Question

我正在尝试连接到一个api，它从WCF服务（WCF服务到WCF服务）返回GZip编码的JSON。我使用 HTTPClient 连接到API，并且能够将JSON对象作为字符串返回。但是我需要能够将这些返回的数据存储在数据库中，因此我认为最好的方法是将JSON对象返回并存储在数组或字节中或沿着这些行存储。

我遇到的问题是GZip编码的解压缩，并尝试了很多不同的例子，但仍然无法得到它。

以下代码是我建立连接和获取响应的方式，这是从API返回字符串的代码。

public string getData(string foo)
{
    string url = "";
    HttpClient client = new HttpClient();
    HttpResponseMessage response;
    string responseJsonContent;
    try
    {
        client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
        response = client.GetAsync(url + foo).Result;
        responseJsonContent = response.Content.ReadAsStringAsync().Result;
        return responseJsonContent;
    }
    catch (Exception ex)
    {
        System.Windows.Forms.MessageBox.Show(ex.Message);
        return "";
    }
}

我一直在关注一些不同的例子，比如这些StackExchange API，MSDN和一些关于stackoverflow的例子，但是我无法让这些对我有用。

实现这一目标的最佳方法是什么，我是否在正确的轨道上？

谢谢你们。

Answer 1

只需像这样实例化HttpClient：

HttpClientHandler handler = new HttpClientHandler()
{
    AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate
};

using (var client = new HttpClient(handler))
{
    // your code
}

Answer 2

好的，所以我最终解决了我的问题。如果有更好的方法请告诉我： - ）

        public DataSet getData(string strFoo)
    {
        string url = "foo";

        HttpClient client = new HttpClient();
        HttpResponseMessage response;   
        DataSet dsTable = new DataSet();
        try
        {
               //Gets the headers that should be sent with each request
            client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
              //Returned JSON
            response = client.GetAsync(url).Result;
              //converts JSON to string
            string responseJSONContent = response.Content.ReadAsStringAsync().Result;
              //deserializes string to list
            var jsonList = DeSerializeJsonString(responseJSONContent);
              //converts list to dataset. Bad name I know.
            dsTable = Foo_ConnectAPI.ExtentsionHelpers.ToDataSet<RootObject>(jsonList);
              //Returns the dataset                
            return dsTable;
        }
        catch (Exception ex)
        {
            System.Windows.Forms.MessageBox.Show(ex.Message);
            return null;
        }
    }

       //deserializes the string to a list. Utilizes JSON.net. RootObject is a class that contains the get and set for the JSON elements

    public List<RootObject> DeSerializeJsonString(string jsonString)
    {
          //Initialized the List
        List<RootObject> list = new List<RootObject>();
          //json.net deserializes string
        list = (List<RootObject>)JsonConvert.DeserializeObject<List<RootObject>>(jsonString);

        return list;
    }

RootObject包含将获取JSON值的get集。

public class RootObject
{  
      //These string will be set to the elements within the JSON. Each one is directly mapped to the JSON elements.
      //This only takes into account a JSON that doesn't contain nested arrays
    public string EntityID { get; set; }

    public string Address1 { get; set; }

    public string Address2 { get; set; }

    public string Address3 { get; set; }

}

创建上述类的最简单方法是使用json2charp，它会相应地格式化它，并提供正确的数据类型。

以下内容来自Stackoverflow的另一个答案再次，它没有考虑嵌套的JSON。

    internal static class ExtentsionHelpers
{
    public static DataSet ToDataSet<T>(this List<RootObject> list)
    {
        try
        {
            Type elementType = typeof(RootObject);
            DataSet ds = new DataSet();
            DataTable t = new DataTable();
            ds.Tables.Add(t);

            try
            {
                //add a column to table for each public property on T
                foreach (var propInfo in elementType.GetProperties())
                {
                    try
                    {
                        Type ColType = Nullable.GetUnderlyingType(propInfo.PropertyType) ?? propInfo.PropertyType;

                            t.Columns.Add(propInfo.Name, ColType);

                    }
                    catch (Exception ex)
                    {
                        System.Windows.Forms.MessageBox.Show(ex.Message);
                    }

                }
            }
            catch (Exception ex)
            {
                System.Windows.Forms.MessageBox.Show(ex.Message);
            }

            try
            {
                //go through each property on T and add each value to the table
                foreach (RootObject item in list)
                {
                    DataRow row = t.NewRow();

                    foreach (var propInfo in elementType.GetProperties())
                    {
                        row[propInfo.Name] = propInfo.GetValue(item, null) ?? DBNull.Value;
                    }

                    t.Rows.Add(row);
                }
            }
            catch (Exception ex)
            {
                System.Windows.Forms.MessageBox.Show(ex.Message);
            }

            insert.insertCategories(t);
            return ds.
        }
        catch (Exception ex)
        {
            System.Windows.Forms.MessageBox.Show(ex.Message);

            return null;
        }
    }
};

然后最后将上面的数据集插入到一个表中，该表包含映射到JSON的列，我使用的是SQL批量复制和下面的类

public class insert
{ 
    public static string insertCategories(DataTable table)
    {     
        SqlConnection objConnection = new SqlConnection();
          //As specified in the App.config/web.config file
        objConnection.ConnectionString = System.Configuration.ConfigurationManager.ConnectionStrings["foo"].ToString();

        try
        {                                 
            objConnection.Open();
            var bulkCopy = new SqlBulkCopy(objConnection.ConnectionString);

            bulkCopy.DestinationTableName = "dbo.foo";
            bulkCopy.BulkCopyTimeout = 600;
            bulkCopy.WriteToServer(table);

            return "";
        }
        catch (Exception ex)
        {
            System.Windows.Forms.MessageBox.Show(ex.Message);
            return "";
        }
        finally
        {
            objConnection.Close();
        }         
    }
};

因此，上述方法可以将WebAPI中的JSON插入到数据库中。这是我开始工作的东西。但我绝不期望它是完美的。如果您有任何改进，请相应更新。

Answer 3

我使用下面链接中的代码解压缩GZip流，然后使用解压缩的字节数组获取所需的JSON对象。希望对您有所帮助。

https://www.dotnetperls.com/decompress

var readTask = result.Content.ReadAsByteArrayAsync().Result;
var decompressedData = Decompress(readTask);
string jsonString = System.Text.Encoding.UTF8.GetString(decompressedData, 0, decompressedData.Length);
ResponseObjectClass responseObject = Newtonsoft.Json.JsonConvert.DeserializeObject<ResponseObjectClass>(jsonString);

从HTTPClient响应中解压缩GZip流

3 个答案: