Friday, 17 August 2018

Testing on Windows IE/Edge

I'm using a MacBook Pro, so I don't have easy access to a windows machine for testing web applications on Internet Explorer - or so I thought...

Microsoft have made available virtual machine images (for VirtualBox, Parallels, Vagrant, VMWare, HyperV) of Windows 7 through to 10 so you can run IE and Edge easily.

Note that the VMs expire after 90 days, but if you take a snapshot when you first install the VM you can roll it back later and start again.


Thursday, 16 August 2018

Slow, Buffering, Stuttering Udemy Video

Udemy video has been completely unusable from my home broadband connection. Videos would take minutes to start playing and then continuously stutter and buffer.

Searching for a solution I came across this Reddit post - and I found the solution was to change my DNS to use CloudFlare (

After changing my AppleTV from automatic DNS to manual and using video playback from the Udemy app has been as you would expect. I don't know why this helps, but it seems to have so far.

Tuesday, 30 December 2014

Enabling FileVault on Yosemite

Read the full details here before doing anything:

Enabling disk encryption on OSX Yosemite turns out to be a straightforward process. Simply enable it through Setting/Security & Privacy/FileVault - if you chose not to let your iCloud account unlock your disk (for when you've forgotten your password) you'll have to keep a safe record of the recovery key (it sounds like you only get one oppourtunity to record this) - this triggers a reboot, and then when you log back in you'll be able to monitor the progress of file encryption from the same settings panel.

I have 2 MacBooks:

  • July 2014 Apple MacBook Pro, 2.6GHz Quad-core Intel Core i7, Turbo Boost up to 3.8GHz, 16GB 1600MHz DDR3L SDRAM, 512GB PCIe-based Flash Storage
  • January 2011 Apple MacBook Air, 13 inch display, Core 2 Duo 1.86GHz, 4 Gig RAM 1067 MHz DDR3, 256 Gig SSD
Since disk speed is king, I wanted to measure the effect of enabling FileVault so I found this benchmark script to hopefully capture a meaningful before and after state:

Unfortunately the purge command now needs to be run as sudo - before I enabled FileVault I ran it without sudo so I didn't get accurate read results. I hope though that the write values are accurate - I did multiple runs just to capture a feel for the variability:

Before FileVault (without sudo purge, read results were invalid)

MacBook Air:
  • Write Speed is: 211.474 MB/sec
  • Write Speed is: 211.479 MB/sec
MacBook Pro:
  • Write Speed is: 749.875 MB/sec
  • Write Speed is: 747.208 MB/sec

After FileVault (with sudo purge, read results look reasonable)

MacBook Air:
  • Read Speed is: 177.373 MB/sec
  • Read Speed is: 179.464 MB/sec
  • Write Speed is: 162.953 MB/sec
  • Write Speed is: 162.258 MB/sec 
MacBook Pro:
  • Read Speed is: 764.053 MB/sec
  • Read Speed is: 762.525 MB/sec
  • Write Speed is: 665.999 MB/sec
  • Write Speed is: 692.193 MB/sec
IF this benchmark is valid, taking the BEST case (smallest difference) for write speed on the MBP (747-692) indicates I've lost 55 MB/sec or approximately 7%.  

I was hoping for a more negligible difference, but the real test that matters will be if I notice any significant degradation. 

Friday, 26 December 2014

Customising what gets included from bower dependencies (Brunch)

Sometimes you'll find you need to customise which files get included from a bower dependency.

For example, when using the moment.js library, you'll see (in bower_components/moment/bower.json) that by default 'moment.js' is the only file included:

In my case, I'm using brunch to build the project and I'd prefer to include moment.min.js - plus I want to selectively pick which moment local files to include.

This turns out to be quite easy - brunch understands bower overrides, so in your projects bower.json all you have to do is include an override which tells it which files to use from your dependencies:

Resetting your android device pin

If you've forgotten the PIN for your android device, you can reset it at

This page lets you choose from your registered devices (if you have more than one). From here you can see when it was last used, and where. You have the option of 'Ring', 'Erase', and 'Lock'. Choosing 'Lock' lets you provide a new pin - so next time you access it the new pin should be active.

Friday, 29 August 2014

Intellij tip - Joining multiple lines into one

There are times when you have some code with each statement on its own line, and you want to move it all onto one line.

CSS is where I've needed this the most.

You start off with some code like this:
And really want this:
Intellij has a very simple way to do this by using Ctrl-Shift-J - for more information, see

Monday, 10 February 2014

Finding a use for an iPad 1

I'd noticed that most of the recent applications in the App Store won't install on my iPad 1 anymore. They either need a gyroscope or IOS 6 or 7. My iPad is stuck on IOS 5.

The first problem with this is that I haven't found a way to browse the App Store for applications that ARE compatible. This is incredibly frustrating, since its just left to trial and error finding some that will work.

I'd heard about the 'download the latest version that is compatible' feature, so decided that since my iPad is in awesome condition I'd gift it to my parents - who wouldn't be needing the latest and greatest features.

This hasn't been so simple, and I suspect others might have the same problem so I've tried to document what I've found:

  1. Doing a 'reset' to erase the iPad (before gifting it to someone) will leave you in the unfortunate situation of not being able to install many applications very easily.
  2. At this point, it doesn't seem possible to install applications requiring > IOS 5 via the device - its not compatible so not allowed.
  3. So to work around this, you can use iTunes to 'purchase' applications. Since using iTunes doesn't seem to be aware of your devices, it'll let you purchase anything.
  4. Now you have some purchases, you can return to your device and open the App Store. Go to the 'Purchased' tab and then individually install each application. Hopefully at this point you'll get the 'download the latest version that is compatible' message.
A couple of notes here:

  • I did all of this while connected over the cable to the computer running iTunes.
  • When I first did it, the applications seem to hang while installing, and never completed installing properly. The solution to this was to delete the applications from the device, then return to the 'Purchased' tab and reinstall. (I think the first installation of the apps may have been due to an iTunes sync which failed and never recovered - presumably because they are not compatible. By deleting them and reinstalling them from the iPad itself via the purchased tab, I got the 'install latest compatible' message which resulted in success).
  • Update 1: I am experiencing a lot of crashes on the device - mainly with the App Store and iTunes. I don't know if this happened before I reset/erased the iPad or if it has just started happening now.
Some obvious things could be improved here:

  1. The App Store could let you filter by 'compatible with device x' e.g. only show me those applications that will work on my 'iPad 1'
  2. When you install apps from the device, it could just install the latest compatible version right there (bypassing the need to do anything special).
If I've got any of this wrong, I'd love to hear. It would be extremely useful to be able to EASILY continue using the iPad 1.

Saturday, 17 August 2013

Using Selenium WebDriver to select JSF/PrimeFaces selectOneMenu options

I'm using JBehave with Selenium WebDriver to test my PrimeFaces (JSF2) application. Selecting an option from a SelectOne option list isn't standard though because of the HTML markup generated by the JSF component.

The facelets code to place the selectOneMenu uses the ID 'state':

This generates HTML div blocks with id's prefixed with this components id:

To select an option, I use a method which manipulates the appropriate divs - this can be used as illustrated below:

To reuse this type of utility method, I put it in a base Page Object class:

Monday, 12 August 2013

Some user feedback

I was exporting my banking transactions the other day. It's a much more tedious process than it has to be and after using this for years and not seeing any updates to the site I thought I'd send some feedback - written as stories:

As an Online Banking Customer, I want the system to remember my export preferences so that I can efficiently export my transactions ­ 
  • currently I have to set everything every time (even if you navigate from a selected account, you still have to pick an account) ­ 
  • file format (i.e CSV) ­ 
  • date format (dd/mm/yycc) 
As an Online Banking Customer, I want to export transactions for all my accounts in one go so that I can efficiently export my transactions ­ so I don't have to do them one at a time
  • ideally multiple accounts in one file 
As an Online Banking Customer, I want to be able to access more than 12 months worth of transactions so that I don't have to export so often. ­ 
  • not much history is available online ­and transactions can easily be lost if you don't remember to export frequently enough
And after getting confirmation of my feedback - where everything was on a single line of text without any of the formatting I used:
As an online user, I want formatting to be preserved when I provide feedback so that it can be clearly read and understood. ­
  • my last feedback suggestion removed all cr/lf so it was all printed on one line and not clearly readable ­ 
  • perhaps you could use the markdown format (customers wouldn't need to know, but it may provide an easily way to have some formatting without complicating things)

I was surprised to get a response - most companies don't bother. They reckon they'll be updating the site this year or next year - sounds like a BIG BANG approach, after not much in the way of incremental improvements for years. I guess I'll just have to continue with the tedium for a while yet.

Saturday, 25 May 2013

Exposing the version of your Maven built web application

Sometimes its useful to expose the version of your web application - I find it useful so vsConsole can display the version of the deployed application for each environment on the dashboard. If you build your app with Maven, you can use this code to get the version, and simply wire up a controller/rest endpoint to return it as text/plain. To expose the version of your maven built spring web application, you can use a REST controller like that shown below. Note, you won't see a valid version while running in the IDE - it'll only work when running the Maven built WAR. If you want to add the Jersey dependencies to your spring application try using the following dependency declaration.

Monday, 6 May 2013

Avoid embedding database connection information in your code

I've seen projects where the application code base contains database connection information - passwords and all, or, WAR files are rebuilt for each environment with properties substituted appropriately for the target environment.

Rather than putting database information in the application code, it makes more sense to use a JDNI data source provided by the container. This way the exact same application code is deployed to all environments, and we don't encounter any exposed passwords - since the owner of the container (in production environments the infrastructure/support team) define the data source themselves.

Database access via JNDI data source in Tomcat

In your application server you want to define a data source which points to the database server and schema of your choice. Here, I'm using the H2 database, and assuming this is the DEV Tomcat server, I point it to the DEV schema - define this resource in the Tomcat context.xml:

 <Resource name="jdbc/app1db" auth="Container" type="javax.sql.DataSource"
               maxActive="100" maxIdle="30" maxWait="10000"
               username="sa" password="" driverClassName="org.h2.Driver"
In your TST, UAT, PRD servers you define similar data sources, pointing to the appropriate schemas, all with the same name.

Your application server MUST have the database driver on its classpath, so you will want to add the appropriate driver jar to TOMCAT_HOME/lib.

Other containers such as GlassFish, WebLogic, WebSphere and JBoss will have equivalent ways of achieving this same configuration.

Now, in your application all you need to do is define the JNDI data source, which never changes:

    <bean id="dataSource" class="org.springframework.jndi.JndiObjectFactoryBean">
        <property name="jndiName" value="java:comp/env/jdbc/app1db"/>
With the database connection information encapsulated within the container, you don't need these details in the source code, you don't expose passwords to anyone and you don't need to repackage your application for each environment - deployment is simple. 

Another similar use-case is for the mail server. You may also want to expose a String which could point to a properties file or server address - this can then be referenced in your spring application context.

Below are xml snippets of a Tomcat configuration which exposes some resources and a Spring application context file that uses those resources.

Thursday, 2 May 2013

Deploying to Tomcat 7 with Maven

It's sometimes nice to be able to update a development Tomcat 7 server from Maven - this makes it simple to hook automatic deployment into a CI server or just update the dev server as a developer.

First, the Tomcat manager application needs to be installed (check Tomcat's webapps directory for the manager application) and configured with the appropriate user credentials:

Now, I needed to define the server admin credentials in my maven settings (~/.m2/settings.xml):

Then, I updated the POM to configure the maven tomcat plugin:

Now, using 'mvn tomcat7:redeploy' lets me update the dev server.

Note however, on Windows you may have some problems with undeploying the application - after an undeploy command, some jars may be left over in the webapps/appname directory. When you try to redeploy your app you'll see an error containing "cannot invoke tomcat manager fail - unable to delete...".

To work around this, you can change the TOMCAT_HOME/conf/context.xml to include the 'antiJARLocking' attribute like so:
<Context antiJARLocking="true">
The documentation points out though that this will impact start up times of applications.

In my case, I noticed problems when doing a redeploy to Tomcat - most likely unrelated to Maven and/or the maven tomcat plugin and more to do with PermGen (I saw perm gen OutOfMemory: PermGen space errors in the tomcat7-stderr logs, and the Tomcat process was consuming 100% cpu). Adding the following switches to the Tomcat JVM settings seems to have fixed it for now:
-XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled -XX:PermSize=64m -XX:MaxPermSize=128m -Xmx992M
 (In this instance, I'm running Tomcat 7 as a Windows service on JDK7 with a 50MB WAR file).

Tuesday, 23 April 2013

Exception: AbstractMethodError requires c3p0 upgrade

photo credit: markchadwickart
via photopin cc
I just encountered this exception:
Exception in thread "main" java.lang.AbstractMethodError: com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.setCharacterStream(ILjava/io/Reader;J)V at org.hibernate.type.descriptor.sql.ClobTypeDescriptor$4$1.doBind( at org.hibernate.type.descriptor.sql.BasicBinder.bind(
It turns out that upgrading c3p0 does the trick (from to


Tuesday, 16 April 2013

Week in Review - 2013-16

Print to Google Drive

I just noticed 'Save to Google Drive' in my 'Print' options in Chrome! This is awesome - when you want to save something for reference, and you don't want to go through thousands of bookmarks, this is exactly what I wanted!

Media Problems

Here is a great blog post about trying to find a decent movie streaming service. Now I have FetchTV (this lets me buy movies to stream, much like the Google Play option) I'm considering turning my MythTV media center off, but I still need an option for playing music/displaying photos/etc. There are lots of options, from AppleTV to Western Digital et al media players. Props to Google for actually selling us here in Australia movies and music - unlike Amazon (we still can't buy movies and music from Amazon in 2013).

Andrew Chen quits RSS - WTF!

Andrew Chen just announced that he's quitting RSS in favour of email notifications. Look at the comments though, and there isn't a single positive response (and they are all quite sensible reactions). Presumably this was provoked by Google Reader being retired, but the unanswered question for Andrew is why does Reader == RSS ? I've switch to Feedly (which has a seamless process to migrate your reader account) and I'm liking it so far. I won't even notice Reader go offline.


Friday, 12 April 2013

AspectJWeaver with JDK 7 - error - only supported at Java 5 compliance level or above

I came across this problem with an older project - when I switched from jdk6 to jdk7, when the application started I encountered:
nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'org.springframework.transaction.annotation.AnnotationTransactionAttributeSource#0': Initialization of bean failed; nested exception is java.lang.IllegalArgumentException:  error annotation type patterns are only supported at Java 5 compliance level or above
I didn't want a purely maven solution because during development I run the app in Tomcat via the IDE (Intellij IDEA).

In the end I just upgraded my aspectjweaver dependency to 1.7.2 (it was 1.5.4)

Everything seems okay now.