Detect Ctrl + A in a SWT listener

I knew there was a combination, but it took me about 10 minutes to find it.
Next time, it will go faster thanks to this post.

myWidget.addKeyListener( new KeyAdapter() {
	@Override
	public void keyPressed( KeyEvent e ) {

		if( e.keyCode == 'a'
				&& ( e.stateMask & SWT.MODIFIER_MASK ) == SWT.CTRL ) {
			// Do something
		}
	}
});

Using ActiveMQ with Petals ESB

Some of you may have already worked with the Petals JMS component.
This connector works in two different modes. In the first one, said provider, the component exposes services. When invoked, these services post messages on a JMS queue or topic. In the second mode, said consumer, Petals listens to JMS queues or topics and propagates JMS messages as Petals messages intended to Petals services.

The Petals JMS connector is not part of the Petals distribution, for the moment. You have to get the source code from our SVN and compile it yourself.
To put it in the distribution, it would need to support the new Petals logging mechanism. Besides, we have many upgrades to perform on this component. However, it works and can be used in some cases.

Here comes the point where I talk about interactions with ActiveMQ (AMQ).
AMQ is pretty nice and easy to use. I think we can say this is one of the key JMS products in the open-source field. However, there are some limitations to know when using it with Petals. And this is not due to Petals.

Petals and JMS servers can interact through the Petals JMS component. To work, this component needs a JNDI. More exactly, JMS queues and topics must be made available through a JNDI server, so that both Petals and AMQ can read and write in them. Unfortunately, AMQ does not provide a real JNDI implementation. This results in a strong limitation: you cannot work with Petals ESB, AMQ and static queues or topics.

There are 3 workarounds:

• Do not use AMQ’s JNDI implementation and use an external one.
• Use dynamic queues or topics. This is a specific mechanism of AMQ. Basically, it consists in choosing dynamicQueues/yourQueue or dynamicTopics/yourTopic as your JMS destination.
• Add a specific property in the JMS client (Petals JMS connector). Currently, the only solution is to patch the component. I have submitted a feature request to give more flexiblity in what we can pass to the initial context.

This information was also added to the documentation of the Petals JMS component.

Concatenate Files

It is sometimes useful or required to concatenate files.

One example could be log files, or files that have been split (as an example by a host like badongo, with *.aa, *.ab, *.ac… files).

Under Linux, this is feasible with the cat command.
For every file to concatenate, you only have to redirect the output of the cat command in the same file.

cat file1 > filename.ext
cat file2 >> filename.ext
cat file3 >> filename.ext

Under Windows, you can get the same result with the copy DOS command.

copy /B file1 + file2 + file3 filename.ext

At the end, filename.ext contains the concatenated content of the files file1, file2 and file3.