Application Development

Chapter 9 . Connecting to the Middleware

Panther is a complete three-tier product containing all the client and server components needed in building applications. Clients and servers can reside on different machines connected by a network. The middleware controls communication between client and server components, making it possible for an application's clients to interact with the application's servers.

Panther can work with your choice of the following middleware packages:

JetNet and Oracle Tuxedo are TP monitor systems using messages and buffers to pass information to and from clients and application servers.

MTS for Windows, one of the deployment options for COM components, controls database connection pooling, transactions and security access for COM component packages.

IBM's WebSphere Application Server deploys Enterprise JavaBeans (EJBs), Java-based components, in a distributed application environment.

This chapter describes:

Using JetNet and Oracle Tuxedo

In JetNet and Oracle Tuxedo applications, the middleware performs the following tasks:

Opening a Middleware Session in the Editor

In JetNet/Oracle Tuxedo applications, you open a middleware session to connect to a middleware and access the libraries and repositories on the application server. The middleware controls processes and communication between the application's clients and servers. To test an application screen that uses services, you must have a valid middleware connection.

How to Open a Middleware Session

  1. Choose FileOpenMiddleware Session. The Connect dialog box appears.

    Figure 9-1 Connect to the middleware for a client on a server machine, also called a local or native client.

    For a local client on a server machine, the Connect dialog box has the following fields and specifications:

  2. Enter the information required in the appropriate fields depending on whether you are a client on a server machine or a PC client.

    If the application requires level-two authentication, then you must enter the application password in the Password field.

    Note: The level of authentication is decided at design time. Thus, a user should be aware of the decided authentication level.

Opening a Middleware Session Programmatically

To establish a middleware session programmatically, use the client_init command. For example, this statement opens a client connection and specifies an application password:

client_init PASSWORD appPassword

Refer to client_init for more information.

Using MTS

Since a COM component's entry in the Windows registry also specifies its machine location, the client application uses the same processing to call components on local and remote machines.

MTS is just one of the deployment options. COM components can be deployed using the following technologies:

For detailed information about deploying COM components, refer to Chapter 5, "Deploying COM Components," in COM/MTS Guide.

Using WebSphere Application Server

In WebSphere Application Server, you deploy EJBs on the WebSphere server machine. Clients in your application can then call methods and set properties on those EJBs. Clients in a Panther application can specify the WebSphere server using the provider_url application property.

For information on setting up Panther software in a WebSphere environment, refer to Chapter 2, "Configuring Machines," in Panther for IBM WebSphere Developer's Studio.