Building Java Applications for the iSeries Server with VisualAge for Java 3.5

Chapter 9. Moving the server application to Java 365

We directly export the classes using the VisualAge for Java export function. When we run the

application on the iSeries server, we have to set the CLASSPATH environment variable to

include the IFS file directory where we stored the class files. In Figure 9-23, we export the

classes to the iSeries server using a network drive.

Figure 9-23 Exporting the class files

9.4.5 Implementing the client

This section explains how to build the client class of the RMI application. We create a new

class that is a subclass of javax.swing.JFrame and implements the PartsContainer interface.

This class uses the ToolboxGUI class as re-usable part. For details about the ToolboxGUI

class and the PartsContainer interface, refer to 4.6.5, “Reusable GUI part” on page 170.

The name of the client program is RMIExample. As shown in Figure 9-24, we create global

variables for the port name and system name and create a new instance of the ItemSubmitter

class, which we call remoteRequestor. We use the remoteRequestor object for all of our RMI

work.

Figure 9-24 Creating the client class

public class RMIExample extends javax.swing.JFrame implements

DatabaseAccessExample.PartsContainer, java.awt.event.WindowListener

{

private DatabaseAccessExample.ToolboxGUI ivjToolboxGUI1 = null;

static java.lang.String port = null;

static java.lang.String systemName;

ItemSubmitter remoteRequestor = new ItemSubmitter();

366 Building Java Applications for the iSeries Server with VisualAge for Java 3.5

The RMIExample main method (Figure 9-25) was created by VisualAge for Java.

Figure 9-25 RMIExample main() method

When the application is run, the main() method instantiates a new instance of the

RMIExample class. We only have to modify it to use the first argument of the parameter list to

set the port variable.

The connectToDB() method shown in Figure 9-26 is executed when the user clicks the

Connect button.

Figure 9-26 RMIExample connectToDB() method

We use the system name from the screen TextField as a parameter to set the systemName

variable. We call the linked() method of the remoteRequestor object, which was instantiated

from the ItemSubmitter class to establish the RMI connection.

The getRecord() method, shown in Figure 9-27, is called when the user clicks the Get Part

button.

public static void main(java.lang.String[] args) {

if ((port = args[0]) != null)

{

try {

RMIExample aRMIExample;

aRMIExample = new RMIExample();

aRMIExample.addWindowListener(new java.awt.event.WindowAdapter() {

public void windowClosing(java.awt.event.WindowEvent e) {

System.exit(0);

};

});

aRMIExample.show();

java.awt.Insets insets = aRMIExample.getInsets();

aRMIExample.setSize(aRMIExample.getWidth() + insets.left + insets.right,

aRMIExample.getHeight() + insets.top + insets.bottom);

aRMIExample.setVisible(true);

} catch (Throwable exception) {

System.err.println("Exception occurred in main() of javax.swing.JFrame");

exception.printStackTrace(System.out);

}

}

else

{

System.out.println("Please Input port number");

}

}

public void connectToDB(String systemName, String userid, String password) throws

Exception {

this.systemName = systemName;

remoteRequestor.linked(systemName, port);

return;

}

Chapter 9. Moving the server application to Java 367

Figure 9-27 RMIExample getRecord() method

The getRecord() method calls the submit() method of the remoteRequestor object passing

the part number as a parameter. An Item object is returned that contains the details about the

Item (or Part).

If an Item object is returned, the item requested was found in the database. We use the getter

methods provided by the Item object to retrieve the information and display it on the screen.

The populateAllParts() method, shown in Figure 9-28, is called when the user clicks the

Get All Parts button. It calls the submitAll() method of the remoteRequestor object passing

no parameters.

Figure 9-28 RMIExample populateAllParts() method

public String getRecord(String partNo, javax.swing.JTextField partDesc,

javax.swing.JTextField partQty, javax.swing.JTextField partPrice,

javax.swing.JTextField partDate) throws Exception {

Item rtnItem = remoteRequestor.submit(partNo);

if ((rtnItem) != null)

{

partDesc.setText(rtnItem.getItemDesc());

partDate.setText(rtnItem.getItemDate());

partQty.setText((Integer.toString(rtnItem.getItemQuantity())));

partPrice.setText("$" + (rtnItem.getItemPrice()).toString());

}

else {

partDesc.setText("");

partDate.setText("");

partQty.setText("");

partPrice.setText("");

return "Record not found";

}

return "Record found";

}

public void populateAllParts(javax.swing.table.DefaultTableModel defaultTableModel)

throws Exception

{

Item rtnItem = remoteRequestor.submitAll();

if (rtnItem != null) {

for (int i = 0; i < rtnItem.getNumEntries(); i++) {

ItemDetail rtnDetail = rtnItem.getNextEntry(i);

String[] array = new String[5];

array[0] = rtnDetail.getItemId();

array[1] = rtnDetail.getItemDsc();

array[2] = rtnDetail.getItemPrice();

array[3] = rtnDetail.getItemQty();

array[4] = rtnDetail.getItemDate();

defaultTableModel.addRow(array);

}

}

return;

}