How to distribute my Java program so that it is runnable by double-clicking a single file?

Question

I have a Java rich client desktop app. that I want to distribute on some computers at work, but I've never done something like this before. People aren't too computer-savy at my workplace and since it is a student job, I won't be there for much longer and I'd like it if I could make my program easy to run by making it runnable when people double-click on it.

I also don't want to have to manually install a JRE to have it run. Basically, what I'd like to know is how to make my java application runnable easily by double-clicking (even if it's only on windows, it's okay). I'm pretty sure I'm going to need to package the correct JRE version alongside, but I don't know what's the correct way of doing this.

I read on some sites that you should not package a JRE along with your program because it makes people have multiple different versions, some of which are outdated, and it causes security issues, but this is not a problem in this case since the computers that are going to run my application are not connected to the internet and are only used to run this program anyway.

Somewhat related question: Since my application is currently an Eclipse project, I get my resources such as icons, images, SQLite database (for read and write), etc. using relative paths (e.g.: img/test.png).

Am I going to have to change any of those paths to have them keep working even while packaged?

Answer 1

What you're looking for is a JAR file. In eclipse, it's quite easy to make a Jar file. Specifically, you'll want to right click on your project, go to Export, and then select "Runnable Jar." Be careful with paths to folders. You may need to keep a resources folder next to the Jar file. You may need to provide some more specifics to get an exact answer on that. Typically, a Resources folder is located in the same spot as the JAR file (in the same folder on your computer).

Answer 2

A better option for easy install of a Java app. with a GUI is to launch it using Java Web Start. For the user, JWS is the 'one click' installation option that can (install & launch the app. then) add desktop shortcuts and menu items. A JWS launch would mean some more work for you, but it is a breeze for the end user.

To ensure a suitable JRE is present to run the app., use deployJava.js (see the JWS link for more details). The script would need to be reconfigured to get the JRE installer from your local network - the default is to get it from Oracle.

Most of the resources should be packaged in Jar files and supplied along with the app., but for the DB, use the JNLP ExtensionInstallerService to call the DB installer.

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..Java Web Start is kind of a link (or I can make it a shortcut on the desktop) that the users will click to either install the JRE and run the program if the JRE isn't installed, or just run the program if the JRE is present on the computer.

The way it would work is to have a web page on the local intranet. When the user visits the page, the script checks for a suitable JRE.

• If it is present, it writes the link to the launch file.
• If there is no JRE, or the version is too low, it will guide the user through installing it (just a matter of them clicking 'OK' when prompted). Then it will put the link to the app.

I can then configure the link to grab the JRE from the server on our network.

That's the part where you need to reconfigure the script. AFAIR the script exposes an URL at which to look for JREs - that can be changed to point to a place on the intranet.

..So "Web" is only just in the name, the computers don't have to be connected to the internet to have this work, right?

Yes. JWS is a great launch technology for Java rich clients, but is a poorly chosen name.