---
title:  Implement the IDataSerializable Interface
---

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To store your own data types in the cache, you implement the <%=vars.product_name%> `IDataSerializable` interface.

Examples follow the procedure.

**Procedure**

1.  Implement the `ToData` function that serializes your data:

    ``` pre
    void ToData(DataOutput output)
    ```

    The `ToData` function is responsible for copying all of the data fields for the object to the object stream. The `DataOutput` class represents the output stream and provides methods for writing the primitives in a network byte order.

2.  Implement the `FromData` function that consumes a data input stream and repopulates the data fields for the object:

    ``` pre
    void fromData (DataInput& input)
    ```

    The `DataInput` class represents the input stream and provides methods for reading input elements. The `FromData` function must read the elements of the input stream in the same order that they were written by `ToData`.

3.  Implement the `ClassId` function to return an integer which is unique for your class (in the set of all of your user-defined classes).

## Simple BankAccount Class

This example shows a simple class, `BankAccount`, that encapsulates the two `ints`, `customerId` and `accountId`:

``` pre
public class BankAccount
{
   private int m_customerId;
   private int m_accountId;
   public int Customer
   {
      get
      {
         return m_customerId;
      }
   }
   public int Account
   {
      get
      {
         return m_accountId;
      }
   }
   public BankAccount(int customer, int account)
   {
      m_customerId = customer;
      m_accountId = account;
   }
}
```

## Implementing a Serializable Class

To make `BankAccount` serializable, you implement the `IDataSerializable` interface as shown in this example:

``` pre
public class BankAccount : IDataSerializable
   {
   private int m_customerId;
   private int m_accountId;
   public int Customer
   {
      get
      {
         return m_customerId;
      }
   }
   public int Account
   {
      get
      {
         return m_accountId;
      }
   }
   public BankAccount(int customer, int account)
   {
      m_customerId = customer;
      m_accountId = account;
   }
   // Our TypeFactoryMethod
   public static IDataSerializable CreateInstance()
   {
      return new BankAccount(0, 0);
   }
   #region IDataSerializable Members
   public void ToData(DataOutput output)
   {
      output.WriteInt32(m_customerId);
      output.WriteInt32(m_accountId);
   }
   public void FromData(DataInput input)
   {
      m_customerId = input.ReadInt32();
      m_accountId = input.ReadInt32();
      return this;
   }
   public UInt32 ClassId
   {
      get
      {
         return 11;
      }
   }
   public UInt32 ObjectSize
   {
      get
      {
         return (UInt32)(sizeof(Int32) + sizeof(Int32));
      }
   }
}
```