When using JavaServer Pages, you want to use JSTL to be able to to flow-control (iterations and conditionals) in a reasonable way. And the recommended way to use JSTL is to use the Expression Language (EL). However, using EL is not a good idea at all. Contrary to Java and plain JSP, EL lacks static typing. This means that many errors which the compiler can catch is not detected until runtime when using EL.

It’s quite annoying that you cannot use wildcards in the -classpath command line option to java and javac. Quite often you want to include all .jar files in one directory. Here is a way to get that effect: java -classpath `echo lib/*.jar | sed -e “s/ /:/g”` org.foo.MyApp You can even include all .jar files in a whole hierarchy of directories: java -classpath `find repository -name *.jar -printf %p:` org.foo.MyApp

After installing Ubuntu 8.04 (hardy) desktop, there are some things you might want to change. This article focus on user configuration (mostly editing dot files in your home directory) and do not require superuser access. Some of this changes requires that you log out to take effect. Customize the bash shell By default, bash save all commands in a history file. This can be quite annoying when you run several instances of the shell in parallel, and may also be a security concern.

Create a file /etc/ppp/peers/name: pty "pptp host --nolaunchpppd" name username remotename PPTP require-mppe-128 file /etc/ppp/options.pptp ipparam name Add this line to the file /etc/ppp/chap-secrets: username PPTP password * Create a file /etc/ppp/ip-up.d/tunnel #!/bin/sh if [ "${PPP_IPPARAM}" = "name" ]; then route add -net RemoteNetworkWithNetmask dev ${PPP_IFACE} fi RemoteNetworkWithNetmask is the network on the remote side you want to access via the VPN tunnel, e.g. 172.16.0.0/12. Connect by running sudo pon name

After installing Ubuntu 8.04 (hardy) desktop, there are some things you might want to change. This article focus on system configuration (mostly editing in /etc) and requires superuser access (using sudo). Some of this changes requires reboot to take effect. Fix terminal font rendering bug There is a bug which gives bad font rendering in the terminal window. Fix it by doing this in a terminal: cd /etc/fonts/cond.d sudo unlink 10-hinting-medium.

GNU Screen has support for scrollback, but by default you have to use awkward keys to use it. I would like to be able to use Shift-PageUp, Shift-PageDown and the mousewheel to scroll, just like you can do in xterm. It was not easy to configure Screen for this, and it involves cooperation with the terminal emulator. But I finally managed to achieve a solution which works pretty well. Add this to your ~/.

GNU Screen allows you to open several sub-windows within one terminal window. By default, you switch between them using Ctrl-A followed by n or p. I think this is a bit clumsy, I would like to switch with Ctrl-Tab and Ctrl-Shift-Tab just like you switch tabs in Firefox and many other applications. The sub-windows in Screen is conceptually just like tabs in Firefox, so it’s logical to use the same keys to switch between them.

When you deploy a web application in a JavaEE application server, it usually consist of a .war archive. Sometimes, the web application needs some configuration parameters. The most common way to do this is to have <context-param> in web.xml. That is simple and works fine except that the web.xml file needs to be inside the .war archive. This makes it inconvenient to change a configuration parameter since you have to repack the .

When you install Ubuntu 8.04 (hardy) desktop, you get a lot of packages installed by default. Most users will never use many of these packages, so you end up with a lot of unnecessary packages. Most of these packages are harmless and only waste disk space when not used. However, some packages can actually affect the system in a negative way, such as draining resources (other then disk space), and you should consider removing them if you not actively use them.

(This post has been edited since it was first published.) I wondered why you usually mount / (the root file system) read-write in Linux and decided to do some experiments to find out if it is possible to have it mounted read-only. So why do you want to do that? Perhaps you have the root file system on a read-only media, such as CD-ROM. Or on a writable media which can only handle a limited number of writes, such as a CD-RW or flash disk.