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 http://www.jetbrains.com/idea/webhelp/joining-lines-and-literals.html

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"
               url="jdbc:h2:tcp://devDbServer/~/dev"/>
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"/>
    </bean>
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(ClobTypeDescriptor.java:114) at org.hibernate.type.descriptor.sql.BasicBinder.bind(BasicBinder.java:92)
It turns out that upgrading c3p0 does the trick (from 0.9.1.2 to 0.9.2.1):

        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.2.1</version>
        </dependency>

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.

Links

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)

<dependency>
   <groupId>org.aspectj</groupId>
   <artifactId>aspectjweaver</artifactId>
   <version>1.7.2</version>
</dependency>
Everything seems okay now.

Monday, 25 March 2013

Week in Review - 2013-13

photo credit: @Doug88888
via photopin cc
Installing Windows Vista

For the first time since I bought it, my old Dell Inspiron 1525 has Windows Vista back on it. It's been running Ubuntu Linux since I got it, so why does it now have Windows again? My children are using computers at school now and they are using Windows - mainly Office. So rather than confuse them with different operating systems it seems more constructive to just give them some consistency and let them have their own computer set up like it is at school. I'm going to have to buy Microsoft Office for them - which after seeing how Libre Office handles clip art, I'm quite happy to do! (MS Office has a nice search and browse for clipart which the kids love and can use well. Libre Office didn't seem to have any search and you were left to click into each folder one at a time to see the clipart - not particularly useful).

Downloading statements

I've just noticed PayPal have an interesting feature - you can download your transaction history, by date range, OR just the transactions since your LAST DOWNLOAD. Awesome - many sites are missing this feature. Some of the online banking sites don't even remember ANYTHING - date range, file type (csv etc) - from one export to another - you have to enter everything for every account. Just amazing.


Nexus 7 Android Tablet

I finally have an Android tablet - I've been thinking about getting a Kindle for a long time as a way to catch up on reading during my daily commute. The paperwhite looked good but I couldn't order it from Amazon because they aren't shipping it to Australia and Dick Smith only just started selling it at $169. So when ShoppingExpress had the Nexus 7 16GB for $199 plus postage, I thought that'd be good. A full tablet instead of an eReader, and a little bit heavier, but I think its a good compromise and I can use it for so much more.


New screen protector for my phone

When I got my HTC Incredible S (on an Optus plan) they put a screen protector on it before giving it to  me. So I never saw the screen without it. The protector had a kind of grainy-ness to it but the screen looked okay. Recently the protector started looking pretty bad and it was time for a new one - and WOW, what a difference. This protector is different, not grainy, totally clear but I assuming its not too good for reflection! It was also very easy to put on since it is a stiffer plastic and doesn't bubble. Right now my screen is looking totally awesome and like a brand new one!

Links



Tuesday, 19 March 2013

Week in Review - 2013-12

Google Reader and Listen

I've been using Google Listen for listening to podcasts since I got my Android phone. It worked well, I would just subscribe to podcasts via Google Reader and drop it in the 'Listen Subscriptions' folder. But now with Google announcing the end of Reader, and Listen has long been abandoned, I'm looking for a suitable alternative. I really liked how I simply had to subscribe to a feed online - if I have to subscribe to things via an app, I'm stuck if I ever want to switch apps. Maybe I'll try Pocket Casts.

LinkedIn Groups

I've noticed that when contributing to LinkedIn groups, its not immediately obvious to others from your profile. Recent comments might show up in your activity stream but they'll soon disappear. If you view your profile, you'll see a Groups section that shows the groups you have joined. Click on one of those and you'll be taken to the Group page and at the top there will an area where you can start a discussion - on the left will be your picture and under that is a tiny link to 'Your activity'. Click on this and you'll be able to navigate your history within this group. You can link to this page using the group id and your   member id. Mine link to Agile and Lean Software Development looks like this:

If you are viewing a discussion, you can click on the picture of a commenter to see their activity. 

I'd prefer it if the groups section of my profile had a link to my activity, so it was easy to see. At the moment no prospective employer would ever find it.

Links

Monday, 18 March 2013

Living without Google Reader and Listen


Since I got my Android phone, I've been using Google Listen to listen to podcasts. I really liked this solution since adding another podcast to my collection was as simple as adding it to my 'Listen subscriptions' folder in Google Reader. All from within my browser, all at the click of a button. Awesome.

Listen may not have been the best podcast player - it didn't let you speed the playback up and didn't have a sleep timer. But it was simple and worked. Pity it was discontinued last year.

Now Reader is on its way out I've had to find a new solution to consume my podcasts. And I've found it in Pocket Casts. This does allow you to speed up playback and set a sleep timer - something particularly useful since I've found podcasts distract me so much I can fall asleep very quickly. I've imported my Reader OMPL file by doing the following:
  1. Read how to export Google Reader feeds here http://lifehacker.com/5990456/google-reader-is-getting-shut-down-here-are-the-best-alternatives
  2. Now email the subscriptions.xml file to yourself
  3. Open the email on your phone and save the subscriptions.xml attachment to your phone - if you are using Gmail you might need to use something like GMail Attachment Download to save the attachment
  4. Use a file manager like ES File Explorer to move the file into the /PocketCasts/opml_import directory
  5. Go to Pocket Casts settings and select the Import & Export option, then click on the 'Import OPML file' option and let it do its stuff.
I really would like it if they had a web interface where I could add and manage subscriptions as easily as I did with Reader - hopefully they'll get there.

To get the subscribed podcasts to automatically download, I had to create a playlist, containing All Podcasts, with 'Auto Download' and 'Only on WiFi' selected.

For RSS consumption, I'm trying Feedly - so far I'm impressed by the presentation and its across all of the platforms - web, Android and IOS.

Saturday, 16 March 2013

Fixing my server 500 errors

I'm slowly working through my broken pages - which were broken during the conversion from WordPress to Blogger. I can see in Google Web Master tools I've still got 22 server 500 errors left. There must have been more like 50 to start with. Its a slow painful process of copying the content from the broken post to a new post. I suspect it may be caused by the original WordPress post having comments - something the Wordpress2Blogger script must not be able to handle and therefore creates an corrupted post. Interestingly, the contents of the post are still viewable via the monthly archive page, but viewing the individual post errors - presumably as it tries to render the comments. If I had time, I'd go look at my WordPress database to confirm this theory but all of my time is being taken with fixing the errors. I cannot recommend using the Wordpress2Blogger script, I'm feeling a lot of pain and I had no help from Blogger support or groups.

Thursday, 14 March 2013

Week in Review - 2013-11

Job interview testing

While job hunting, I've come across one company that seems to have a very good filtering process. First off, you get a series of technical questions which are obviously aimed at finding out how you think or how much you know about technologies applicable to the organisation. I'm sure these questions have been custom written for their environment - which does to some extent convey some information about the potential role. If you pass that, you get an online 2 question Codility test which you have exactly an hour to complete. This is where you actually write code and can verify it compiles and produces the right answers. If you haven't seen Codility before, have a look - as a programmer you can even complete tests to get a 'certificate' you can put on your resume.

Job hunting sites

Some interesting sites when job hunting:

LinkedIn group contributions

I enjoy participating in the groups on LinkedIn, but does anyone know how you can view all of your contributions? Seems to me once you've commented, its up to luck if you can ever find it again. If I'm going to continue, I'll have to print the discussion to PDF so I can remember what I've written. Contributions I've made in the past (couple of years ago) seem to have gone, maybe these were part of the discontinued LinkedIn Answers... I think linked in is missing an opportunity here, I'd like my contributions to be easily found on my profile by potential employers and my network - similar to my StackOverflow profile.

Links