Simply call pageContext.setAttribute() to export a variable from within a JSP custom tag: public class MyCustomVarTag extends TagSupport { ... The availability of the exported variable can be limited in the TLD: <tag> <name>setVar</name> <tag-class... The availability scopes are: Value Availability NESTED Between the start tag and the end tag. AT_BEGIN From the start tag until the scope of any enclosing tag. If there’s no enclosing tag, then to the end of the page. AT_END After the end tag until the scope of any enclosing tag. If there’s no enclosing tag, then to the end of the page.

When a certificate is "untrusted" by IE (such as a self-signed certificate), it displays a "Certificate error" icon next to the address bar. It used to be that you can click on that icon, "View certificates", then install it. On Windows 7, because of UAC , the "Install Certificate..." button is no longer displayed. In order to see the button, you have to start IE9 with administrator privileges: right click on the IE9 shortcut icon and select " Run as administrator... ". To save the certificate to a file, click the Details tab on the Certificate dialog, then click " Copy to File... ".

Oracle sqlplus command line tools does not support command line editing out-of-the-box. But on Linux there's a handy utility that enables command line editing with any command line tool: rlwrap - readline wrapper. Install rlwrap: $ sudo apt-get install rlwrap Create a keywords file .sql.dict (optional, but convenient): false null true access add as asc begin by chec... It would be nice to add the tables names also. Create an alias for sqlplus (put it in .bashrc ): alias sqlplus='rlwrap -f $HOME/.sql.dict sqlplus'

Maven is a powerful yet complex tool. When I started learning Maven, the first obstacle was, of course, its complexity. The second, was the lack of documentation that can get me off the ground quickly. This tutorial is an attempt to create a pragmatic guide that aims to get you familiar with Maven in the quickest way possible. The main theme is to get you on some hands on experience to start out and lead you through the creation of a simple Java EE project as quickly as possible. Instead of trying to give you a good read, I try to get you on the journey right away. The topics are roughly ordered by the logical sequence but you can jump around in any way...

The MIPS CPU is able to run both big-endian and little-endian. So a system built on MIPS can be either big-endian (mips) or little-endian (mipsel). The file command shows the architecture: $ file ls ls: ELF 32-bit LSB executable, MIPS, ... but readelf will tell the endianness: $ readelf -h ls ELF Header: Magic: 7f 45...

Unlike CVS, svn does not have a tag command, you create a new tag with copy : $ svn copy http://svn.example.com/repos/calc/trunk... The -r flag may be used to create a tag from an earlier revision: -r [--revision] ARG : ARG (some commands al...

Tomcat allows you to create multiple server instances for the same installation. The installation directory is identified as CATALINA_HOME , the instance directory is identified as CATALINA_BASE . Here are the steps: Create a base directory for the new instance, for example: /home/nogeek/tomcat1 . Create the subdirectories: mkdir -p /home/nogeek/tomcat/{bin,conf,logs,temp,w... Copy web.xml from the installation directory: cp $CATALINA_HOME/conf/web.xml /home/nogeek/tomcat... Copy logging.properties from the installation directory: cp $CATALINA_HOME/conf/logging.properties /home/no... Create server.xml under tomcat1/conf : <?xml version='1.0' encoding='utf-8'?> <Server ... Create script setenv.sh under tomcat1/bin : # Edit this file to set custom options # Tomcat... Copy startup.sh and shutdown.sh from the installation directory. Add the following two lines to the beginning of each: CATALINA_BASE=/home/nogeek/tomcat1 export CATAL... Create a soft link for catalina.sh in tomcat1/bin : $ ln -s ~/apache-tomcat-7.0.22/bin/catalina.sh cat...

Install usb.essentials . Package usbutils is optional. # opkg update # opkg install kmod-usb2 # opk... Install usb printer support: # opkg install kmod-usb-printer Install p910nd print server: # opkg install p910nd Edit /etc/config/p910nd : config p910nd option device /dev... Configure firewall to allow port 9100 ( /etc/config/firewall ): # Allow printer con... If clients are connecting from wan then the first line should be: option src wan Enable automatic start of print server when router boots: #/etc/init.d/p910nd enable Restart router: # reboot

This works for Tomcat. It may or may not work for other servlet containers. As far as I know it's not in the standards spec. In web.xml: <context-param> <param-name>env</param-name> ... If you start Tomcat without defining env , then #{initParam['env']} is ${env} . If you start Tomcat with -Denv=dev in JAVA_OPTS , then #{initParam['env']} is dev

Facelet requires strict XML syntax, so unmatched tags (start with no end, etc) generate errors. This is a trick to workaround that. The following code generates a row for every three items and for each row assigns a row id: <!-- using ui:repeat --> <ui:repeat var="name" ...