如何将所有解码的数据写入JSON文件？

Question

I try to parse an XML data to a JSON file, but when I begin writing marshaled data to a JSON, it just rewrites data in the JSON file and, as a result, I have the file with last XML element. How to write the whole data into the JSON file?

Snippet of code that parses XML and marshal data to JSON

    decoder := xml.NewDecoder(file)
    resultData := map[string]map[string]string{}
    for {
        t, _ := decoder.Token()
        if t == nil {
            break
        }

        switch et := t.(type) {
        case xml.StartElement:
            if et.Name.Local == "profile" {
                var object XMLProfile
                decoder.DecodeElement(&object, &et)

                resultData = map[string]map[string]string{
                    object.ProfileName: {},
                }

                for _, val := range object.Fields {
                    resultData[object.ProfileName][val.Name] = val.Value
                }
            }
        }
    }

    if out, err := json.MarshalIndent(resultData, "", "\t"); err != nil {
        panic(err)
    } else {
        _ = ioutil.WriteFile("test.json", out, 0644)
    }

Expect JSON:

{
  "Profile 1": {
      "role": "user"
  },

  "Profile 2": {
      "role": "user"
  },

  "Profile 3": {
      "role": "admin"
  }
}

Actual JSON:

{
  "Profile 3": {
    "role": "admin"
  }
}

Answer 1

Seems like you are recreating the resultData after each iteration in the nodes named "profile". As that happens, only the last one will reach the code where you write the JSON.

Try this:

decoder := xml.NewDecoder(file)
resultData := map[string]map[string]string{}
for {
    t, _ := decoder.Token()
    if t == nil {
        break
    }

    switch et := t.(type) {
    case xml.StartElement:
        if et.Name.Local == "profile" {
            var object XMLProfile
            decoder.DecodeElement(&object, &et)

            resultData[object.ProfileName] = map[string]string{}

            for _, val := range object.Fields {
                resultData[object.ProfileName][val.Name] = val.Value
            }
        }
    }
}

if out, err := json.MarshalIndent(resultData, "", "\t"); err != nil {
    panic(err)
} else {
    _ = ioutil.WriteFile("test.json", out, 0644)
}

I would also check if no duplicate ProfileName happens to appear in the XML, as it would override the previous entry.