Wednesday, June 25, 2008

Access Cache object of one application from another application OR share Cache object between Applications

       Recently while reading some forum I found an interesting question Can we share the cache object between two different applications ? More specifically can we access cache data of one application from another application ? I thought its a good topic to study and share.

       The answer is yes you can share the cache data between two application or you can access cache data of one application in another. There may be plenty of options to achieve this. The way I found and like is to serialize the cache data and transfer it between two applications.

       In the example which I will show here, I have created a two applications. First application has two pages Default.aspx and SerializeCacheData.aspx. The second application has only one page GetSerializedCacheData.aspx. The logic is, we will add the data in Cache on Default.aspx. SerializeCacheData.aspx page receives the name of the cache object we want to share between two applications. GetSerializedCacheData.aspx call the SerializeCacheData.aspx page and passes the name of the cache data that it wants from first application in querystring.

      On Default.aspx page I am creating an object of Person class (I have created a class in App_Code folder and will store the object of that class in cache) and string it is Cache. To store the object in Cache that object must be serializable. So I have marked my Person class as [Serializale]. Below is the Person class,

   1: using System;
   2: using System.Data;
   3: using System.Configuration;
   4: using System.Linq;
   5: using System.Web;
   6: using System.Web.Security;
   7: using System.Web.UI;
   8: using System.Web.UI.HtmlControls;
   9: using System.Web.UI.WebControls;
  10: using System.Web.UI.WebControls.WebParts;
  11: using System.Xml.Linq;
  12:  
  13: /// <summary>
  14: /// Summary description for Person
  15: /// </summary>
  16: [Serializable]
  17: public class Person
  18: {
  19:     public Person()
  20:     {
  21:         //
  22:         // TODO: Add constructor logic here
  23:         //
  24:         Name = "Chirag";
  25:         Address = "Ahmedabad";
  26:         Id = 1;
  27:         strPrivateData = "chirag";
  28:     }
  29:  
  30:     public string Name { get; set;}
  31:     public string Address { get; set; }
  32:     public int Id { get; set; }
  33:  
  34:     private string strPrivateData;
  35:  
  36: }

Fig - (1) Person class, we are going to store its object in Cache


       On Default.aspx page we will store the object of person class in cache as shown below,



   1: using System;
   2: using System.Configuration;
   3: using System.Data;
   4: using System.Linq;
   5: using System.Web;
   6: using System.Web.Security;
   7: using System.Web.UI;
   8: using System.Web.UI.HtmlControls;
   9: using System.Web.UI.WebControls;
  10: using System.Web.UI.WebControls.WebParts;
  11: using System.Xml.Linq;
  12:  
  13: public partial class _Default : System.Web.UI.Page 
  14: {
  15:     protected void Page_Load(object sender, EventArgs e)
  16:     {
  17:         if (!Page.IsPostBack)
  18:         {
  19:             Person objPerson = new Person { Name = "Dipak", Address = "USA", Id = 2 };
  20:             Cache.Insert("TestData", objPerson);
  21:         }
  22:     }
  23: }

Fig - (2) Storing data in Cache.


        On SerializeCacheData.aspx page we will serialize the cache data in byte array.  We will get the name of cache data in querystring.  As you can see in code below we will get the querystring parameter "data" on this page. We will retrieve the values from cache using querystring parameter and serialize it in Memory Stream. There is no need to store value in ViewState however I have specifically stored in ViewState as I need to do some operations on postback which I have not covered in this article. Look at the code below,



   1: using System;
   2: using System.Collections;
   3: using System.Configuration;
   4: using System.Data;
   5: using System.Linq;
   6: using System.Web;
   7: using System.Web.Security;
   8: using System.Web.UI;
   9: using System.Web.UI.HtmlControls;
  10: using System.Web.UI.WebControls;
  11: using System.Web.UI.WebControls.WebParts;
  12: using System.Xml.Linq;
  13: using System.Runtime.Serialization;
  14: using System.Runtime.Serialization.Formatters.Binary;
  15: using System.IO;
  16:  
  17: public partial class SerializeCacheData : System.Web.UI.Page
  18: {
  19:     public MemoryStream objMemoryStream
  20:     {
  21:         get
  22:         {
  23:             if (ViewState["objMemoryStream"] == null)
  24:                 ViewState["objMemoryStream"] = new MemoryStream();
  25:             return (MemoryStream)ViewState["objMemoryStream"];
  26:         }
  27:  
  28:         set
  29:         {
  30:             ViewState["objMemoryStream"] = value;
  31:         }
  32:     }
  33:     
  34:  
  35:     protected void Page_Load(object sender, EventArgs e)
  36:     {
  37:         if (!Page.IsPostBack)
  38:         {
  39:             string strValueToSerialize = string.Empty;
  40:  
  41:             // Get the name of Cache data from querystring
  42:             if (Request.QueryString["data"] != null)
  43:                 strValueToSerialize = Request.QueryString["data"].ToString();
  44:  
  45:             if (strValueToSerialize != string.Empty)
  46:             {
  47:                 // Serialize the data in Memory Stream
  48:                 IFormatter objIFormatter = new BinaryFormatter();
  49:                 objIFormatter.Serialize(objMemoryStream, Cache[strValueToSerialize]);
  50:                 objMemoryStream.Position = 0;
  51:  
  52:                 // Generate the byte array from Memory Stream
  53:                 byte[] objByte = new byte[objMemoryStream.Length];
  54:                 objMemoryStream.Read(objByte, 0, Convert.ToInt32(objMemoryStream.Length));
  55:                 Response.BinaryWrite(objByte);
  56:                 objMemoryStream.Position = 0;
  57:                 Response.End();
  58:             }
  59:             
  60:         }
  61:         
  62:     }
  63: }

Fig - (3) SerializeCacheData.aspx.cs


      Now in second application from GetSerializedCacheData.aspx page we will call SerializCacheData.aspx page and retrieves the value. Look at the code below,



   1: using System;
   2: using System.Collections;
   3: using System.Configuration;
   4: using System.Data;
   5: using System.Linq;
   6: using System.Web;
   7: using System.Web.Security;
   8: using System.Web.UI;
   9: using System.Web.UI.HtmlControls;
  10: using System.Web.UI.WebControls;
  11: using System.Web.UI.WebControls.WebParts;
  12: using System.Xml.Linq;
  13: using System.Net;
  14: using System.IO;
  15: using System.Runtime.Serialization;
  16: using System.Runtime.Serialization.Formatters.Binary;
  17:  
  18: public partial class GetSerilizedCacheData : System.Web.UI.Page
  19: {
  20:     protected void Page_Load(object sender, EventArgs e)
  21:     {
  22:         if (!Page.IsPostBack)
  23:         {
  24:             // Generate WebRequest to SerializeCacheData.aspx page
  25:             WebRequest objWebRequest = WebRequest.Create("http://localhost:1083/SerializationEx/SerializeCacheData.aspx?data=TestData");
  26:             WebResponse objWebResponse = objWebRequest.GetResponse();
  27:             Stream objStream = objWebResponse.GetResponseStream();
  28:  
  29:             // Deserialize the value
  30:             IFormatter objIFormatter = new BinaryFormatter();
  31:             Person objPerson = (Person)objIFormatter.Deserialize(objStream);
  32:             Response.Write(objPerson.Name);
  33:             
  34:         }
  35:     }
  36: }

Fig - (4) GetSerializedCacheData.aspx.cs


     As shown in above code, we are retrieving the Person class object in second application and writing the Name value in response. You must have to have Person class in both application. In real time you can pass anything which can be serialized like DataTable, DataSet or any custom object.


Happy Programming !!!

2 comments:

Anonymous said...

hmmm. Good article. But could you tell me the real time scenario where we need of this?

girija said...

Yesterday i want to chat with you.
But you are busy so not possible to chat with you.
And you told me to sent a comment that one
I am sending the detail pls review this as u r the TL i think u ll do this so pls help me ASAP.
my self girija prasad singh from orissa,bhubanswar working at enfinet technology.

Problem

I have one problem.My client told me to do one such type of project through which he is able to control the
header section of any project.
i have given u the detail information that.
my client is craig.He gave me one project which i have done this and the name is flashslideshow.;for ref check this link-http://flashdemo.interfinet.com/Login.aspx

1->when login u found two part that is header part and intros part .click the header part you will go headergridimageshow.aspx then u click the previewsection which is present left side of manage content.

2->There u find one flash and some contorl which are place on this flash like-gps.om2007@gmail.com,9861424194,Enfinet like this 6 controls .you will drag them through mouse. Then click the fixitem button which is present below of this page.Then u ll go to another page that is previewheaderfixitem.aspx.

3->There u find one publishselection link which is present above of the flash.When click this link one more window will open.

But client i mean craig told me that
suppose one customer came for one project to craig,for this project header part craig take the help of this project that i have done.It means he change the flash size and the control which is present on flash (6 controls ).And when he click the publish selection one more window will not open rather the flash and control are placed from the header part of this customer whose header part controlled by craig.
simillary as number of customer came for them craig take the help of this project that i have
done and controlled the header section.

It means
There is the back end admin section that allows the admin to make changes to the flash header
when it is done the customer should be able to see these changes on the website of his project

so how should i do this,when i ll change the header it will reflect on my project but he told that it will reflct from customer project .
so it needs to pass the flash file ,xml file and the database to another project thai i m not doing.

N.B-(Actually the flash size and the controls are change but i m not saying u that how to do this)

If u have done that type of project pls help me or if u dont understand my problem then sent me mail i ll again tell you but i need the solution ASAP.