Distributed application (below) using dynamic call mode (below)
(This article is reproduced from Software Engineering Expert Network www.21cmm.com)
Su Yang
The last lecture introduces the creation of the client dynamic call interface (DII) and service object dynamic skeleton interface (DSI) using dynamic call mode, using a specific example to explain the entire process.
1. Summary function description and system brief design
This example still simulates a telecommunications tariff management business process, and register a telephone user on the service object. The user queries the user's call for this month at the remote client. According to the instructions of the object function, use UML to describe the functions that the service object needs to be implemented:
Getfee (): float
OpenAccout: Agent
2. Service object interface definition
According to the system analysis results, use IDL to write the service object method description program Telecomm.IDL:
Module Telecomm
{
Interface Agent
{
Float getfee ();
}
Interface AgentManager
{
Account OpenAccount (in string name);
}
}
3. Implementation of the interface
(1) Realization of Agent interface
Public Class AgentImpl Extends DynamicImplementation
{
// Construct an AgentImpl class
// GET method In the invoke dynamic call method, press name matching call
Public synchronized org.omg.corba.object get (String name) {
// Apply for an account amount, generate an account object
}
Public void invoke (org.omg.corba.serverRequest request) {
// Apply a portable object adapter
// Fill in the calling parameters, put forward the application account request
}
}
(2) AgentManager interface implementation
Public class agentmanagerImpl Extends DynamicImPlementation {
// Construct an AgentManager class
Public void invoke (org.omg.corba.serverRequest request) {
// Fill in the calling parameter table, propose a business request to the Agent object, get an Agent object
// ......
}
}
(3) Server-side programming
Public class server {
Public static void main (String [] args) {
// Initialize ORB, apply for POA and POA Manager
// Apply for a default service object, activate the POA manager
// Waiting for the call request
// ......
}
(4) Client programming
Public class client {
Public static void main (String [] args) {
// Initialize ORB, locate the AgentManager object
/ / Send a call request
Org.omg.corba.Request Request = Manager ._Request ("getfee");
Request.invoke ();
// Query return result, get the return value
Request.get_Response ();
// abnormal processing
// ......
}
4. Program design and operational environment
The above-described dynamic call interface and the dynamic skeleton interface is based on the Visibroker 4.5.1 middleware environment. The implementation of the program in other environments may be different. In the Visibroker environment, run the program as follows:
(1) First launch the Visibroker Smart Agent transaction agent;
(2) Start the service object program: VBJ Server; (3) Start the customer object program: VBJ Client.
Where VBJ is the Java code interpretation executor in Visibroker For Java. The reader can also replace the Java interpretation tool Java, but you need to specify Vbjorb in Visibroker.
