Accessing Excel with Java

Excel is Microsoft. Java is not. Nevertheless there are ways to manipulate the XLS-format from Java.

Some Open Source solutions are listed here:

„Handle Excel files“ by Réal Gagnon

I tested two of them:

1. JXL
2. POI

Jxl is straightforward and easy to use. POI is for all kind of Mircosoft formats, not only for Excel. IMHO it is a little more tricky to use.

Coding by Convention with Grails

Not so long ago the 0.3-Version of grails was released. A good reason for me to check what this coding-by-convention is all about.

An it seem to be all great! The opposite is the application i am working with. And with our app all came up with good intentions for the following reasons:

• being flexible: The cutomers/users dont have to decide what they want or what they need, we can configure this later…
• being different: the different companies dont want to adjust their internal workflows and they dont have to. we can configure all the differences

This is becoming more and more configuration with every new implemented feature. In the end your are not a developer any more, your are a configurer. –> Configuration Hell!

Coding-by-convention must be precise. You must exactly know whats best, what you need or how to name something. No more maybies.

Ressources for grails:

• www.grail.org
• Sven Haiges blog

My mule impression

This week I run into Mule. This is an open source ESB (Enterprise Service Bus) and is all about integration. In one article it is described as a kind of Leatherman of integration tools.

Here the best examples I have found so far:

• A File Sucker-Example, monitoring a directory for files to import. This is based one Spring and Mule.
• A Snowdude-Example why an ESB is useful

Another ESB open source implementation is part of the JBoss tool collection. Is a comparison out there?

Misc Java Notes

• Intelligent WEB-GUI-Components (kind of Ajax):
  • example one
  • example two
• New eclipse version: What’s new in Eclipse 3.2?
• Java-classpath-configuring in Windows: with the following two Batch-Files it is possible to add all the files of a directory to the classpath. (Copied from here)

  build.bat
  ---------
  set CP=
  
  for %%i in (lib*.jar) do call cp.bat %%i

  cp.bat
  ------
  set CP=%CP%;%1

• how to let tomcat destroy a session. Two options: in the web.xml-configuration or in ur application.

Free Download of JavaOne Sessions (2005,2006)

Here you can find all the JavaOne Session of 2005 and 2006. The PPT-PDFs (or maybe star-office slides) are downloadable directly, for the Multimedia-Version you have to register.

Web Framework Comparison

Last week I had a discussion about the future of Client Technology (web vs. rcp). For web technology it is really hard to decide which underlying web framework to use. So here is the best comparison i have seen so far.

Updating eclipse with callisto

I just tested the eclipse callisto release. The purpose of this project is to get the 10 main eclipse projects together in one simultaneous release. This should increase the usability and facilitate the working with this different projects in just one eclipse distribution.

It is as easy as using the callisto update site with the eclipse update manager. The new remote update site for callisto is:

http://download.eclipse.org/callisto/releases/

After connecting to this server, you can install the features you need. If the selected feature requires another feature, the required project can be added using the 'Select Required'-Button.

I can say more in a little while (testing while working with it). All in all the first impression is really good. Right know I have different eclipse distributions installed on one system. One for each top level project. Hopefully we dont need that anymore in the future…

Wait a second

Thread.sleep(1000);

DateFormat and current date

My example in one ugly line:

DateFormat.getDateInstance(DateFormat.MEDIUM, Locale.GERMAN).format(new Date())

Result is:

24.03.2006

Setting the time a Tooltip is displayed

In Java-Swing you can set a Tooltip for any kind of GUI-Element extending JComponent using the Method setToolTipText. But how to set the Time this tooltip is display, when the mouse-cursor is still. This is how to set the time a Tooltip is displayed, in this case for the Swing-Component myTable to 12000 milliseconds.

ToolTipManager.sharedInstance().setDismissDelay(12000);
ToolTipManager.sharedInstance().registerComponent(myTable);