Using JCICS

Use the classes from the JCICS library in the same way as Java™ classes. Applications declare a reference of the required type and a new instance of a class is created using the new operator.

Name CICS® resources using the setName method to supply the name of the underlying CICS resource. After creating the resource, manipulate objects using standard Java constructs. Call methods of the declared objects in the usual way. Full details of the methods supported for each class are available in the supplied Javadoc.

CICS attempts to pass control to the method with a signature of main(CommAreaHolder) in the class specified by the JVMCLASS attribute of the PROGRAM resource. If this method is not found, CICS tries to invoke method main(String[]).

For more information, see Java restrictions and JCICS Javadoc information.

This example shows how to create a TSQ object, invoke the delete method on the temporary storage queue object you have just created, and catch the thrown exception if the queue is empty.

// Define a package name for the program
package unit_test;

// Import the JCICS package
import com.ibm.cics.server.*;

// Declare a class for a CICS application
public class JCICSTSQ
{
    // The main method is called when the application runs
    public static void main(CommAreaHolder cah)
    {
        try
        {
            // Create and name a Temporary Storage queue object
            TSQ tsq = new TSQ();
            tsq.setName("JCICSTSQ");

            // Delete the queue if it exists
            try
            {
                tsq.delete();
            }
            catch(InvalidQueueIdException e)
            {
                // Absorb QIDERR
                System.out.println("QIDERR ignored!");
            }

            // Write an item to the queue
            String transaction = Task.getTask().getTransactionName();
            String message = "Transaction name is - " + transaction;
            tsq.writeItem(message.getBytes());
        }
        catch(Throwable t)
        {
            System.out.println("Unexpected Throwable: " + t.toString());
        }

        // Return from the application
        return;
    }
}