[C#.NET] 如何利用 JSON API 分析 IP Location

當我們知道一個IP Address後要如何更進一步的知道這個IP的資訊??在網路上爬了一段文，得知可以使用 http://ipinfodb.com/index.php 所提供的API來處理，這個網頁提供了XML API以及JSON API，很可惜站上並無.NET的範例程式碼，只好自己動手處理，原理很簡單，只要送出WebResquest後就能取得結果。

我們可以利用這個查詢字串，送出WebResquest，它就會回傳相關欄位了，下圖是它回傳的欄位

程式開始前必須要向官網申請Key http://ipinfodb.com/register.php

建立欄位類別

[Serializable]
public class JsonIpinfodbLocationField
{
    public string StatusCode { get; set; }
    public string StatusMessage { get; set; }
    public string ipAddress { get; set; }
    public string CountryCode { get; set; }
    public string CountryName { get; set; }
    public string RegionName { get; set; }
    public string CityName { get; set; }
    public string ZipCode { get; set; }
    public string Latitude { get; set; }
    public string Longitude { get; set; }
    public string TimeZone { get; set; }
}

---

使用Json API

鍵入以下程式碼：

public JsonIpinfodbLocationField GetIpDetail(string ipAddress)
{
    string ip = string.Empty;
    Encoding sourceEncoding = Encoding.UTF8;
    string connectString = string.Format("http://api.ipinfodb.com/v3/ip-city/?key={0}&ip={1}&format=json", "輸入自己申請的Key", ipAddress);

    StringBuilder ipInfo = new StringBuilder();
    Stream webStream = null;
    StreamReader streamReader = null;
    try
    {
        //1.取得Response串流
        webStream = WebRequest.Create(connectString).GetResponse().GetResponseStream();
        streamReader = new StreamReader(webStream, sourceEncoding);
        //2.分批讀取到StringBuilder
        char[] buffer = new char[256];
        int readLength = streamReader.Read(buffer, 0, buffer.Length);
        while (readLength > 0)
        {
            byte[] dataArray = sourceEncoding.GetBytes(buffer, 0, readLength);
            ipInfo.Append(sourceEncoding.GetString(dataArray));
            readLength = streamReader.Read(buffer, 0, buffer.Length);
        }
        //3.利用JavaScriptSerializer反序列化處理Json
        JavaScriptSerializer scriptSerializer = new JavaScriptSerializer();
        object obj = scriptSerializer.Deserialize<JsonIpinfodbLocationField>(ipInfo.ToString());

        return obj as JsonIpinfodbLocationField;
    }
    finally
    {
        if (webStream != null)
            webStream.Close();
        if (streamReader != null)
            streamReader.Close();
    }
}

PS.上面程式碼是分批讀取，當然也可以直接用streamReader.ReadToEnd方法讀取全部。

還沒有反序列化前的資料長這樣，看起來得再處理一下。

透過 JavaScriptSerializer 反序列化後得到了正確的結果，省掉了做苦工的時間。

PS.使用JavaScriptSerializer類別時，必須要手動加入參考：System.Web.Extensions.dll

---

使用XML API

把json換成xml

public JsonIpinfodbLocationField GetIpDetail(string ipAddress)
{
    string ip = string.Empty;
    Encoding sourceEncoding = Encoding.UTF8;
    string connectString = string.Format("http://api.ipinfodb.com/v3/ip-city/?key={0}&ip={1}&format=xml", "輸入自己申請的Key", ipAddress);

    StringBuilder ipInfo = new StringBuilder();
    Stream webStream = null;
    StreamReader streamReader = null;
    try
    {
        //1.取得Response串流
        webStream = WebRequest.Create(connectString).GetResponse().GetResponseStream();
        streamReader = new StreamReader(webStream, sourceEncoding);
        //2.分批讀取到StringBuilder
        char[] buffer = new char[256];
        int readLength = streamReader.Read(buffer, 0, buffer.Length);
        while (readLength > 0)
        {
            byte[] dataArray = sourceEncoding.GetBytes(buffer, 0, readLength);
            ipInfo.Append(sourceEncoding.GetString(dataArray));
            readLength = streamReader.Read(buffer, 0, buffer.Length);
        }
        //3.讀取xml
        return getXmlFormat(ipInfo.ToString());
    }
    finally
    {
        if (webStream != null)
            webStream.Close();
        if (streamReader != null)
            streamReader.Close();
    }
}

ipInfo 會得到XML結構，我試了一下，這個結構並沒有辦法可以直接反序列化的方式，如果有人試出來了麻煩告知我一下。

所以我就利用 XDocument 讀取  Xml

JsonIpinfodbLocationField getXmlFormat(string ipInfo)
{
    JsonIpinfodbLocationField field = new JsonIpinfodbLocationField();
    XDocument doc = XDocument.Parse(ipInfo);

    field.CityName = doc.Elements().Select(a => a.Element("cityName").Value).FirstOrDefault();
    field.CountryCode = doc.Elements().Select(a => a.Element("countryCode").Value).FirstOrDefault();
    field.CountryName = doc.Elements().Select(a => a.Element("countryName").Value).FirstOrDefault();
    field.ipAddress = doc.Elements().Select(a => a.Element("ipAddress").Value).FirstOrDefault();
    field.Latitude = doc.Elements().Select(a => a.Element("latitude").Value).FirstOrDefault();
    field.Longitude = doc.Elements().Select(a => a.Element("longitude").Value).FirstOrDefault();
    field.RegionName = doc.Elements().Select(a => a.Element("regionName").Value).FirstOrDefault();
    field.StatusCode = doc.Elements().Select(a => a.Element("statusCode").Value).FirstOrDefault();
    field.StatusMessage = doc.Elements().Select(a => a.Element("statusMessage").Value).FirstOrDefault();
    field.TimeZone = doc.Elements().Select(a => a.Element("timeZone").Value).FirstOrDefault();
    field.ZipCode = doc.Elements().Select(a => a.Element("zipCode").Value).FirstOrDefault();

    return field;
}

最後所得到以下結果。

---

後記：

除了http://ipinfodb.com/index.php外還有一個網站也提供了相關的功能http://freegeoip.net/static/index.html，用法都大同小益

---

補充：

Xml沒辦法轉的原因是我自己的問題，本以為透過Stream直接反序列就好了，沒想到事實上並不是這樣

XmlSerializer xml = new XmlSerializer(typeof(JsonIpinfodbLocationField));
object obj = xml.Deserialize(streamReader);

重新定義Entity類別

[Serializable]
[XmlRoot("Response")]
public class JsonIpinfodbLocationField
{
    [XmlElement("statusCode")]
    public string StatusCode { get; set; }

    [XmlElement("statusMessage")]
    public string StatusMessage { get; set; }

    [XmlElement("ipAddress")]
    public string IpAddress { get; set; }

    [XmlElement("countryCode")]
    public string CountryCode { get; set; }

    [XmlElement("countryName")]
    public string CountryName { get; set; }

    [XmlElement("regionName")]
    public string RegionName { get; set; }

    [XmlElement("cityName")]
    public string CityName { get; set; }

    [XmlElement("zipCode")]
    public string ZipCode { get; set; }

    [XmlElement("latitude")]
    public string Latitude { get; set; }

    [XmlElement("longitude")]
    public string Longitude { get; set; }

    [XmlElement("timeZone")]
    public string TimeZone { get; set; }
}

改寫Method，將字串 data 丟到 MemoryStream 再反序列化即可

public JsonIpinfodbLocationField GetIpDetail(string ipAddress)
{
    string ip = string.Empty;
    Encoding sourceEncoding = Encoding.UTF8;
    string connectString = string.Format("http://api.ipinfodb.com/v3/ip-city/?key={0}&ip={1}&format=xml", "輸入申請的KEY", ipAddress);

    StringBuilder ipInfo = new StringBuilder();
    Stream webStream = null;
    StreamReader streamReader = null;
    try
    {
        //1.取得Response串流
        webStream = WebRequest.Create(connectString).GetResponse().GetResponseStream();
        streamReader = new StreamReader(webStream, sourceEncoding);
        //2.分批讀取到StringBuilder
        char[] buffer = new char[256];
        int readLength = streamReader.Read(buffer, 0, buffer.Length);
        while (readLength > 0)
        {
            byte[] dataArray = sourceEncoding.GetBytes(buffer, 0, readLength);
            ipInfo.Append(sourceEncoding.GetString(dataArray));
            readLength = streamReader.Read(buffer, 0, buffer.Length);
        }
        string data = ipInfo.ToString();

        byte[] byteArray = sourceEncoding.GetBytes(data);
        MemoryStream memoryStream = new MemoryStream(byteArray);

        XmlSerializer xml = new XmlSerializer(typeof(JsonIpinfodbLocationField));
        object obj = xml.Deserialize(memoryStream);
  
        return obj as JsonIpinfodbLocationField;
    }
    finally
    {
        if (webStream!=null)
            webStream.Close();
        if (streamReader!=null)
            streamReader.Close();
    }
}

再此感謝91哥的回覆。