CFEverywhere Part 3

After somewhat of a hiatus, we're back to continue and conclude our CFEverywhere journey. I should note that Dick Applebaum, my copilot for parts 1 and 2, was unable to join me for this last installment. It won't be the same without his contribution but we'll have to make do. Moreover, as Dick provided the knowledge for the Mac side of things, I'll have to apologize in advance for the lack of detail on that front.

In the previous articles, we demonstrated how to deploy a CFML application into a self-contained package. We used BlueDragon, Jetty, and Derby to create a fully dynamic, database-driven application running locally, giving the appearance of a traditional desktop application. Now I'll deliver the final piece of the puzzle and demonstrate how to create an application launcher to deliver the ultimate user experience. To access your application, the user will be able to:

  1. Download the application (or insert a CD)
  2. Double-click an icon
  3. That's it - there is no Step 3!
Up to now we've been starting Jetty and Derby from the command line by invoking the Java runtime and passing the appropriate JAR files. To make our own application bundle, we'll create some simple Java classes that wrap the necessary Jetty and Derby classes. If you're not familiar with Java don't be intimidated. What we'll do is fairly straightforward and may be a good opportunity to get familiar with working with Java (in so far as it pertains to your CF projects). If you want to compile the Java source, you'll need the Java SDK installed on your system. You can get the SDK at http://java.sun.com/j2se/1.4.2/download.html. Please note that although you may have a Java Runtime Environment (JRE) installed, this is different from the SDK and doesn't have the necessary tools to compile Java code and create JAR files. It's also helpful to have a Java IDE at your disposal. Eclipse is a popular Java IDE that's readily available. You can download it from www.eclipse.org.

Create a new project folder called cfeverywherej to contain the files for the Java project. Create a file cfeverywere.java that looks like Listing 1. Let's take a look at the main method of this class. It begins by initializing some variables. It continues on to instantiate a JettyThread class and calls its run method. Looking at Listing 2, we see that JettyThread is a simple class that extends Thread. Its run method checks if the isStarted flag has been set. If not, it starts Jetty using the org.mortbay.jetty.Server class. After the JettyThread is created Derby is started in a similar fashion using the DerbyThread class (see Listing 3). After JettyThread and DerbyThread are created, we wait an amount of time defined by delayMilliseconds that allows time for the servers to initialize and get ready to accept requests. Finally, the Web browser is launched to the application URL using a platform specific command. In order to compile the class files, you will need to make sure the following jar files are on your build path:

cfeverywhere/server/lib/org.mortbay.jetty.jar
   cfeverywhere/derby/lib/derbynet.jar

After you have compiled the Java class files, create a JAR file by using the JAR utility:

On Windows:
C:\j2sdk1.4.2_04\bin\jar.exe -cvf cfeverywhere.jar *.class

On Mac OS X:
C:\j2sdk1.4.2_04\bin\jar.exe -cvf cfeverywhere.jar *.class

If you are using Eclipse, you can create the JAR file by choosing Export from the File menu and choosing JAR file. Copy the cfeverywhere.jar file to the cfeverywhere project folder. We now have the Java classes required to create our application bundle. The process to create the application launcher is different for each platform so we'll discuss them separately.

To create our application launcher on Windows, we will use a utility called NativeJ. Visit their Web site at www.dobysoft.com/products/nativej and download the trial version of the program. Install the software and start a new project. Configure the project with these settings:

Executable

Java Runtime Application A sample NativeJ project file is included with the source code for this article. From the File menu click Generate Executable and you will, well, generate an executable.

Double-click the executable, and you should see a command line window appear that shows the server starting up, and then your CFML application should launch in your browser. Pretty cool, huh?

If your CF page didn't display properly it may be that the servers didn't complete the startup procedure before the browser was launched. You may have to increase the delayMilliseconds value in cfeverywhere.java to allow more time. When you want to quit your application you can't simply close the browser. You have to CTRL-C in the command line window and that will initiate a shutdown of the servers.

To create an application bundle on the Mac, you can use the same Java code to create the JAR file. Instead of NativeJ you would use the JarBundler application that is distributed with other developer tools for OSX, which are located at Developer/Applications. Configure JarBundler with the cfeverywhere.jar file and set the classpath similar to how NativeJ was configured; click "Create Application..." and you will have your Mac application bundle. This process is described in more detail in this article: http://java.sun.com/developer/technicalArticles/JavaLP/JavaToMac3/.

Launching from an HTA File
One aspect of the Java/NativeJ launcher that some folks might find undesirable is the appearance of the command window (and perhaps the license fee). On the CFEverywhere mailing list, Adam Haskell shared a great tip on how to use an HTA (HTML Application) file to create a CFE launcher that doesn't create a command line window. You can learn more about HTA at http://msdn.microsoft.com/library/default.asp?url=/ workshop/author/hta/overview/htaoverview.asp (see Listing 4). When you double-click the cfeverywhere.hta file, the VBScript block executes, which instantiates an instance of the Wscript.Shell. This object allows you to execute the batch files to start Jetty and Derby. In order to give the servers time to start, we load a wait.html (Listing 5) in an iframe. Wait.html displays a loading animated gif and uses a meta-fresh to load the application page after a set time. When you want to quit, simply close the application/browser window and the onUnload() event will shutdown Jetty and Derby. It's a Windows-only solution but it works quite nicely and the price is right.

Creating a CFEverywhere CD
Creating a CD is really quite simple. For the entire process, we have been careful to only use relative paths when referring to files. All of the server components are designed to work in a read-only mode. Before we create the CD, let's set it up to automatically run our CFML application when the disc is inserted. Download AutoRun.exe and place it in the cfeverywhere folder. Create a text file called autorun.inf with these contents:

[autorun]
OPEN=autorun.exe cfeverywhere.hta

If you have a custom icon you can add:

    icon=myicon.ico

To make a CD, simply create a project that contains everything in the cfeverywhere folder and burn the CD. Insert the CD on another computer (that has a Java runtime) and try it out. Note that starting a J2EE server and database server from CD is not the quickest thing in the world. You may have to set the wait time in wait.html to upwards of 20 seconds or more depending on the system. Regardless, it brings a smile to you face the first time you put a CD of your application in the computer and see your app launch.

Conclusion
Well, now you have all the tools and knowledge to create your own CFEverywhere applications. I hope this sparks your imagination and inspires you to try it out. If you do create a CFEverywhere application please share your experience on the CFEverywhere mailing list.

Resources

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