WebService传输大数据量时的操作

(1)直接返回DataSet对象

 特点:通常组件化的处理机制,不加任何修饰及处理;

 优点:代码精减、易于处理,小数据量处理较快;

 缺点:大数据量的传递处理慢,消耗网络资源;

 建议:当应用系统在内网、专网(局域网)的应用时,或外网(广域网)且数据量在KB级时的应用时,采用此种模式。

  示例代码如下:

 1       [WebMethod(Description = "直接返回 DataSet 对象。")]
 2     public DataSet GetNorthwindDataSet()
 3     {
 4         string sql = "SELECT * FROM XT_TEXT";
 5         SqlConnection conn = new SqlConnection("Server=60.28.25.58;DataBase=s168593;user id=s168593;password=h0y+FeC*;");
 6         conn.Open();
 7         SqlDataAdapter dataadapter = new SqlDataAdapter(sql, conn);
 8         DataSet ds = new DataSet();
 9         dataadapter.Fill(ds, "XT_TEXT");
10         conn.Close();
11         return ds;
12      }
13

 客户程序代码调用方法:

private void button1_Click(object sender, EventArgs e)
{
    //com.dzbsoft.www是上面Web Service发布后的命名空间
    com.dzbsoft.www.Service1 ds = new com.dzbsoft.www.Service1();
    DateTime dtBegin = DateTime.Now;
    DataSet dataSet = ds.GetNorthwindDataSet();
    this.label1.Text = string.Format("耗时:{0}", DateTime.Now - dtBegin);
    binddata(dataSet);
}

 (2) 返回DataSet对象用Binary序列化后的字节数组

  特点:字节数组流的处理模式;
   优点:易于处理,可以中文内容起到加密作用;
   缺点:大数据量的传递处理慢,较消耗网络资源;
 
代码
[WebMethod(Description = "返回 DataSet 对象用 Binary 序列化后的字节数组。")]
    public byte[] GetDataSetBytes()
    {
        DataSet dataSet = GetNorthwindDataSet();
        BinaryFormatter ser = new BinaryFormatter();
        MemoryStream ms = new MemoryStream();
        ser.Serialize(ms, dataSet);
        byte[] buffer = ms.ToArray();
        return buffer;
}

 示例如下:

客户程序调用方法:
代码

private void button2_Click(object sender, EventArgs e)
{
    com.dzbsoft.www.Service1 ds = new com.dzbsoft.www.Service1();
    DateTime dtBegin = DateTime.Now;
    byte[] buffer = ds.GetDataSetBytes();
    BinaryFormatter ser = new BinaryFormatter();
    DataSet dataSet = ser.Deserialize(new MemoryStream(buffer)) as DataSet;
    this.label2.Text = string.Format("耗时:{0}", DateTime.Now - dtBegin) + "  " + buffer.Length;
    binddata(dataSet);
}

(3) 返回DataSetSurrogate对象用Binary序列化后的字节数组

特点:微软提供的开源组件;
下载地址:http://support.microsoft.com/kb/829740/zh-cn
优点:易于处理,可以中文内容起到加密作用;
缺点:大数据量的传递处理慢,较消耗网络资源;
示例代码如下:

 1 [WebMethod(Description = "返回 DataSetSurrogate 对象用 Binary 序列化后的字节数组。")]
 2     public byte[] GetDataSetSurrogateBytes()
 3     {
 4         DataSet dataSet = GetNorthwindDataSet();
 5         DataSetSurrogate dss = new DataSetSurrogate(dataSet);
 6         BinaryFormatter ser = new BinaryFormatter();
 7         MemoryStream ms = new MemoryStream();
 8         ser.Serialize(ms, dss);
 9         byte[] buffer = ms.ToArray();
10         return buffer;
11 }
12  

 客户程序调用方法:

 1 private void button3_Click(object sender, EventArgs e)
 2 {
 3     com.dzbsoft.www.Service1 ds = new com.dzbsoft.www.Service1();
 4     DateTime dtBegin = DateTime.Now;
 5     byte[] buffer = ds.GetDataSetSurrogateBytes();
 6     BinaryFormatter ser = new BinaryFormatter();
 7     DataSetSurrogate dss = ser.Deserialize(new MemoryStream(buffer)) as DataSetSurrogate;
 8     DataSet dataSet = dss.ConvertToDataSet();
 9     this.label3.Text = string.Format("耗时:{0}", DateTime.Now - dtBegin) + "  " + buffer.Length;
10     binddata(dataSet);
11 }
12  

(4)返回DataSetSurrogate对象用Binary序列化并Zip压缩后的字节数组
 特点:对字节流数组进行压缩后传递;
 优点:当数据量大时,性能提高效果明显,压缩比例大;
 缺点:相比第三方组件,压缩比例还有待提高;
 建议:当系统需要进行大数据量网络数据传递时,建议采用此种可靠、高效、免费的方法。

示例代码如下:


   [WebMethod(Description = "返回 DataSetSurrogate 对象用 Binary 序列化并 Zip 压缩后的字节数组。")]
    public byte[] GetDataSetSurrogateZipBytes()
    {
        DataSet dataSet = GetNorthwindDataSet();
        DataSetSurrogate dss = new DataSetSurrogate(dataSet);
        BinaryFormatter ser = new BinaryFormatter();
        MemoryStream ms = new MemoryStream();
        ser.Serialize(ms, dss);
        byte[] buffer = ms.ToArray();
        byte[] zipBuffer = Compress(buffer);
        return zipBuffer;
   }

    public byte[] Compress(byte[] data)
    {
        try
        {
            MemoryStream ms = new MemoryStream();
            Stream zipStream = null;
            zipStream = new GZipStream(ms, CompressionMode.Compress, true);
            zipStream.Write(data, 0, data.Length);
            zipStream.Close();
            ms.Position = 0;
            byte[] compressed_data = new byte[ms.Length];
            ms.Read(compressed_data, 0, int.Parse(ms.Length.ToString()));
            return compressed_data;
        }
        catch
        {
            return null;
        }
    }
}

  客户程序调用方法:

 1 private void button4_Click(object sender, EventArgs e)
 2 {
 3     com.dzbsoft.www.Service1 ds = new com.dzbsoft.www.Service1();
 4     DateTime dtBegin = DateTime.Now;
 5     byte[] zipBuffer = ds.GetDataSetSurrogateZipBytes();
 6     byte[] buffer = UnZipClass.Decompress(zipBuffer);
 7     BinaryFormatter ser = new BinaryFormatter();
 8     DataSetSurrogate dss = ser.Deserialize(new MemoryStream(buffer)) as DataSetSurrogate;
 9     DataSet dataSet = dss.ConvertToDataSet();
10     this.label4.Text = string.Format("耗时:{0}", DateTime.Now - dtBegin) + "  " + zipBuffer.Length;
11     binddata(dataSet);
12 }
13

private void binddata(DataSet dataSet)
{
    this.dataGridView1.DataSource = dataSet.Tables[0];
    this.label5.Text = "共计:" + dataSet.Tables[0].Rows.Count + "条记录";
}
 
 1 客户端UnZipClass程序
 2  public static class UnZipClass
 3 {
 4     public static byte[] Decompress(byte[] data)
 5     {
 6         try
 7         {
 8             MemoryStream ms = new MemoryStream(data);
 9             Stream zipStream = null;
10             zipStream = new GZipStream(ms, CompressionMode.Decompress);
11             byte[] dc_data = null;
12             dc_data = ExtractBytesFromStream(zipStream, data.Length);
13             return dc_data;
14         }
15         catch
16         {
17             return null;
18         }
19     }
20     public static byte[] ExtractBytesFromStream(Stream zipStream, int dataBlock)
21     {
22         byte[] data = null;
23         int totalBytesRead = 0;
24         try
25         {
26             while (true)
27             {
28                 Array.Resize(ref data, totalBytesRead + dataBlock + 1);
29                 int bytesRead = zipStream.Read(data, totalBytesRead, dataBlock);
30                 if (bytesRead == 0)
31                 {
32                     break;
33                 }
34                 totalBytesRead += bytesRead;
35             }
36             Array.Resize(ref data, totalBytesRead);
37             return data;
38         }
39         catch
40         {
41             return null;
42         }
43     }
44 }
45 

posted on 2012-05-03 15:40  Arrow.Lu  阅读(369)  评论(0)    收藏  举报