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Why Java Applet working only on my computer, but not on the others?

I just wonder something about java applet with awt. I quite disappointed with this problem and want to throw it away sometimes. Below are my descriptions:
I already created one application using java applet with awt controls on my own computer, let's say computerA using Window 7 32bit Operating System. To up and running this application, I update java version to the latest one.
Application is working fine with computerA. However, this application also need to run on the others as well. As my own situation, I run with another computer, let's say computerB using Window 7 64bits Operation System. I knew that the application created with 32bits java version, thus I decided to install this java version on computerB. However, when I run the application it can only display interface on browswer, but some of its function did not work.
Yet I didn't throw it away, I decided to configure in the last computer, let's say computerC. This computer use Window 8 32bits Operating System. I did configure as I did with computerA and computerB. The result is still exact as computerB.
I also checked up this solution on here, but it is not fit my problem.
Here are my questions:
What is the exact problem on here?
Where does the problem come from?
Is it solvable?
How can I solve this kind of problem? Any helps?
Update:
PostgreSQL Database also install in other local computers as well.
I noticed that If I convert my code into eclipse project, it worked fine. No problem at all.
Thanks in Advance.

How do I prevent a headless exception in Java?

I have an Applet and when I try to run it on my laptop, a headless exception is thrown by Java at the line where a JFrame is created. Now I know why the JFrame normally causes the exception but my computer was not in headless mode to begin with. I'm also still not sure what headless mode entails exactly.
I'm running Ubuntu and have a pretty recent version of java.
Also, I have successfully created JFrames and such in Eclipse when running Windows on my laptop (if that helps).

Have you tried setting java.awt.headless=true? I have done this once before on Solaris with no x-server in order to use the java.awt print libraries. It worked a treat. However it was more than five years ago and I don't have the source handy.
See Setting java.awt.headless=true programmatically
PS Are you on Ubuntu server or desktop? If the latter, I'd question why Java thinks you are headless.

Look # following link that might help:
http://www.theserverside.com/discussions/thread.tss?thread_id=52535

VLC dying when called from inside Java

I'm having a problem that, at this moment, I don't even know how to investigate properly. Any recommendations on how I can get more information are welcome and appreciated.
My company sells a product with a WinXP PC at its core. One of the product's tasks is being able to start a video player on demand -- VLC, in this case. (To be specific, VLC 0.8.6d; it's several years out of date, but upgrading is problematic for a few reasons.) The application responsible for starting the player and performing many, many other tasks is written in Java.
I have a test rig sitting next to my desk. It used to work just fine. But for some reason, it now gives a "Send Error Report" window when the Java app tries to start VLC: "VLC media player has encountered a problem and needs to close...." You know the one.
Clearly, I've done something that buggered things up. Problem is, I know neither what it could be nor how I would go about fixing it.
Stuff I know:
It's not a code bug. I run the same software on my development desktop machine, and it doesn't have this issue.
It's not the VLC install, nor is it a malformed video file. When I capture the command used to start it from Java and manually enter that command from a "cmd" window, it works fine.
It's not that sneaky bastich bug where Java punishes you if you don't manually drain STDERR and STDOUT when making a system call. I've got that covered.
I'm not getting any error messages or output when it fails; it just fails and gives me that pop-up window.
I'm stumped. Recommendations for either what it could be or how I can figure out what it is are very welcome.

Well, I’m not familiar with java and VLC, but I would do the following things:
Check that you have identical java virtual machines in both of your desktops. Just in case…
Check the process’s environment variables. They depend on parent process. Maybe VLC uses some of them.
Try to debug crashing with native debugger like WinDbg. Perhaps the call stack will give you more ideas.
Good luck!

My suggestions:
Create a simple java app that just launches VLC
Use your app to launch a simple command line windows program
Use your app to launch a complex program
Check to see if there is a memory constraint issue. Is VLC getting too little memory to run?
This really sounds like a memory/environment issue.

A number of things I would try
Make Sure both test and development machines are identical in every respect, the operating syste(if possible installed from same OS Disk), same JVM version, same memory allocation to JVM (you know those -X-ms stuffs). My fear is not with Java/JVM per se, it is with windows.
Make sure you can lunch for example Notepad from a Java app, and then something like Windows Media Player or MS Word.
Try and launch other versions of VLC to see if it is a VLC version problem.
Finally try and wipe the test box and re-install it(with Windows, you can never tell, a fresh installation might just do it!!)

The jar doesn't work properly... debugging post-build?

I'm in the dark as to how to even attack this particular problem and I have very little information to work with. Please bear with me.
My current project (a trading application) runs fine from Netbeans 6.9, and the build actually runs fine.. at first.. with `java -jar "my project.jar". It is a Swing application and everything comes up nicely. There are no error message in the terminal window.
However, when I engage the trading program itself (setting some of the threads into a more active state by clicking a command button), nothing happens. No error messages in the terminal, and none of the usual messages in the application. Like I said, it works fine from within Netbeans. Also, I've written other programs before using the same trading API (Interactive Brokers) and Swing, and haven't had this problem.
How do I even begin troubleshooting this problem?
I am admittedly build-stupid, meaning I have no idea how builds work and therefore no idea how to check if it is building properly.
I've checked /dist/lib and verified all of the libraries are present.
Thanks in advance for any suggestions.

Like Sean says, first check the JAR file to see if everything is there. Maybe the build is missing a file.
If that doesn't help, you can debug the application remotely. Here's a howto for Netbeans.

This happens because your Application is throwing an exception in the background. Try to execute your app using cmd:
java -jar yourappname.jar
You will see the exception in the cmd console, fix the exception and violá.
Best regards

Fake X11 display?

I have a Java program using AWT which I would like to run on a headless system. The display for the program does nothing other than display stats. When the program finishes, it exits. There is no user interaction on the display. The program creates an output file which I use in my build system.
Is there a way to get the Java program to run without an X11 display configured? Can I force Java to run the program without trying to display anything? I do not have access to the source code (it is just .jar file), so I can't make modifications to the source.
Any thoughts on how I could get this to work?

The underlying question here is how to run Java applications without an X server; providing a "fake" X server is only one option. In Java 1.4 and up, you can do the following:
java -Djava.awt.headless=true
This allows applications which use AWT to run on headless systems even without an X server.

Xvfb can do what you ask for. I've not used it myself, but here is a link to wikipedia: http://en.wikipedia.org/wiki/Xvfb

You can use a vncserver.
vncserver :1001
export DISPLAY=localhost:1001
java..
The added advantages is that you can actually view the gui
using vncserver 'just in case'

Could also run Xvnc in a low resolution and color depth.

As mentioned by Charles Duffy the traditional method is to tell Java to go headless.
Note that you can always mount the jar in Eclipse and use jad+jadclipse to see what it actually does, and perhaps even override a class if you need to by putting another class-file in "front" of it in the classpath.
A facility that might be relevant if the program uses Java2D is that newer Java versions use optimizations in the X11 server to render faster. This alone might be a reason to devote an X11 server attached to a high performance graphics card to your graphics processing.

I've used with great success in the past the PJA libraries, they don't seem to be maintained anymore, but then again, just just want to run...

I was able to get headless mode in OpenJFX with the command line arguments
-Dglass.platform=Monocle -Dmonocle.platform=Headless -Dprism.order=sw