Problems with installing Oracle DB 12c EE, ORA-12547: TNS: lost contact

For development purposes I wanted to install Oracle Database 12c Enterprise Edition to Vagrant box so that I could play with it. It should’ve gone quite straight forwardly but in my case things got complicated although I had Oracle Linux and the pre-requirements fulfilled. Everything went fine until it was time to run the DBCA and create the database.

The DBCA gave “ORA-12547: TNS: lost contact” error which is quite common. Google gave me couple of resources to debug the issue. Oracle DBA Blog explained common issues which cause ORA-12547 and solutions to fix it.

One of the suggested solutions was to check to ensure that the following two files are not 0 bytes:

ls -lt $ORACLE_HOME/bin/oracle
ls -lt $ORACLE_HOME/rdbms/lib/config.o

And true, my oracle binary was 0 bytes

-rwsr-s--x 1 oracle oinstall 0 Jul  7  2014 /u01/app/oracle/product/12.1.0/dbhome_1/bin/oracle

To fix the binary you need to relink it and to do that rename the following file:

$ cd $ORACLE_HOME/rdbms/lib
$ mv config.o config.o.bad

Then, shutdown the database and listener and then “relink all”

$ relink all

If just things were that easy. Unfortunately relinking ended on error:

[oracle@oradb12c lib]$ relink all
/u01/app/oracle/product/12.1.0/dbhome_1/bin/relink: line 168: 13794 Segmentation fault      $ORACLE_HOME/perl/bin/perl $ORACLE_HOME/install/modmakedeps.pl $ORACLE_HOME $ORACLE_HOME/inventory/make/makeorder.xml > $CURR_MAKEORDER
writing relink log to: /u01/app/oracle/product/12.1.0/dbhome_1/install/relink.log

After googling some more I found similar problem and solution: Relink the executables by running make install.

cd $ORACLE_HOME/rdbms/lib
make -f ins_rdbms.mk install
 
cd $ORACLE_HOME/network/lib
make -f ins_net_server.mk install
</re>
 
If needed you can also relink other executables:
<pre lang="shell">
make -kf ins_sqlplus.mk install (in $ORACLE_HOME/sqlplus/lib)
make -kf ins_reports60w.mk install (on CCMgr server)
make -kf ins_forms60w.install (on Forms/Web server)

But of course it didn’t work out of the box and failed to error:

/bin/ld: cannot find -ljavavm12
collect2: error: ld returned 1 exit status
make: *** [/u01/app/oracle/product/12.1.0/dbhome_1/rdbms/lib/oracle] Error 1

The solution is to copy the libjavavm12.a to under $ORACLE_HOME lib as explained:

cp $ORACLE_HOME/javavm/jdk/jdk6/lib/libjavavm12.a $ORACLE_HOME/lib/

Run the make install commands from above again and you should’ve working oracle binary:

-rwsr-s--x 1 oracle oinstall 323649826 Feb 17 16:27 /u01/app/oracle/product/12.1.0/dbhome_1/bin/oracle

After this I ran the relink again which worked and also the install of the database worked fine.

cd $ORACLE_HOME/bin
relink all

Start the listener:

lsnrctl start LISTENER

Create the database:

dbca -silent -responseFile $ORACLE_BASE/installation/dbca.rsp

The problems I encountered while installing Oracle Database 12c Enterprise Edition to Oracle Linux 7 although in Vagrant and with Ansible were surprising as you would think that on certified platform it should just work. If I would’ve been using CentOS or Ubuntu it would’ve been totally different issue.

You can see the Ansible tasks I did to get Oracle DB 12c EE installed on Oracle Linux 7 in my vagrant-experiments GitHub repo.

Oracle DB 12c EE Ansible Tasks
Oracle DB 12c EE Ansible Tasks

Creating Vagrant Base Box with Veewee

Vagrant is a great tool for creating and configuring lightweight, reproducible, portable virtual machine environments but the first step for using Vagrant, downloading an existing “base box”, raises some questions. E.g. How are these unverified boxes built? So, you might end up building your own base box which is often time consuming and cumbersome. Fortunately there’s a tool called Veewee which aims to automate all the steps for building base boxes and to collect best practices in a transparent way.

Vagrant Base Box with Veewee

Veewee is a tool for easily (and repeatedly) building custom Vagrant base boxes, KVMs, and virtual machine images. You can use it to build a Vagrant box in Linux, Mac OS X and Windows but I found out that fulfilling the requirements on Windows is quite difficult (read Ruby and RVM) so just forget it.

To get you started there are some requirements you need to fulfill. First you’ll need to install at least one of the supported virtual machine providers like VirtualBox and second you need some development libraries.

On Ubuntu 15.04 Linux and using VirtualBox you need these packages:

$ apt-get install virtualbox git curl ruby ruby-dev libxslt1-dev libxml2-dev zlib1g-dev

Install RVM on Linux

For Ruby environment it’s recommended to use either rvm or rbenv. I chose the RVM and followed the RVM install documentation.

Install mpapis public key:

$ gpg --keyserver hkp://keys.gnupg.net --recv-keys 409B6B1796C275462A1703113804BB82D39DC0E3

if keyserver fails, you can use $ curl -sSL https://rvm.io/mpapis.asc | gpg --import -

Install RVM stable with ruby:

$ \curl -sSL https://get.rvm.io | bash -s stable --ruby

Installing Veewee with RVM

With RVM already installed, ensure a ruby version that’s supported by Veewee is available on your machine:

$ source /home/marko/.rvm/scripts/rvm
$ rvm install ruby

Clone the veewee project from source:

$ cd <path_to_workspace>
$ git clone https://github.com/jedi4ever/veewee.git
$ cd veewee

Set the local gemset and ruby version within the current directory:

$ rvm use ruby@veewee --create

Run bundle install to install Gemfile dependencies for your local gemset:

$ gem install bundler
$ bundle install

Bundle install will take some time.

Building Vagrant Box with Veewee

Veewee uses definitions to build new virtual machines and ‘definition’ is derived from a ‘template’ and preconfigured templates are found in templates/ folder. Veewee Basics explains how you can create your own customized definition.

For my customized Vagrant Box I decided to use Tommy Muehle’s definition as a template as it contained what I wanted. Simple CentOS 6.6. Box with Puppet. I just changed the localization to Finland and made it bigger for WebLogic use case in mind. My definition for Vagrant Box can be found in GitHub.

To use my definition just clone the repository for CentOS 6.6 Box, copy the “centos-6.6-x86_64_puppet” folder to definitions/ folder under Veewee and make your own changes if needed. After you’re done run:

$ bundle exec veewee vbox build centos-6.6-x86_64_puppet

The build command runs Veewee scripts and automates the manual steps needed while installing a new Linux distribution.

Installing CentOS to Vagrant Box with Veewee

To export the Box for further use with Vagrant, run:

$ bundle exec veewee vbox export centos-6.6-x86_64_puppet

The above command is actually calling “vagrant package –base ‘centos-6.6-x86_64_puppet’ –output ‘boxes/centos-6.6-x86_64_puppet'”. The machine gets shut down, exported and will be packed in a centos-6.6-x86_64_puppet.box file inside the current directory.

And you’re all done. Now you can use your just created base box for Vagrant boxes. Import it into Vagrant’s box repository and use it to initialize a fresh project:

$ vagrant box add 'centos-6.6-x86_64_puppet' 'centos-6.6-x86_64_puppet.box'
$ vagrant init 'centos-6.6-x86_64_puppet'

Using Veewee to build a Vagrant Box is simple and what’s more important it’s automated and reproducible. Using Ruby and RVM on Windows 7 turned out to be practically impossible but old ThinkPad W510 with Ubuntu 15.04 worked nicely. Of course you could create a base box with Vagrant way which means installing and configuring your Linux manually. But why would you want to that if you can just automate it?

Disabling Derby in Oracle WebLogic 12c

Oracle WebLogic has some interesting traits to help developers frustrate. From Weblogic 10.3.4 and above the Apache Derby Database is included in the installation. That’s fine but from 12.1.2 release it also starts automatically which is usually unwanted, useless and waste of resources. Previous versions of WebLogic didn’t automatically start the Derby database.

Fortunately you can disable it as basically there is a simple IF statement in the “$WL_DOMAIN_HOME$\bin\setDomainEnv.cmd” file:

@REM Set DERBY_FLAG, if derby is available.
 
if exist %WL_HOME%\common\derby\lib\derby.jar (
    set DERBY_FLAG=true
)

If you want to prevent Derby form starting you have three options:

  • Rename “derby.jar” to something else
  • Delete the IF statement from start-up script
  • Set the DERBY_FLAG to false in the startWeblogic.cmd script

I couldn’t find Oracle’s documentation about Derby in Weblogic but those four options seems to work. I prefer the third option which is quite easy to configure. (via Oracle Community)

In my “$WL_DOMAIN_HOME$\bin\startWebLogic.cmd” I added

...
@REM Call setDomainEnv here.
 
@REM Disabling Derby
set DERBY_FLAG = false
...

Connecting Jabra HALO2 Bluetooth Headset with Windows 7

Recently I got Jabra HALO2 Bluetooth headset for teleconferences but had problems to get it work with Windows 7 and Dell Latitude E6530. Windows found the device and wanted to install drivers but couldn’t find any. The solution was easy: update your laptops’ Bluetooth drivers. I downloaded Dell Wireless 380 Bluetooth Application version 6.5.1.4000,A02 from Dell’s drivers page and got it working.

Jabra HALO2 is a wireless Bluetooth headset with dual microphone for noise filtering and can be paired with 2 Bluetooth-enabled devices. It can be also used with USB cable and 3,5mm cord and can control music player and sound volume. The battery last for 8 hours talk or music and 13 days on standby.

The wireless headset works with e.g. Windows 7 but some laptops like my Dell Latitude E6530 needs specific manufacturer’s Bluetooth drivers before Windows starts to play nice with them. At first I got the “Bluetooth peripheral device driver not found” error when trying to connect a Bluetooth device and as the Jabra HALO2 headset doesn’t need drivers it was time to look for them from Dell’s support.

Dell’s drivers page doesn’t have Bluetooth drivers directly so I figured to get the “Dell Wireless 380 Bluetooth Application” version 6.5.1.4000,A02 (31/10/2013) which provides an application for DW380 Bluetooth. After installing the 245 MB package Windows started to install the missing drivers and the Bluetooth headset’s hardware functions got found: AV, Hands-free, Headset and Remote Control. I can’t say that updating the drivers will help everyone but what I searched about this issue it was the solution which got these and other Bluetooth headphones working with different laptops.

The start with my new headset wasn’t the easiest but after I got it working the Jabra HALO2 Bluetooth headset works nicely and is pleasant to use for teleconferences with Lync and with my Lumia 800 mobile phone.

Jabra HALO2 bluetooth headset connected
Headset shown in playback devices
Headset’s Bluetooth services

Do a clean install of Windows 8 with an upgrade key

There are times when you have to do a clean install of your Windows 8 but if you have just an upgrade key you need to make couple of extra hoops before you can activate the new install. The upgrade key doesn’t prevent you installing to a clean disk but when you try to activate, you get an error 0x8007007B, saying your product key can only be used for upgrading. Another fine example how Microsoft makes things complicated for legitimate users.

Fortunately there’s a way to fix that issue as Lifehacker’s article tells:

  • Open the Registry Editor (Win + R, type regedit).
  • Navigate to “HKEY_LOCAL_MACHINE/Software/Microsoft/Windows/CurrentVersion/Setup/OOBE/” and change the MediabootInstall key’s value from 1 to 0.
  • Open the Command Prompt (Win + R, type cmd). Right-click on the Command Prompt icon and run it as an administrator.
  • Type slmgr -rearm and press Enter.
  • Reboot Windows.

After that is done and you get back into Windows, you should be able to run the Activation utility and activate Windows as normal, without getting an error.

Apparently you can also call Microsoft Support and they will walk you through the proper way doing this because they understand you may have bought a new drive. There is a dialog you can get to in system tools where it will ask you for a numerical code. The support personnel will give you the number, you click “OK” after typing it in, then go the activation again and it works. This process is likely doing the work around mention above, but through an approved administrative process.

By the way, restarting Windows 8 is most easily done by left-clicking once on an empty spot on the desktop and holding Alt + F4).

Setting up LAMP stack on OS X

Setting up LAMP stack for web development on OS X can be done with 3rd party software like MAMP but as Mac OS X comes with pre-installed Apache and PHP it’s easy to use the native setup. You just need to configure Apache, PHP and install MySQL.

Setup Apache2

Set up the Server Name to localhost to suppress the warning about fully qualified domain name and enable PHP module.

$ sudo vim /etc/apache2/httpd.conf
ServerName localhost:80
LoadModule php5_module libexec/apache2/libphp5.so

Create “virtual hosts” under your Sites. Change the username to your account’s username.

~$ sudo vim /etc/apache2/users/username.conf
<VirtualHost *:80>
  ServerName dev
  DocumentRoot /Users/username/Sites
  VirtualDocumentRoot /Users/username/Sites/%-2/htdocs
  UseCanonicalName Off
 
  <Directory "/Users/username/Sites/*/htdocs">
    AllowOverride All
    Order allow,deny
    Allow from all
  </Directory>
</VirtualHost>

Now Apache serves your projects from your home directory’s Sites folder. Apache will serve files from the htdocs folder like “~/Sites/projectname/htdocs”.

Now just restart Apache and check that it’s running.

$ sudo apachectl restart
$ ps aux | grep httpd

Setup PHP

$ sudo cp /etc/php.ini.default /etc/php.ini

Edit php.ini for easier debugging:

error_reporting  =  E_ALL | E_STRICT
display_errors = On
html_errors = On

Setup MySQL

MySQL can be installed directly from Oracle’s MySQL packages or by using Homebrew.

Install Homebrew

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Install MySQL using Homebrew

$ brew install mysql

Install the MySQL system tables and have it run as your system user:

$ unset TMPDIR
$ mysql_install_db --verbose --user=`whoami` --basedir="$(brew --prefix mysql)" --datadir=/usr/local/var/mysql --tmpdir=/tmp

Start MySQL and check that it’s running

$ mysql.server start
$ ps aux | grep mysql

Reset the root password. Change the “5.5.27” to your installed version number.

$ /usr/local/Cellar/mysql/5.5.27/bin/mysqladmin -u root password 'YOUR_NEW_PASSWORD'

As we are using the Homebrew package for MySQL and the default php.ini file then PHP is trying to connect to MySQL through the default_socket at /var/mysql/mysql.sock which doesn’t exist as MySQL is using /tmp/mysql.sock. Just change all instances of /var/mysql/mysql.sock to /tmp/mysql.sock.

$ sudo sed -i "" "s:/var/mysql/mysql.sock:/tmp/mysql.sock:g" /etc/php.ini

And you’re done.

Web application test automation with Robot Framework

Software quality has always been important but seems that lately it has become more generally acknowledged fact that quality assurance and testing aren’t things to be left behind. With Java EE Web applications you have different ways to achieve test coverage and test that your application works with tools like JUnit, Mockito and DBUnit. But what about testing your web application with different browsers? One great way is to use Robot Framework which is a generic test automation framework and when combined with Selenium 2 it makes both writing your tests and running them quite intuitive.

Contents

Introduction

Robot Framework which is a generic test automation framework for acceptance testing and its tabular test data syntax is almost plain English and easy to understand. Its testing capabilities can be extended by test libraries implemented either with Python or Java, and users can create new higher-level keywords from existing ones using the same syntax that is used for creating test cases. Robot Framework itself is open source and released under Apache License 2.0, and most of the libraries and tools in the ecosystem are also open source. The development of the core framework is supported by Nokia Siemens Networks.

Robot Framework doesn’t do any specific testing activity but instead it acts as a front end for libraries like Selenium2Library. Selenium2Library is a web testing library for Robot Framework that leverages the Selenium 2 (WebDriver) libraries from the Selenium project. In practice it starts the browser (eg. IE, Firefox, Chrome) and runs the tests against it natively as a user would. There’s no need to manually click through the user interface.

Robot Framework has good documentation and by going through the “Web testing with Robot Framework and Selenium2Library” demo you see how it’s used in web testing, get introduction to test data syntax, how tests are executed, and how logs and reports look like. For more detailed view about Robot Framework’s features you can read the User Guide.

Installing test tools

The “Web testing with Robot Framework and Selenium2Library” demo is good starting point for getting to know Robot Framework but it more or less skips the details of setting up the system and as the installation instructions are a bit too verbose here is an example how to install and use Robot Framework and Selenium 2 in 64-bit Windows 7.

Python installation

First we need Python as a precondition to run Robot Framework and we install Python version 2.7.x as Robot Framework is currently not compatible with Python 3.x. From the Python download page select Python 2.7.9 Windows X86-64 Installer.

For using the RIDE editor we also need wxPython. From the download page select wxPython2.8-win64-unicode-py27 for 64-bit Python 2.7.

Next we need to set up the PATH environment variable in Windows if you didn’t setup it when you installed Python.

Open Start > Settings > Control Panel > System > Advanced > Environment Variables
Select System variables > PATH > Edit and add e.g. ;\Python27;C:\Python27\Scripts at the end of the value.
Exit the dialog with OK to save the changes.

Starting from Python 2.7.9, the standard Windows installer by default installs and activates pip.

Robot Framework and Selenium2Library installation

In practice it is easiest to install Robot Framework and Selenium2Library along with its dependencies using pip package manager. Once you have pip installed, all you need to do is running these commands in your Command Prompt:

1. pip install robotframework
2. pip install robotframework-selenium2library

It’s good to notice that pip has a “feature” that unless a specific version is given, they install the latest possible version even if that is an alpha or beta release. A workaround is giving the version explicitly. like pip install robotframework==2.7.7

RIDE installation

RIDE is a light-weight and intuitive editor for Robot Framework test case files. It can be installed by using Windows installer (select robotframework-ride-1.1.win-amd64.exe) or with pip using:

pip install robotframework-ride

The Windows installer does a shortcut to the desktop and you can start it from Command Prompt with command ride.py.

Now you have everything you need to create and execute Robot Framework tests.

Executing Robot Framework tests

As described in WebDemo running tests requires the demo application located under demoapp directory to be running. It can be started by executing it from the command line:

python demoapp/server.py

After the demo application is started, it is be available at http://localhost:7272 and it needs to be running while executing the automated tests. It can be shut down by using Ctrl-C.

In Robot Framework each file contains one or more tests and is treated as a test suite. Every directory that contains a test suite file or directory is also a test suite. When Robot Framework is executed on a directory it will go through all files and directories of the correct kind except those that start with an underscore character.

WebDemo’s test cases are located in login_tests directory and to execute them all type in your Command Prompt:

pybot login_tests

Running the tests opens a browser window which Selenium 2 is driving natively as a user would and you can see the interactions.
When the test is finished executing four files will have been generated: report.html, log.html and output.xml. On failed tests selenium takes screenshots which are named like selenium-screenshot-1.png. The browser can also be run on a remote machine using the Selenium Server.

You can also run an individual test case file and use various command line options (see pybot –help) supported by Robot Framework:

pybot login_tests/valid_login.txt
pybot --test InvalidUserName --loglevel DEBUG login_tests

If you selected Firefox as your browser and get an error like “Type Error: environment can only contain strings” that’s a bug in Selenium’s Firefox profile. You can fix it with a “monkey patch” to C:\Python27\Lib\site-packages\selenium\webdriver\firefox\firefox_profile.py.

Using different browsers

The browser that is used is controlled by ${BROWSER} variable defined in resource.txt resource file. Firefox browser is used by default, but that can be easily overridden from the command line.

pybot --variable BROWSER:Chrome login_tests
pybot --variable BROWSER:IE login_tests

Browsers like Chrome and Internet Explorer require separate Internet Explorer Driver and Chrome Driver to be installed before they can be used. InternetExplorerDriver can be downloaded from Selenium project and ChromeDriver from Chromium project. Just place them both somewhere in your PATH.

With Internet Explorer Driver you can get an error like “‘Unexpected error launching Internet Explorer. Protected Mode settings are not the same for all zones. Enable Protected Mode must be set to the same value (enabled or disabled) for all zones.'”. As it reads in the driver’s configuration you must set the Protected Mode settings for each zone to be the same value. To set the Protected Mode settings in Internet Explorer, choose “Internet Options…” from the Tools menu, and click on the Security tab. For each zone, there will be a check box at the bottom of the tab labeled “Enable Protected Mode”.

Reading the results

After the tests have run there are couple of result files to read: report.html and log.html.

The report.html shows the results of your tests and its background is green when all tests have passed and red if any have failed. It also shows “Test Statistics” for how many tests have passed and failed. “Test Details” shows how long the test took to run and, if it failed, what the fail message was.

The log.html gives you more detailed information about why some test fails if the fail message doesn’t make it obvious. It also gives a detailed view of the execution of each of the tests.

Summary

From the short experience I have played with Robot Framework it seems to be powerful tool for designing and executing tests and good way to improve your application’s overall quality.

Next it’s time to get to know the Robot Framework syntax better, write some tests and run Selenium Server. Also the Maven plugin and RobotFramework-EclipseIDE plugin looks interesting.

References

Robot Framework documentation
Robot Framework User Guide
Web testing with Robot Framework and Selenium2Library demo
RIDE: light-weight and intuitive editor for Robot Framework test case files

Running FishEye & Crucible as a service in Linux

Atlassian’s tools for supporting software development are great but they aren’t really admin friendly to start with. For example FishEye & Crucible doesn’t ship with scripts to start it at system boot time but with the help of Atlassian’s Wiki, sysadmin tasks and scripts you can run it as a normal service. First we create a dedicated user for crucible and second we add a new service for it. I have done this on CentOS 5.7 x86_64.

Setting up the service account

As the root user, create a separate “FishEye & Crucible” service account at root shell:

# useradd -c "FishEye & Crucible service account" -d /home/crucible -m crucible

To make it easier for this to work also after FishEye & Crucible upgrades we create a symbolic link to the latest version (modify “/opt/fecru” to match your deployment).

# ln -s /opt/fecru/fecru-2.7.15 /opt/fecru/latest

Then, ensure that this user is the filesystem owner of the FishEye & Crucible instance (modify “/opt/fecru” to match your deployment).

# chown -R crucible:crucible /opt/fecru

Running Crucible as a crucible user

Save the following script to /etc/init.d/crucible. Be sure to edit the FISHEYE_HOME value to the location where your FishEye/Crucible instance resides:

#!/bin/bash
# RUN_AS: The user to run fisheye & crucible as. Its recommended that you create a separate user account for security reasons
RUN_AS=crucible
 
# FISHEYE_HOME: The path to the FishEye & Crucible installation. Its recommended to create a symbolic link to the latest version so the process will still work after upgrades.
FISHEYE_HOME="/opt/fecru/latest"
# FISHEYE_INST: The path where the data itself will be stored.
export FISHEYE_INST="/opt/fecru/fecru-data"

fisheyectl() {
        if [ "x$USER" != "x$RUN_AS" ]; then
                # If running without FISHEYE_INST
                # su - "$RUN_AS" -c "$FISHEYE_HOME/bin/fisheyectl.sh $1"
                su - "$RUN_AS" -c "FISHEYE_INST=$FISHEYE_INST $FISHEYE_HOME/bin/fisheyectl.sh $1"
        else
                "$FISHEYE_HOME/bin/fisheyectl.sh $1"
        fi
} 

case "$1" in
        start)
                fisheyectl start
                ;;
        stop)
                fisheyectl stop
                ;;
        restart)
                fisheyectl stop
                sleep 10
                fisheyectl start
                ;;
        *)
                echo "Usage: $0 {start|stop|restart}"
esac
 
exit 0

After saving the script, modify it’s permissions so that it can be executed:

# chmod 755 /etc/init.d/crucible

Running Crucible as a service

Now that we have an init script we can add it as a service and be able to configure the system to run the script on startup (more precisely, ensure that Crucible runs in runlevels 3, 4 and 5):

chkconfig --add crucible
chkconfig crucible on

Verify that the script has been installed correctly:

# chkconfig --list crucible

After this has been done you can manually start or stop the service by using these commands:

service crucible stop
service crucible start

And you’re done.

JSF 1.2 and getting selected value from dropdown

JSF 1.2 has some weird features which you just have to know if you haven’t read the documents. One example is getting a value from h:selectOneMenu dropdown after onchange event. The first what comes to mind is to use binding attribute with RichFaces’ a4j:support for rerendering elements after the event but it doesn’t work like you thought it would. In some cases using the binding attribute works just fine but as the binding attribute should refer to a request scoped bean property, not a session scoped one, you might get “Duplicate id error” when switching pages back and forth.

Fortunately there is valueChangeListener in h:SelectOneMenu which you can trick to do almost the same. It is executed during Validations phase, before the “Update Model Values” phase and is intended to get a handle of both the old and new value so that you can do some business stuff based on the real change. However, you can use it to invoke actions on a dropdown change only by combining it with onchange="submit()" and immediate="true" and the selected value is to be obtained by ValueChangeEvent#getNewValue(). (StackOverflow, BalusC)

For example:

Jspx:
<h:selectOneMenu value="#{fooBean.object.value}" 
	valueChangeListener="#{fooBean.statusChanged}" 
	onchange="submit()" immediate="true">
	<f:selectItem itemLabel="" itemValue=""/>
	<f:selectItems value="#{fooBean.selectValuesList}"/>
</h:selectOneMenu>
 
Java:
public void statusChanged(ValueChangeEvent event) {
	if (event.getNewValue() != null && 
		StringUtils.hasText((String) event.getNewValue())) {
		// ... Do something with the new value
	}
}

The negative side of using onchange="submit()" is that the form is submitted, validated and you don’t get the same dynamic feeling like with a4j:support.

In JSF 2 things are easier as you don’t need the valueChangeListener and you can use the listener attribute of instead.

Using CAcert.org signed certificates for TLS

Setting up Transport Layer Security (TLS), or as previously known as Secure Sockets Layer (SSL), for Apache, Postfix and IMAP like Dovecot is fairly easy. You just need some digital certificates and configuration. If you don’t want to pay for certificates from trusted sources like Thawte or you just don’t need that kind of trust (for development purposes), you can always produce your own certificates. But there is also a middle way: using CAcert.org signed certificates.

Background
Wikipedia tells us that CAcert.org is a community-driven certificate authority that issues free public key certificates. CAcert automatically signs certificates for email addresses controlled by the requester and for domains for which certain addresses (such as “hostmaster@example.com”) are controlled by the requester. Thus it operates as a robot certificate authority. CAcert certificates can be used like any other SSL certificates although they are considered weak because CAcert does not emit any information in the certificates other than the domain name or email address. To create higher-trust certificates, users can participate in a web of trust system whereby users physically meet and verify each other’s identities. They are also not as useful in web browsers as certificates issued by commercial CAs such as VeriSign, because most installed web browsers do not distribute CAcert’s root certificate. Thus, for most web users, a certificate signed by CAcert behaves like a self-signed certificate.

Generating Certificates
The procedure to sign your certificate at CAcert is rather simple. This guide assumes that the certificates are in /etc/ssl/cacert/ and you are as root.

0. Join CAcert.org and fill in your details. After email verification and login, add domain and service will try to verify that you can read mail on one of following accounts: root, hostmaster, postmaster, admin, webmaster or email addresses that can be found on whois data of domain that you provided.

1. Generate a private key that is not file encrypted:

openssl genrsa -out domainname.key 1024
chown root:root domainname.key
chmod 0400 domainname.key

Private keys should belong to “root” and be readable only by root.

You could also create a private key that is encrypted: openssl genrsa -des3 -out domainname.key 1024

2. Create a CSR with the RSA private key (output will be PEM format). Do not enter extra attributes at the prompt and leave the challenge password blank (press enter):

openssl req -new -key domainname.key -out domainname.csr

3. Verify the contents of the CSR or private key:

openssl req -noout -text -in domainname.csr
openssl rsa -noout -text -in domainname.key

4. Send your public key to be signed by and request new server certificate from CAcert.org web site (Class 1 certificate). When you are asked for CSR paste content of domainname.csr. It should look like this:

-----BEGIN CERTIFICATE REQUEST-----
MIIB3TCCAUYCAQAwgZwxCzAJBgNVBAYTAkZJMRAwDgYDVQQIEwdVdXNpbWFhMQ8w
...clip...
MQ==
-----END CERTIFICATE REQUEST-----

You can verify the content of request before sending it

openssl req -in domainname.csr -text -verify -noout

5. Copy the Server Certificate from the CAcert.org webpage and put it in domainname.crt file and add permissions.

chmod a=r domainname.crt

Check at least the contents of Validity and Subject fields:

openssl x509 -in domainname.crt -text -noout

6. Get CAcert.org root certificate

wget -nv https://www.cacert.org/certs/root.crt -O cacert-org.crt
chmod a=r cacert-org.crt

Check the contents:

openssl x509 -in cacert-org.crt -text -noout

After that you’re ready to configure your services like Apache, Postfix and Dovecot to use the new certificate. Read about it later.