data, &servers)if err != nil {fmt.Println(err)return}fmt.Printf("xml: %#v\n", servers)
}

3. MSGPack

• MSGPack是二进制的json，性能更快，更省空间
• 需要安装第三方包：go get -u github.com/vmihailenco/msgpack

package mainimport ("fmt""github.com/vmihailenco/msgpack""io/ioutil""math/rand"
)type Person struct {Name stringAge  intSex  string
}// 二进制写出
func writerJson(filename string) (err error) {var persons []*Person// 假数据for i := 0; i < 10; i++ {p := &Person{Name: fmt.Sprintf("name%d", i),Age:  rand.Intn(100),Sex:  "male",}persons = append(persons, p)}// 二进制json序列化data, err := msgpack.Marshal(persons)if err != nil {fmt.Println(err)return}err = ioutil.WriteFile(filename, data, 0666)if err != nil {fmt.Println(err)return}return
}// 二进制读取
func readJson(filename string) (err error) {var persons []*Person// 读文件data, err := ioutil.ReadFile(filename)if err != nil {fmt.Println(err)return}// 反序列化err = msgpack.Unmarshal(data, &persons)if err != nil {fmt.Println(err)return}for _, v := range persons {fmt.Printf("%#v\n", v)}return
}func main() {//err := writerJson("D:/person.dat")//if err != nil {// fmt.Println(err)// return//}err := readJson("D:/person.dat")if err != nil {fmt.Println(err)return}
}