Ask the Java expert: Create a Java .exe file

Question
Hi Michael,
For my application I need to create a Java .exe. What steps do I need to create one? Is there a tool that will help me do this automatically?

Answer
The standard Java development kit (JDK) supplied by Sun does not provide a tool to create platform specific executables (This is not suprising really). However, you do have a number of options to choose from that will help you get this done.

Third-party tools
One option is to use a third-party commercial or free tool to package your Java application as an executable file.

Below are two tools that vary in both features and price, but there are several others on the Web also available for download.

• http://www.bysoft.se/sureshot/exej/
• http://www.duckware.com/jexepack/

Use a commercial installer.
InstallAnywhere is a commonly used installer which will manage the installation of your application and package your application for execution.

Use .jar
As an alternative, you may want to bundle your application as an executable .jar file instead of a .exe file. I won't go into the full details in this article but there is an excellent online tutorial here.

The essential thing you need to do is indicate which class within the .jar file is your application's entry point. For example, the bootstrap class for your application with a public static void main(String[] args) method. You can provide this information with the Main-Class header in the .jar manifest file. This header has the general form: Main-Class: classname ,where the value classname is the name of the class that is your application's entry point.

Use Java Webstart.
Java Webstart is one of the hidden gems of the standard Java runtime environment (JRE), and has been included with the JRE since version 1.3. It is a simple, but powerful and flexible way of deploying applications to any platform.

Webstart allows users of your application to launch and manage the application from their browser, e-mail or desktop. One of the key advantages of Java Webstart is that once the application is installed, everytime you start it, it will check to see if the user is running the latest version of the application. If not, the app will load and execute a new version over the network to the desktop and thus eradicates software currency issues.

This is particularly important if you have many users of your application. Importantly it also checks the local desktop environment of the user and will ensure that they have the appropriate version of the JRE installed to run your application.

Java Webstart is a series of articles in itself, so I would recommend that you visit the Java Webstart Web site for more documentation and tutorials.

Conclusion
The first two options will probably meet your needs for this question, but I highly recommend taking a close look at Java Webstart. It is part of the Java standard and works consistently on all platforms. It is my preferred approach to application packaging.

Michael Geisler is a solutions architect with Sun Microsystems and has more than 14 years of experience in the IT and telecommunications industry. He has been working with Java since the first public beta and is currently the vice-president of the Australian Java Users Group (AJUG).