Go实战--xml与json相互转换(The way to go)

生命不止，继续 go go go !

之前写了两篇博客，分别介绍了go中的encoding/json和encoding／xml，有很多相识之处。

json和xml的恩恩怨怨还没有结束，在实战中我们会用到XML与json的相互转化，没有太难懂的地方。

xml转json

package mainimport (    "encoding/json"    "encoding/xml"    "fmt")type DataFormat struct {    ProductList []struct {        Sku      string `xml:"sku" json:"sku"`        Quantity int    `xml:"quantity" json:"quantity"`    } `xml:"Product" json:"products"`}func main() {    xmlData := []byte(`<?xml version="1.0" encoding="UTF-8" ?><ProductList>    <Product>        <sku>ABC123</sku>        <quantity>2</quantity>    </Product>    <Product>        <sku>ABC123</sku>        <quantity>2</quantity>    </Product></ProductList>`)    data := &DataFormat{}    err := xml.Unmarshal(xmlData, data)    if nil != err {        fmt.Println("Error unmarshalling from XML", err)        return    }    result, err := json.Marshal(data)    if nil != err {        fmt.Println("Error marshalling to JSON", err)        return    }    fmt.Printf("%s\n", result)}

输出：
{“products”:[{“sku”:”ABC123”,”quantity”:2},{“sku”:”ABC123”,”quantity”:2}]}

xml文件转json文件
接下来，我们根据一个xml文件生产一个相应的json文件。
在src文件夹下mkdir xmlfile_to_jsonfile，新建一个一个XML文件：

Employees.xml

<?xml version="1.0"?>  <company>          <staff>                  <id>101</id>                  <firstname>Derek</firstname>                  <lastname>Young</lastname>                  <username>derekyoung</username>          </staff>          <staff>                  <id>102</id>                  <firstname>John</firstname>                  <lastname>Smith</lastname>                  <username>johnsmith</username>          </staff>  </company>

代码：

package main import (         "encoding/json"         "encoding/xml"         "fmt"         "io/ioutil"         "os" ) type jsonStaff struct {         ID        int         FirstName string         LastName  string         UserName  string } type Staff struct {         XMLName   xml.Name `xml:"staff"`         ID        int      `xml:"id"`         FirstName string   `xml:"firstname"`         LastName  string   `xml:"lastname"`         UserName  string   `xml:"username"` } type Company struct {         XMLName xml.Name `xml:"company"`         Staffs  []Staff  `xml:"staff"` } func (s Staff) String() string {         return fmt.Sprintf("\t ID : %d - FirstName : %s - LastName : %s - UserName : %s \n", s.ID, s.FirstName, s.LastName, s.UserName) } func main() {         xmlFile, err := os.Open("Employees.xml")         if err != nil {                 fmt.Println("Error opening file:", err)                 return         }         defer xmlFile.Close()         XMLdata, _ := ioutil.ReadAll(xmlFile)         var c Company         xml.Unmarshal(XMLdata, &c)         // sanity check - XML level         fmt.Println(c.Staffs)         // convert to JSON         var oneStaff jsonStaff         var allStaffs []jsonStaff         for _, value := range c.Staffs {                 oneStaff.ID = value.ID                 oneStaff.FirstName = value.FirstName                 oneStaff.LastName = value.LastName                 oneStaff.UserName = value.UserName                 allStaffs = append(allStaffs, oneStaff)         }         jsonData, err := json.Marshal(allStaffs)         if err != nil {                 fmt.Println(err)                 os.Exit(1)         }         // sanity check - JSON level         fmt.Println(string(jsonData))         // now write to JSON file         jsonFile, err := os.Create("./Employees.json")         if err != nil {                 fmt.Println(err)         }         defer jsonFile.Close()         jsonFile.Write(jsonData)         jsonFile.Close() }

生成了文件Employees.json ：

[     {         "ID": 101,         "FirstName": "Derek",         "LastName": "Young",         "UserName": "derekyoung"     },     {         "ID": 102,         "FirstName": "John",         "LastName": "Smith",         "UserName": "johnsmith"     } ]

json转xml

type Person struct {    Id        int    `xml:"id,attr"`    FirstName string `xml:"name>first" json:"first"`    LastName  string `xml:"name>last" json:"last"`}func main() {    j := `{"id": 10, "first": "firstname", "last":"lastname"}`    var p Person    fmt.Println(json.Unmarshal([]byte(j), &p), p)    out, _ := xml.MarshalIndent(p, "\t", "\t")    fmt.Println(string(out))}