How to distribute my Java program so that it is ru

问题:

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not package a JRE along with your program because it makes people have multiple different versions, some of which are outdated, and it causes security issues, but this is not a problem in this case since the computers that are going to run my application are not connected to the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?

回答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).

回答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.

---

..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.

回答3:

To make the problem run by double clicking it you can distribute it as a jar file or a batch file to call the jar file.
For the installation part you can make a batch file that checks if java is present and then call the installer if it isn't.
Edit:
The batch code:

IF DEFINED JAVA GOTO ok
java-installer.exe
GOTO end
:ok
your-application.jar
:end

回答4:

If you are finding it tough to implement the above mentioned methods. You can proceed with this simple approach.

Create a folder lib at a location. Place all the jars that your application uses into this. If you are able to create a jar for your application, you can very well place your application.jar into the lib folder too. Create a batch file at the same location that will contain the java command for your main class in it. The text within your batch might look something similiar to this :

set path="\lib\"
java -cp %path% package1.package2.MainClass

If you have any other dependencies, for ex: if you use images in your code under img/icon.jpg. Then you just have to shift the img folder to this location too.

Just zip these files using winrar and share it across. Running the batch file after extracting the zip would launch your java MainClass irrespective of the location in which it is placed in the client system.

PS : If you are unable to create a jar for your application and placing it in lib folder, just copy your bin folder with class files and paste it in the location and change the batch file accordingly to look for classes inside bin.