BlueJ Problems

[Guest aliv25]

A member of staff in the IT department has come to me with the following problem.

 

When students and teahers open BlueJ, open a project and try to create an object on the object bench a

 

Terminal Window appears with the message "java.lang.ClassNotFoundException: Picture"

 

Followed by a pop-up message "An error occurred in a file for which the source cannot be found. class: source line number: java.net.URLClassLoader$1:199 ClassNotFoundException: Square (in java.net.URLClassLoader$1)

 

We have different BlueJ versions ranging from 1.3.5 to 2.1.3 Java version 1.4.2_04

 

When I log on as administrator BlueJ compiles fine. When I log in as a student I recieve the error messages.

 

I asked support from BlueJ and they think it could be permission rights as well as mismatch of Java versions on our machines.

 

Has anyone had any similar problems like this before or can reassure me that BlueJ support is correct?

[hayjo86]

It sounds like it might be missing some of the modules.

 

Try reinstalling the version of bluej or even check that u got the latest version of java.

 

Saying that i know that some of the old java coding will not compile in newer versions due to the new structure...i believe aliv25 u are aware of stuff like this like the collection creation (the angle brackets with the data type in)

 

Hope that is some help...

[Guest aliv25]

Well i'll probably get some assistance from my network manager as this is a task i am struggling to do on my own!

 

Re-installing the software is an option that may work just like "restarting the computer" does 90% of the time.

[hayjo86]

Are you trying to b funny by sayin it works like re-booting the pc 90% of the time?

 

U come on here asking for help, i gave u help and u being sarcastic.

[Guest aliv25]

Pipe down fella, dont want admin chucking you out after 2 posts!

[hayjo86]

Sorry i dint mean anything by it.

[Guest aliv25]

Hi all,

 

I have been snowed under recently (as you do working in network support) and the BlueJ problem i had last month has come to my attention again. Here is the problem...

 

I downloaded the latest version of Java (version 6, update 3), BlueJ (version 2.2.0) and uploaded the projects from the CD's Third Edition book.

 

I ran BlueJ opened the project 'club' in 'chapter 04)

 

All the classes compiled.

 

I created 3 objects on the object bench, and entered details in the required fields.

 

I called methods on each object and everything was fine. When I called an accessor method call it returned with the correct value / field. When I called a mutator method it changed an instance of an object.

 

The only problem was when i called the method to 'run a demo()', an error message appeared

 

'java.lang.IllegalMonitorStateException at java.lang.Object.notifyAll(Native Method)' (Screenshot attached to this message)

 

Basically, I think the problem is just a third away from solving. Has anyone had the same or similar problems?

[Guest aliv25]

Just an update, the teacher conducting the lessons has emailed me confirming that he has 9 students working on BlueJ :-)

 

I downloaded the latest versions of BlueJ and Java last week and restarted all the computers for updates to take place, which seems to have solved the problem! Anymore problems and no doubt messages will be posted on here, but for now fingers crossed all goes well!