Ok, I recently wrote a program for my fathers company. I tested it on both of my computers, my dad's computer, and my mom's computer before he sent it out. He sent the beta version to his CEO, and 4 others. It worked just fine for the CEO and 3 others. However, one person got an error when he tried to open the program that said "The main startup class could not be found."
I know that this means it could not find the main class or method, I just don't know why. He said he installed the latest version of java and I provided the right download link when I distributed the program. How can I fix this problem?
There are a number of different factors that can cause this, but the most probable is that the computers don't have the appropriate Java Version.
My approach to solve this is to make the program in Java 5 standard. The very most part of the computers today should have at least JRE5.
As you are developing in NetBeans, try changing the compiling level of your project as described here
Related
I'm trying open this application: http://www1.icsi.berkeley.edu/~lucag/
(It's a research tool might might be great for my work so I really want to access it).
I'm running big sur on a 2014 mac book pro. It has Java 8 (I'm assuming that this is the 'Java Virtual Machine' which is specified in the instructions).
When I try and open the app I get the message:
"You do not have permission to open the application "ECGWorkbench'.
Contact your computer or network administrator for assistance."
I've tried everything on these two threads:
Can't run app because of permission in Big Sur
https://developer.apple.com/forums/thread/666611?page=3
I've tried opening the app on a mac which hadn't been upgraded to big sur. I can't get hold of a Windows or Linux computer.
I have two questions:
Is there a work around? I'm not a programer so bear with this question but if the app is written in Java and I had the code could I execute it? The folder with the app in had lots of other files. Or if I installed Linux in a virtual environment on my mac could I then open the Linux version of the app?
If it can't be fixed I'm going to try to contact the developers. The project doesn't seem to be very active so I'm not convinced they'd be interested in updating the app. If I could suggest what amendment they need to make or at least say why it's not working they might be more willing to help me out. Can anyone suggest what I could say to them? Something along the lines of 'I can't open the app because of XYZ, could you change the ABC' would be perfect. The NTL (neural theory of language) project created the app but they are part of the ICSI (international computer science institute) at berkley so I'm assuming they know what code is etc.
Thank you.
Rachel
I've been a little late with my reply, but I hope my solution will help you.
I had the same issue with eclipse (i need it for study things), so i opened my terminal and typed the following command...
codesign --force --deep --sign -/Application/Eclipse.app
After a reasign everything works fine for me.
I am having trouble installing the Android SDK on Windows 10. I am following a brazilian course on app development using react-native on android. This is a documentation page explaining how to create the development enviroment to do so: https://docs.rocketseat.dev/ambiente-react-native/android/windows (use google translate on the website to see the english version). However, on the part where they execute the following command :
$ C:\Android\Sdk\tools\bin\sdkmanager "platform-tools" "platforms;android-27" "build-tools;27.0.3"
the console returns:
Error: Could not find or load main class com.android.sdklib.tool.sdkmanager.SdkManagerCli
Caused by: java.lang.ClassNotFoundException: com.android.sdklib.tool.sdkmanager.SdkManagerCli
I have searched an entire day for a solution and discovered that, to my sorrowing dissapointment, this is a incredibly generic error when working with java in general. So I tried a plethra of things to no avail.
Reinstalling java(64-bit version)
Reinstalling jdk
Checking and rechecking what could possibly be wrong with the enviroment variables(I found no problems)
Searching through a dozen tutorials on how to install de Sdk via cmd.
Trying to get the Sdk on my machine through Android Studio(but couldnt use any of the Sdk commands necessary for the tutorial)
Some other stuff(I spent an entire day trying to fix this)
TLDR: I know this question has been posted in some form or regard before, I've read through all of them though, and none of them helped me.
If anyone has any idea of what I'm dealing with here, or has gone through this before, I would very much appreciate any advice that can be given. This problem has been drilling on me for a while now and I would really like to move on from it. I'm willing to provide any details on my current configuration but must of it you can find on the tutorial I linked earlier. Thank you for your attention.
It turns out there really are a billion reasons as to why this happens, and in my experience with stack, I don't think this will be answered anytime soon. So for future reference I will be giving some advice to anyone who ends up stumbling onto this problem.
Dual-boot your machine with Linux. I know this sounds like a non solution but it really is the only feasible solution. I spent an entire week trying to solve a problem that really wasn't worth solving. There are a ton of tutorials on how to do it. It took me less than 30 minutes to set up the whole thing and voilá, everything worked as a charm. Don't waste your time trying to make stuff like this work on Windows, especially since Java is involved.
The tutorial I used: https://docs.rocketseat.dev/dual-boot-windows-linux/introducao
PS: The tutorial is in Portuguese but Google Translate works pretty much perfectly on the page, so there should be no issues.
I have one program, I maintain, that was originally written in Oracle Forms 6i. A while ago I migrated it to 11g. Our users access this Oracle Forms program through their Internet Explorer browser on their Windows 7 machines.
The problem has been that the program only seems to run well for our users, when they have Java 6 Update 45, installed on their machines. Going to a newer version causes problems.
Today, I wanted to get this resolved, so I updated my PC to Java 8.31, and attempted to access my Oracle forms program using IE. (Thanks to Viewing oracle app and getting: java.lang.ClassNotFoundException: oracle.forms.engine.Main I was able to get the form running again in my web browser.)
When my form ran, I found the tab key wouldn't advance to the next field on the login dialogue box. But after I logged in the tab key worked. (The tab key initially not working is a small thing, but it has really annoyed some of our users.)
I then used several different forms. Some worked just fine, no problems. But then when I clicked a button, on one form, it would endlessly try to complete a request; to the point that I couldn't even close the web browser to stop it. (Finally I just used task manager to end my web browser’s process.) This seemed to go in line with what some of our users have reported: (when attempting to use the latest Java) that the Oracle forms application just stops working completely after a while.
Because of these issues our users want to keep Java 6 Update 45 on their machines. I know this is a major security hole, but I haven’t quite nailed down what the solution to it is.
Has anyone else had a similar issue? We're running Oracle Fusion Middleware 11; specifically Forms Services version 11.1.2.0.0
Thanks.
Well this may not be a question that needs answering after all.
I've done some more testing since asking this. Besides the login dialogue box (not responding, as it should, to the tab key) everything else works just as it should.
I still have one form that hangs; but that’s all (and it may be caused by something else). All my other forms seem to work just fine.
I talked with one of my co-workers, and I realized we really need to investigate and determine what version of Java our users really are using. They may not have used the most recent version of Java; which I used with success, today. Or some may be already on it; and that's why they aren't complaining.
At any rate more research, is needed on my part. Thanks to all who read this. If any of you have had similar experience in something like this, still feel welcome to answer/comment.
Currently i having an Assignment of AI(Artificial Intelligence) to develop an Expert System. We are using SWI-PROLOG as our practical class learning software, and now i am trying to apply e2glite to my Assignment.
I found that e2glite is able to download from www.expertise2go.com, and this website also providing the instruction and example. According to their instruction, computer must have Java(already installed).
So now i am trying to preview the sample that i had downloaded from the website, i am able to view the interface, once i click the "START The Consultation" is giving me "ERROR 800: MUST QUIT". In debug mode, it show me "Found on line 0 (below) before character 1 null"
According to the www.expertise2go.com, the meaning of error 800 is "Missing or Empty knowledge base". But i am follow exactly as the instruction to do it. I don't know where am i doing wrong.
P/S: i can view sample from the website, but no from my computer
Problem solved due to the java version is too updated.
Thus i downgrade the version from Java 7 Update 25 to Java 7 Update 13.
I'm currently developing a programm with Java to interact with an Arduino module. Now in Windows, it's running pretty well so far (I receive what I expect; I can work with the data), but in Linux (Ubuntu in my case); it's like the opposite. I installed Arduino and rxtx-java packages.
When I tried to use the Arduino program to connect to the Arduino board, I had to set a softlink on the ACM module to some serial or USB module. For example,
ln -s /dev/ttyACM0 /dev/ttyS99
Otherwise it won't even show up in the list in the Arduino program. So what I did then was starting the serial monitor tool (Ctrl + Shift + M) and sent it my start sequence waiting for an answer. It worked without a problem there (it was binary data so I couldn't verify if it was correct, but I got an answer at least).
The next thing I did was trying to do the same with my program, so the Arduino was connected to the PC, the softlink was set correctly, the device listed along with two normal COM-ports I have in my PC in my program, and I tried to connect, but it didn't work.
No error, no nothing, simply no answer of the board. After I waited a couple of minutes, it still didn't do anything, so I disconnected it from the PC, and then I got an array of zero-bytes as the answer.
What could cause this kind of problems and how would I fix it?
Thanks for your help
Volker
PS: the program is a jar file with all libraries/dependencies included
EDIT:
Hardware is an Arduino UNO Board Model R3,and on windows i'm using Arduino 1.0 to program it
Your symlink to /dev/ttyACM0 is double dubious:
Disconnecting+reconnecting or powering off+on might change the number of the dev.
ttyACM usually refers to modems, not to plain USB-serial converters like that used by Arduino (at least those with the FT232 chip). I would expect something like ttyUSB0. For those you also would not need a symlink.
If you installed from the Ubuntu packages you're bound to have problems. I tried this first myself only to find that there are serious issues. I would recommend downloading the most recent version of the IDE arduino-1.0-src.tar.gz.
You'll notice it's the source, I think you'll like it better that way. Or you can get the repository from Git, you'll find that information plus how to build the IDE in Building Arduino, Steps for First Time Setup. Besides the fact that the Ubuntu distribution version is buggy, it's also like old, big time.