Showing all posts with the category : Errata


Errata for Android course Module 2 Chapter 4

06-Sep-2018 in Errata

In Chapter 4 of the Android course (module 2) the fragment manager is able to "look through" fragments to find nested fragments. Unfortunately this behaviour no longer works in the current version of Android, so a slightly different approach is needed...


Java Advanced Tools - Errata for Thread Safety

04-Jul-2017 in Errata Core Java Threading

In Chapter 20 of the Java Advanced Topics course (the video on Synchronization and Thread Safety), at about 20 mins 15 seconds, I explain that you tend to use the synchronized keyword with the smallest possible code block. I demonstrate this with the following code:


Installing Groovy - which version to go for?

08-May-2017 in Errata Groovy

Since we released the Groovy course, there have been some changes to the hosting of the Groovy distribution files. The newer versions of Groovy are completely compatible with the course, so you're fine to use any, but you'll need to download them from:

Please note that for Windows users, the latest version may not have a windows installer available. To get started quickly you may wish to check a prior version with a Windows installer. At the time of creating this blog post, 2.4.11 is the latest stable version of Groovy, but if you want the Windows installer you'll need to get 2.4.10.


Spring Boot Crashing Due to Unsatisfied Depedency?

16-Oct-2016 in Errata Spring Boot

We've just had a report of a possible bug on our Microservices course - your web application might fail to start up with something like the following in the Stacktrace: [spring-boot-devtools-1.4.1.RELEASE.jar:1.4.1.RELEASE]
Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException:
Error creating bean with name 'positionTrackingExternalService': Unsatisfied dependency expressed through field 'remoteService'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creat...

An update on Hadoop Versions

09-Feb-2015 in Errata Hadoop

Our popular Hadoop for Java Developers course was recorded using version 2.4.0 of Hadoop. Since the course was released there have been some further releases of Hadoop, with the current version being 2.6.0.

There are no differences in the content that we cover on the course between the two versions of Hadoop, so the course is completely valid if you wish to use 2.6.0 or 2.4.0. In this blog post, however, I want to point out a reason to stick with version 2.4.0, and a couple of pointers that you should be aware of if you are going to use 2.6.0. I'll also mention the process to upgrade from 2.4.0 to 2.6.0.

Which Version of Hadoop should I use?

If you're starting to develop with Hadoop today then you might just want to download the latest version from the Hadoop website (2.6.0) and there is only really one reason that I can think of not to do this... and that is that Amazon's Elastic Map Reduce (EMR) service, which can be used to run Hadoop jobs "in the cloud" is not yet compliant with versions of Hadoop newer than 2.4.0.


Hadoop Course - Understanding the Scripts

13-Oct-2014 in Errata Hadoop

Over the last week or so we've had a few support calls asking questions about the scripts provided in chapter 5 of the course, that are used to switch Hadoop between standalone and pseudo-distributed modes.

This post will explain in a bit more detail what each script is and how it works. These are custom scripts that I've developed while working with Hadoop, so you won't (probably!) find them elsewhere on the internet, but I think they make the process of managing Hadoop configurations on a development machine really easy.


Hadoop Course - Setting Environment Variables - correction to chapter 5

03-Oct-2014 in Errata Hadoop

We have just been made aware of an error in the Hadoop course, chapter 5, at approximately 19 minutes in the video. This error has been fixed in and the video was replaced on 22nd October - so this will only affect you if you downloaded chapter 5 before the 22nd October 2014. All customers can download the replacement video if preferred.

The issue relates to the part of the video that deals with setting your environment variables, and instructs you to edit either your .bashrc file (Linux) or .bash_profile (Mac)


Groovy Course Correction - Chapter 21 (Files and Templates)

10-Sep-2014 in Errata Groovy

I've been made aware today (thanks to a customer asking us to help solve a problem with his code relating to chapter 21 of the Groovy course) of a mistake on the video and with the file supplied for this chapter.

In the exercise I set you to practice with templates, I show on screen the file called DailyCheckInTemplate.txt from the practicals and code folder. This is at approximately 15:22 on the video.


Running db-derby with recent releases of Java

03-Mar-2014 in Errata Derby Database

his blog post is an errata item for my Java Fundamentals course, and will also apply for the other Virtual Pair Programmers courses where we use the db-derby database.

I discovered while recording the upcoming Groovy course that there has been a security change in the most recent release of Java ( that has meant that the default configuration for db-derby no longer works. Running db-derby with the startNetworkServer command will result in an error message which says somewhere early on in the error message:

access denied ("" "localhost:1527" "listen,resolve")


Java Fundamentals - follow up post on Automatic Resource Management

06-Dec-2013 in Errata Core Java

This is the second of two follow up videos for the Java Fundamentals course. In this video, I take the Java try with resources statement a little bit further to tidy up the code we created in chapter 26 of the course. 

The video is hosted on youtube - for best viewing results, watch in full screen and choose the HD quality option if that doesn't come up by default when you click on play!


Follow-up video blog on the keyword Static

22-Jun-2013 in Errata Core Java

One of the topics that didn't make it into the Java Fundamentals course was an explanation of the keyword static... so I've done a short follow up video which goes into detail about that. In the video, I cover what the keyword means and how to use it correctly (both static methods and static variables).

The video is hosted on youtube - for best viewing results, watch in full screen and choose the HD quality option if that doesn't come up by default when you click on play!


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