Never done any JNI before, but recently had a need, and it turns out that it’s a whole lot more straightforward than I was anticipating. In my case, I needed to make some mods to an existing Win32 DLL, so YMMV. In a nutshell, the process goes like this: Define the methods you need as public native in your Java class. These guys are just stubs to the C calls you’ll be making down the [...]

I’ve been toying with building a simple Java spam filter for a while, and last night I actually got things off the ground. First things first, I need to get the stuff off the server, so I had a scout for some POP3 libs. Turns out there’s a few out there, but I figure that JavaMail from Sun has got to be worth a look (and I’ve got Elliotte Rusty Harold’s excellent “Java Network Programming” [...]

About a month ago, after years of faithful service, my Psion Revo Plus died. After looking for a suitable replacement, I ended up with a HP Ipaq 1940. Very cool little pda – ultralight/thin with bluetooth built in, and came with 128 Mb SD thrown in. Well, I never thought I would be able to live without an actual keyboard, but it definitely can be done. At first I used the on-screen keyboard, which was [...]

Have been wanting to investigate a decent charting component (for both Web and Swing use) for a while, but haven’t had the time. Did a bit of surfing, and I’ve just come across jFreeChart (http://www.jfree.org/jfreechart/) which looks just sensational. Tried out the demo app that ships with the product and it does a truly *amazing* number of charts, in a very tight amount of code. The dynamic charting stuff looks truly funky. Can’t wait to [...]

I’ve been using AquaFold’s cool little Java-based query tool – DataStudio (http://www.aquafold.com). Very neat. What I like about it: SQL Command Completion (including your own table/field names) Editable result sets 100% Java – so use it on your platform of choice Free for personal/educational use Worth a look. Just drop in your own JDBC driver and you’re good to go. I’ve tested against mySQL and Sybase and it works a treat.

If the limitations of InetAddress get you down, you can go the whole hog and interrogate your DNS Zone! Ever wanted to find out the MX record for a given domain programmatically? Now you can! Came across this groovy little “dnsjava” library while looking into java mail servers. Download the source from http://www.dnsjava.org/ Even comes with a port of dig written in Java… This guy is very sharp!

Have had to add some SNMP capabilities to an app recently (basically the ability to generate traps when bad things happen), so I’ve done a bit of scouring for available libs on the net. I originally looked at SNMP adaptors for JMX, but haven’t found any open source ones out there. (Anyone?) Of the three or four SNMP libs that I looked at, I settled on Jon Sevy’s package at: http://edge.mcs.drexel.edu/GICL/people/sevy/snmp/snmp.html What I like about [...]

Ever wanted to catch O/S Interrupts in your Java code? Things like CTRL-C on Windows or various SIGs on your fave brand of Unix. Well it turns out you can! A friend from work tipped me off to a feature introduced in JDK 1.3 where you can call Runtime.addShutdownHook(Thread yourHook). You pass in the thread unstarted, and when the VM gets a shutdown signal, it’ll start your thread. Runtime rt = Runtime.getRuntime(); rt.addShutdownHook(new Thread() { [...]

It’s been way too long since I’ve blogged regularly. But I’ve now got MT up and running, life is good again. Now I just need to track down some cool MT templates. Watch this space.