Now that you understand the functionality of the application and
have defined the business processes, the next step is to identify the backend
system transaction messages and the data that is to be kept in the Electronic
Journal.
For the Customer Search transaction, the following information
is sent to the backend system:
- Transaction identifier (TX01)
- Customer identifier
The reply from the Customer Search transaction includes the following
information:
- Reply code
- Customer name
- Account list data (defined as an AccountList type that contains the Account
type), which includes the following account information fields:
- Account Number
- Type
- Name
- Balance
These four fields are needed to accommodate the HTML client demo.
- Error message (to give information about the error in case of failure;
if the reply code is OK, the error message is meaningless)
For the Withdrawal and Deposit transactions, the following information
is sent to the backend system:
- Transaction identifier (TX02 for withdrawal, TX03 for deposit)
- Account number
- Date
- Amount
The reply from the Withdrawal and the Deposit transactions includes
the following information:
- Reply code
- Account balance
- Error message
For the Account Statement transaction, the following information is
sent to the backend system:
- Transaction identifier (TX04)
- Account number
The reply from the Account Statement transaction includes the following
information:
- Reply code
- A list of entries with the following data:
- Date
- Operation description
- Amount
- Account balance
- Error message
The information to be sent to the backend system must be in a format
that can be understood by the backend system application. In the Java
(TM) Client
Sample Application, each field in the buffer must be preceded by a field identifier,
and fields must be separated from each other using the delimiter #. The following
is an example of a formatted buffer for a withdrawal operation:
TX02AN=10011004217460000041#DT=18072000#AM=10000#BR=1005#
where TX02 is the transaction type identifier for withdrawal transactions,
and AN, DT, AM, and BR are the field identifiers for the Account Number, Date,
Amount, and Branch Identifier fields, respectively.
The information
will be saved in the dummy Electronic Journal. The application writes an entry
in the dummy Electronic Journal before sending data to the backend system,
and that entry is updated with the backend system reply after the reply is
received.
The following information is kept in the journal:
- Added before information has been sent to the backend system:
- User identification
- Terminal identification
- The data to be sent
- Added after the backend system response has been received: