Mr N

As you know I have been doing a lot of work with Java application containers and the like. I have recently been looking at Java Management Extensions. What is JMX?

JMX is a technology that lets you implement management interfaces for Java applications.

Copied that line from here, but the idea is that you write a java managed bean (MBeans) and register it with the JMX infrastructure. The JMX technology handles how people get at that information or service. The MBean can do several things like, peek at information, poke new values, initiate calls in the application or do notifications. There is a handy set of tutorials written by Sun to help you learn. I tried them but unfortunately I couldn’t get it to work. I compiled the java files exactly the way the instructions described, and when the instructions said launch jconsole and:

Select com.example.mbeans.Main from the list in the “New Connection” window, and click on “Connect".

My window did not have that class listed. Mine had the java process id only. When I used jps (java process list), it said:

668 – process information unavailable 2468 Jps

I eventually had to ask a question in Sun’s JMX forum and was pointed to the troubleshooting connection problems in jconsole, which although was not completely accurate it did point me in the direction of success. The problem comes from the the TMP environment variable. Under windows my environment variable was set to:

C:\tmp\jmx_examples\Essential>echo %TMP% C:\DOCUME~1\davidne\LOCALS~1\Temp

I know (cos I’m a Un*x bod) that tilde “~” is Un*x talk for your home directory. I think that my TMP variable’s “~” was being translated to:

C:\DOCUME\Documents and Settings\davidne1\davidne\LOCALS\Documents and Settings\davidne1\Temp

which does not exist! As a result jconsole and my JMX application could not communicate with each other and therefore could not make a connection. To fix the problem I changed the environment variable TMP to point to a real directory on an (NTFS partition (sorry another caveat)) without any funny characters in it:

set TMP=c:\tmp

Re-ran my mbeans application and all was well.

I recently signed up for the Spring Exchange in London. After filling in my credit card details I received my email confirmation to print out.

Your order from <my_payment_co> has been successful. The unique reference for this transaction is: 547230a90b70102cb146c7b63a005198 Please include this number in all correspondences.

While I’m prepared to admit that this number is unique, I think that it is some what out of place on an invoice. Can you imagine the conversation:

Me: Hello, there seems to be a problem with my course. Them: Do you have a reference number Me: Yes 547230a90….

There is a place of UUID’s, and that place is inside a computer system not (in my opinion) on invoices. This UUID number should map onto a more manageable invoice number.

Clearcase control yet. After a session of checkins I would ask my fellow developers to try and build to make sure I haven't missed anything - which can be a bit time consuming. Generally, I have missed adding a file. The reason for this is usually that the un-added files do not show on the Find Checkouts view.

Un-added files in Clearcase speak are called View Private files, that is, they are private to your view.

There isn't a tool which only finds View Private files, but the closest we can get is to View Private, Checked-out and Derived files. Issue the following cleartool command:

cleartool ls -recurse -view_only path\to\dir

or the short version:

cleartool ls -r -vie path\to\dir

You may want to use a command like grep to filter your results.

Under Windows some applications remember where a window was positioned when it was last used. Sometimes that position can no longer be on the visible screen. There are various reasons how this might happen.

1. Screen resolution is smaller than before.
2. Computer used to have 2 monitors, and now only has one.
3. Computer has 2 monitors which are now in a different order.
4. Program bug.

So, how do we move the window back into a position where we see the title bar. (Once we have the title bar in view, we can use the mouse to do anything we want.)

1. Open the title bar menu, by holding down alt + space.
2. Select Move, by pressing the ‘M’.
3. Use the arrow keys to move the window into a better position.
4. When you are happy with the new location, press Return to finish.
5. You can now use the mouse as usual.

Many thanks to Kevin for the first solution. Another solution is:

1. Open the title bar menu, by holding down alt + space.
2. Select Move, by pressing the ‘M’.
3. Press the down arrow key and then move the mouse. The title bar will snap to under the mouse, where ever it is on the screen.
4. Move the window to where ever you like and right click to drop it.

This blog is an addendum to Configuring Eclipse to use Tomcat and the Spring Framework but is solely related to Spring IDE 2.2.

1. Install Eclipse 3.4.1 JEE Ganymede SR1
2. Load Eclipse and goto Help->Software Updates…
3. Select the Available Software tab and click Add Site
4. In the Location enter http://dist.springframework.org/release/IDE then click Ok
5. After a bit of flickering Spring IDE Update Site appears (twice!) and along with a couple of others sites
6. If you right click on “http://download.eclipse.org/tools/mylyn/update/e3.4″, select Properties, Click Ok, then check and uncheck Include items that have already been installed then the “http://download.eclipse.org/tools/mylyn/update/e3.4″ site will change to Mylyn for Eclipse 3.4!
7. Check Mylyn for Eclipse 3.4, one of the Spring IDE Update Site and http://download.eclipse.org/tools/ajdt/33/update/, click Install… - If the Install button is not enabled then uncheck and re-check the buttons until they are select and Install is enabled!
8. You be taken to the Install screen, showing the size of the update as (40,518KB) and All details are ok. Click Next.
9. Now you have to agree the Licenses, so check I accept the terms of the license agreement and click Finish.
10. The software updater will start downloading and installing the updates. You can click the Details button to see what is going on.
11. You must then restart the workbench