Java Reference
In-Depth Information
L
ISTING
9.14
Continued
<information>
<title>Installer Template</title>
<vendor>Mauro's Workshop</vendor>
<offline/>
</information>
<resources>
<j2se version=”1.2+” />
<jar href=”jnlpinstaller.jar” />
</resources>
<installer-desc main-class=”com.marinilli.b2.c9.JNLPInstaller” />
</jnlp>
Now, let's have a look at the Java classes involved. The installer is shown in Listing 9.15. It is
a typical example of using the
ExtensionInstallerService
class. It simply modifies the look
of the standard JNLP Client's download window, presenting a download procedure to the
user—only illustrative. Note that in the previously mentioned example (Listing 9.9), we hide
the standard JNLP download window; whereas here, we are customizing it for our application.
Depending on your needs and on the experience you want to transmit to users, you can decide
to display your own download window or to use the standard one that is more recognizable by
users. It requires less code to be handled, but can be less flexible in some situations.
L
ISTING
9.15
The jnlpinstaller-ext JNLP File
package com.marinilli.b2.c9;
import javax.jnlp.*;
/**
* Chapter 9 - Customizing the standard download window
* @author Mauro Marinilli
* @version 1.0
*/
public class JNLPInstaller {
ExtensionInstallerService eis;
public JNLPInstaller() {
try {
eis =
(ExtensionInstallerService)ServiceManager.lookup(“javax.jnlp.ExtensionInstaller
Service”);
} catch(UnavailableServiceException use) {
System.out.println(“Service not supported: “+use);
}
if (eis!=null) {
