DELPHI 6 DEVELOPER’S GUIDE
Arrays ............................................................................................944
Sequences ......................................................................................944
Method Arguments ........................................................................945
Modules ........................................................................................945
The Bank Example ............................................................................946
Complex Data Types ..........................................................................958
Delphi, CORBA, and Enterprise Java Beans (EJBs) ........................965
A Crash Course in EJBs for Delphi Programmers ......................965
An EJB Is a Specialized Component ............................................966
EJBs Live Within a Container ......................................................966
EJBs Have Predefined APIs ..........................................................966
The Home and Remote Interfaces ................................................966
Types of EJBs ................................................................................967
Configuring JBuilder 5 for EJB Development ..............................967
Building a Simple “Hello, world” EJB ........................................968
CORBA and Web Services ................................................................975
Creating the Web Service ..............................................................975
Creating the SOAP Client Application ........................................977
Adding the CORBA Client Code to the Web Service ..................978
Summary ............................................................................................981
20 BizSnap Development: Writing SOAP-Based Web Services 983
What Are Web Services? ....................................................................984
What Is SOAP? ..................................................................................984
Writing a Web Service ........................................................................985
A Look at the TWebModule ..........................................................985
Defining an Invokable Interface ....................................................986
Implementing an Invokable Interface ............................................987
Testing the Web Service ................................................................989
Invoking a Web Service from a Client ..............................................991
Generating an Import Unit for the Remote Invokable Object ......993
Using the THTTPRIO Component ..............................................994
Summary ............................................................................................995
21 DataSnap Development 997
Mechanics of Creating a Multitier Application ..................................998
Benefits of the Multitier Architecture ................................................999
Centralized Business Logic ..........................................................999
Thin-Client Architecture ..............................................................1000
Automatic Error Reconciliation ..................................................1000
Briefcase Model ..........................................................................1000
Fault Tolerance ............................................................................1000
Load Balancing ............................................................................1000
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