The main tool detailed in this chapter is VisualAge for Java for Windows NT, Enterprise Edition, which is an end-to-end Java application development tool that lets you develop Java code on the workstation and deploy it on OS/390. It provides a comprehensive Integrated Development Environment (IDE) that supports browsing, editing, compiling, testing, debugging, and deployment. The Enterprise Toolkit for OS/390 (ET/390), a feature of VisualAge for Java Enterprise Edition, provides OS/390 support. It provides a SmartGuide to export class files to the OS/390 Hierarchical File System (HFS) for native compilation and debugging. Native code built on PDSEs is a dynamic link library (DLL) that, while not portable, is suited for high-performance server programs.

This section shows how to prepare your Windows NT environment before you start developing your CORBA application using VisualAge for Java. The CICS ORB classes and the JCICS APIs are shipped with VisualAge for Java 3.0 Enterprise Edition as additional features. If you are working with Version 2.0, you need to copy the required packages from the CD-ROM that accompanies this book, set up the CICS IDL environment, and configure the ET/390 environment, as explained here:

Figure 7-1 shows the results of this procedure, including the JCICS beans:

@@HPJHostName:  Host machine address
@@HPJHome: /u/hpj/extract.spe23/hpj.dev
@@HPJBinderExecutablesPDSE: HPJ.R14.TOBEY.JAV2R0M0.SPE23
@@HPJBinderMessagesPDSE: HPJ.R14.TOBEY
@@HPJLERuntimeBind: PP.ADLE370.OS39025.SCEELKED:PP.ADLE370.OS39025.SCEELKEX:PP.
ADLE370.OS39025.SCEEOBJ:PP.ADLE370.OS39025.SCEECPP
@@HPJLERuntimeRun: PP.ADLE370.OS39025.SCEERUN
@@HPJRuntime: HPJ.BUILD.JAV2R0M0.SPE23.LOAD
@@HPJDebugger: HPJ.DEBUG.VISUAL.SEQAMOD
@@HPJProfiler:
@@HPJJavaHome: /usr/lpp/java114/J1.1
@@HPJPICLHome:
@@HPJCICSRegion: regionName
@@HPJCICSEXCI: CTS130.GA3.CICS.SDFHEXCI

This procedure describes how to write the IDL definition and operations that generate the necessary classes for a customer account object.

If you haven’t done this already, create a KanDoIT Server project in your VisualAge for Java Workbench. From the main menu bar, select File and Quickstart (or press F2), highlight Basic and Create project, and click OK. Enter the project name in the Create a new project named: field and click Finish.

To make life easier for you, we’ll describe the import process and use the files that we have supplied on the CD-ROM. The procedure below imports the accountObject.idl file which is part of the sample application. To import an existing IDL into the project:

module accountObject {
          string respcode;
          string reascode;
          string cicsfunc;
          string acctid;
          string lastname;
          string firstname;
          string midinit;
          string title;
          string telnum;
          string addr1;
          string addr2;
          string addr3;
          string auth1;
          string auth2;
          string auth3;
          string auth4;
          string cards;
          string issuemonth;
          string issueday;
          string issueyear;
          string reason;
          string code;
          string approver;
          string scode1;
          string scode2;
          string scode3;
          string status;
          string limit;
  };
  interface AccountInterface {
      //getter methods
      accountObject::AccountData getAccount(in string acctno);
   };

Once the IDL definition has been imported, invoke the CICS IDL-to-Java compiler to compile it in the form of both stub and skeleton code. The VisualAge for Java IDL development environment lets you specify compiler options before you invoke the compiler:

If no errors occur, one or more Java classes and interfaces are generated for the IDL objects contained in AccountIDL group. The Java classes and interface are displayed in the Types pane.

Now all the server skeletons and helper classes are generated, you can move on to write the server implementation class. At this point you should return to the main Workbench window and select your project (in our case, the KanDoIT Server project).

You create the server application by extending the base implementation class, _AccountInterfaceImplBase, which is generated by the IDL compiler as seen in Example 7-3. The class name of the server implementation must be _AccountInterfaceImpl.

/**
accountObject/_AccountInterfaceImplBase.java
* Generated by the IBM IDL-to-Java compiler, version 1.0
* from accountObject.idl
* 25 February 2000 18:22:35 o'clock GMT-05:00
*/

public abstract class _AccountInterfaceImplBase extends com.ibm.CORBA.portable.
ObjectImpl implements accountObject.AccountInterface, com.ibm.CORBA.portable.Skeleton
{
  private static com.ibm.CORBA.portable.OperationDescriptor __dispatchTable[][] = new
com.ibm.CORBA.portable.OperationDescriptor[1][0];

  static {
__dispatchTable[0] = accountObject._AccountInterfaceStub._get_operations ();
  }

  // Type-specific CORBA::Object operations
  private static String[] __ids = {
"IDL:accountObject/AccountInterface:1.0"  };
}

In the Workbench you will see that there are a number of classes and one interface created in the accountObject package. You can see the list in Figure 7-6. The interface was created as a result of the interface defined in the IDL called AccountInterface. The interface contains one method called getAccount method. We will be implementing the getAccount method in our implementation class and that is expecting to receive an account number and return the AccountData structure.

Figure 7-6. VisualAge for Java: Workbench showing the classes of the accountObject package

import com.ibm.cics.server.*;
import java.io.*;
/**
 * This type was created in VisualAge.
 */
public class _AccountInterfaceImpl extends _AccountInterfaceImplBase {
     CommAreaHolder crudCA;
     Program cobolProg;
}

An Implementation class for the sample application is supplied on the CD-ROM. Import the file called _AccountInterfaceImpl.java into your project as follows:

The .java file will be compiled into bytecode and the package is created under the KanDoIT Server project. This adds a further class to the accountObject class and extends the _AccountInterfaceImplBase class that was generated from the IDL definition. You can view the source code for the class and see the methods it contains. Examples Example 7-4 through Example 7-7 show the resulting code. Figure 7-8 shows the resulting structure.

Figure 7-8. VisualAge for Java: Workbench

public byte[] buildCA(String value)   {
     ByteArrayOutputStream baos = new ByteArrayOutputStream();
     try  {
          DataOutputStream dos = new DataOutputStream(baos);
          OutputStreamWriter osw = new OutputStreamWriter(dos);
         // add a character string big enough to hold returned COMMAREA
         // This is a long string of spaces the same length as the returned COMMAREA
         // Note This line has been shortened in this example to fit the page
         // Your data will be truncated.  You should use the code from the CD-ROM
         osw.write(value + "                                                  ");
         osw.flush();
         dos.flush();
          }   catch (Exception e) {
     System.err.println("Unable to build commarea");
     System.err.println(">" + e.toString());
     }
     return baos.toByteArray();
}

At this point you have extended the base classes generated from the IDL and provided an implementation class to build a request COMMAREA, converted it to byte array format, performed the link to the COBOL program, retrieved account data, and returned it to the calling program. The accountObject package now needs to be deployed in a CICS region. ET/390 uses FTP to export class files on OS/390. You should have already mounted a drive on your machine using an NFS client, which points to your host.

In the VisualAge for Java Workbench:

Any output from the bind is written to the VisualAge for Java log window. If the export and bind fails, access your host system and you will see a bin file in /tmp. Copy this to the subdirectory where you are saving your classes and run it with the Unix Services Shell on OS/390 to determine what is wrong.

So far we have created the IDL definition, written the server-side application and exported that application to an OS/390 server. Now we need to write a CORBA client to test the CORBA server code that we have just created.

Figure 7-11. VisualAge for Java: ET/390 Properties for object accountObject

Normally there are two steps:

/**
 * This method was created in VisualAge.
 * @param ai accountObject.AccountInterface
 */
public void getDetails(accountObject.AccountInterface ai, String acctID) {
          // Invoke the getAccount method
          System.out.println("Client: invoking getAccount method on accountObject
object");
          AccountData acctData = ai.getAccount(acctID);
         if (acctData.respcode.equals("0000") && acctData.reascode.equals("0000"))  {
               System.out.println("Account ID: " + acctData.acctid);
               System.out.println("First name: " + acctData.firstname);
               System.out.println("Last name: " + acctData.lastname);
               System.out.println("Mid init: " + acctData.midinit);
               System.out.println("Title: " + acctData.title);
               System.out.println("Tel Number: " + acctData.telnum);
               System.out.println("Address 1: " + acctData.addr1);
               System.out.println("Address 2: " + acctData.addr2);
               System.out.println("Address 3: " + acctData.addr3);
               System.out.println("Auth 1: " + acctData.auth1);
               System.out.println("Auth 2: " + acctData.auth2);
               System.out.println("Auth 3: " + acctData.auth3);
               System.out.println("Auth 4: " + acctData.auth4);
               System.out.println("Cards: " + acctData.cards);
               System.out.println("Issue Date: " + acctData.issueday + "/" +
                                  acctData.issuemonth + "/" + acctData.issueyear);
               System.out.println("Reason: " + acctData.reason);
               System.out.println("Code: " + acctData.code);
               System.out.println("Approver: " + acctData.approver);
               System.out.println("Scode 1: " + acctData.scode1);
               System.out.println("Scode 2: " + acctData.scode2);
               System.out.println("Scode 3: " + acctData.scode3);
               System.out.println("Status: " + acctData.status);
               System.out.println("Limit: " + acctData.limit);
         } else {                                             // non-zero return code
              System.out.println("An error occurred: ");
              System.out.println("Response Code: " + acctData.respcode);
              System.out.println("Reason Code: " + acctData.reascode);
              System.out.println("Account ID: " + acctData.acctid);
              System.out.println("CICS Function: " + acctData.cicsfunc);
           }
}

Testing the Client

To test the client, select the RunClient class and click the running man button on the toolbar. The console panel should appear with output from the ClientStub class. See Figure 7-21 for a sample output.

Figure 7-19. VisualAge for Java: Class Path for RunClient

Figure 7-20. VisualAge for Java: Properties for RunClient

Figure 7-21. VisualAge for Java: The Console Panel

So now we have a working CORBA application in which our test client, running in the VisualAge for Java IDE is invoking methods on the accountObject object running in the CICS region. To build a complete web application, we now need to incorporate our CORBA client into a web server environment. This allows KanDoIT customers to retrieve their account data from the Web using their browsers. This is described in detail in Part IV.