The only thing that I still couldn’t figure out was how to change the color of the folding/breakpoint bar next to the gutter. And I’m really starting to like the Monaco font that seems to be the default programmer’s font on Macs (I found a Windows version of Monaco but haven’t tried it).

I guess TextMate envy still exists even when you are on a Mac with a registered version of TextMate heh.

Here’s my Eclipse preferences (I just did a File -> Export -> Preferences). It seems Eclipse only allows a full export/import so you may want to be careful to backup your existing preferences before importing mine.

First, my (extremely talented) colleague makes a similar copy and paste blooper, and one day later I repeat the same mistake. But, but… Select boring code, Ctrl-C, Ctrl-V, it’s sooo easy…

I think the chances would be higher if instead of an applet, a Java Web Start application was used instead. Bundling the JMF libraries could work, but there hasn’t been any report of success as far as I can find. (It is possible with a full-blown Java application though.)

Any leads at all would be good. In the meantime I will be trying this out myself.

Firstly, the .NET question: does anybody know how to get this Button ListBar Control to work?

I was trying to get the.NET Button ListBar control into my VB project’s toolbox – I followed these instructions:

To use the control, add either the ButtonListBar.vb or ButtonListBar.cs file to your project. You should find the control automatically appears in the Toolbox; if not you’ll need to force the toolbox to display the
control: typically I find that double clicking on the control source file to open its designer causes this to occur.”

Unfortunately, it doesn’t appear automatically when I added ButtonListBar.vb (via “Add existing item”). So I double-clicked the source file… But it threw out this error

The class ButtonListBar can be designed, but is not the first class in the file. Visual Studio requires that designers use the first class in the file…

Which I don’t understand of course. Neither did it cause the ListBar control to appear in the Toolbox. I have emailed the author about this, but if anyone knows what I’m doing wrong, please let me know ASAP.

This of course leads to the question: What is the correct way to add a user control which comes in source form?

Now, for the Java question: is there an existing library/package that would allow me to calculate the median and, say, the 95th percentile of a population quickly? I searched to no avail, of course, before I ask this.

I can do this myself the hard way, but I’m really pressed for time. I’d like to reuse an existing solution if there is any.

Thanks for any leads!

SitePoint is popularly-known as one of THE places for PHP articles (its PHP forum is also one of the busiest) – this shift in focus to enterprise technologies is encouraging, since I’ve always thought newer web developers tend to view PHP as the end all and be all to getting a serious job in web development. This is my opinion of course, and in no way should this be construed as trolling! :-)

Are you a Java developer? Come help make the Java forum (it’s currently called the “Java, ColdFusion and Other Languages” forum, but that will soon change in our proposed forum structure changes) more lively. We need more members to help grow the Java forum, be they leaders in discussions or fledging newbies.

A programmer can be significantly more productive in Python than in Java.

in his article “Python & Java: a Side-by-Side Comparison“. The basis of his argument centres around dynamic typing in Python, among other things like code verbosity.

My favorite though is the enhanced for loop which is similar to the foreach construct in languages like PHP and Python.

The following example reads “for each Object in the Collection C…”:


void displayAll(Collection c) {
for (Object o : c)
((String)o).display();
}


I’ve always found the Java (and C/C++) for-loop idiom to be overly wordy and reduces code legibility, so this is a welcome addition.

Related links:
Previous interview with Joshua Bloch

Basically, it would be a “port” of BlueJADE (which works for JBoss) for WLS. Now if only I could figure out from the BEA documentation how to add a managed service, but the JMX edocs were of no help – lots on how to manage MBeans, nothing on how to actually deploy one for a new service.

It appears that WLS’s and JBoss’s JMX implementations are quite disimilar enough that there isn’t any resemblance in their XML descriptors nor their directory structures – I’m lost on how to proceed. And looking at how JBoss manages all it’s services via JMX, with configuration descriptors (*-service.xml files) clearly visible in the server directory, I can really see how JBoss’s microkernel architecture really pays off in this respect. I didn’t even need documentation to figure out how it works in JBoss!

I’ve signed up on the Open Source forums (only 3 of us at the time of writing).

Please do contact me at redemption at codefront.net should you be interested. This is (what I foresee) a good opportunity to share your experience and expertise with the Java community via the informal weblog medium.

UPDATE: I’ve setup a subdomain at http://javatips.codefront.net/.

I apologize to java.bloggers for being lead to my old entry yet again.

I may yet have to re-add by blog unless this fixes itself soon. (It’s an unresolved issue.)

EDIT: It appears that an update of my blog details fixed the problem.

Providing a static factory method instead of a public constructor has both advantages and disadvantages, which will be discussed at length in the rest of this entry.

Static factory methods have names
A class can have only a single constructor with a given signature, which is a restriction in cases where a class needs to be able to be instantiated using identical parameter lists. In cases like this, you can replace constructors with static factory methods with more intuitive names that highlight their differences.

Static factory methods can improve performance
This is because static factory methods do not have to actually instantiate new objects each time they are invoked. This is what allows for the Singleton pattern, where a single instance is returned. It also allows instances to be cached within the object in cases where object instantiation is expensive (like for the case of instantiation of fields from a database) or frequently done.

Static factory methods can return a subtype of their return type
This allows for interfaces to be returned by static factory methods, which is best exemplified in the Collections Framework. Needless to say, forcing a client to refer to the returned object by its interface rather than its actual class is a good practice.

Also, the class of the object returned can be private (non-public), so there is a degree of encapsulation where the private class can be modified without impacting clients of the API (possibly for bug-fixing or improvements, or just plain maintainence). The private classes can also vary depending on the parameters to the static factory, so long as they are subtypes of the return type, allowing for greater flexibility.

Classes without public or protected constructors cannot be subclassed
This is an unavoidable fact, so classes designed for inheritance must have at least 1 public constructor to be able to be subclassed.

The verdict? Use static factory methods for a more intuitive API, to improve performance via object-caching, to implement singletons, in interface-based frameworks, and to return objects of private classes. Use constructors in classes designed for inheritance (there shouldn’t be many of these) and for greater visibility in API documentation (since they appear in a separate table in standard Javadocs).

What is BlueJADE?

BlueJADE makes the JADE agent system a manageable service under a J2EE application server. BlueJADE allows JADE to become a service that can be managed through JMX (Java Management Extension).

Installation in WinXP

Setting up the environment
- Install JADE, BlueJADE and JBoss. It is recommended that a version of JBoss with Tomcat already integrated be used. Refer to their respective documentation on the installation process. This often involves simply unarchiving the binaries, or compilation if you’re building from sources.
- Set the JADE_HOME, BLUEJADE_HOME and JBOSS_HOME environment variables to point to the respective directories.

Group Installation
- Pick a group under $BLUEJADE_HOME/groups to install. It’s simplest to choose the ‘simpleagent’ group.
- To install the group, run the install script (install.bat) in $BLUEJADE_HOME/groups/simpleagent. 1 argument, the group to install, should be specified. A 2nd argument would copy over an existing JBoss environment if specified.
Eg.
$ install simpleagent default
- At this point, you could run into problems. Apparently, the environment variables are not picked up properly by the installation script/program so you have to edit $BLUEJADE_HOME/bin/win/install.properties to add in the “missing” environment variables.
The variables include:
LOCALHOSTNAME, GROUP, TEMP, JBOSS_HOME, JADE_HOME, BLUEJADE_HOME
Set these to point to the exact path/name.
- If installation goes well (no error messages), open the file $JBOSS_HOME/server/simpleagent/deploy/jade-service.xml. The element with name=”ConfigDocName” should be pointing to an incorrect path – change it to point to $JBOSS_HOME/server/simpleagent/conf/jade-service-config.xml. Depending on the group you’re installing, there could be more bogus paths – just keep an eye out for them and correct accordingly.
- Open that jade-service-config.xml file and make similar corrections for the 2 (or more, depending on your group) paths there:
xsi:noNamespaceSchemaLocation=$JBOSS_HOME/server/simpleagent/conf/JADE-1_0.xsd
jadeArgs=$JBOSS_HOME/server/simpleagent/conf/jadeboot.properties

Running JBoss with JADE container
- Run JBoss with the simpleagent environment by executing the following command at $JBOSS_HOME/bin
run -c simpleagent
- If all goes well, you should see no errors in the startup process and a JADE Remote Agent Management GUI appears (only for simpleagent and demoagent groups).
- JADE is now manageable as a service under JMX – go to http://localhost:8080/jmx-console/