Wednesday, August 17, 2016

Fix for "HibernateJpaDialect - JDBC Connection to reset not identical to originally prepared Connection" warning

After updating an application to Hibernate 5.1.1 from 5.1.0, I started seeing the following warning:

HibernateJpaDialect - JDBC Connection to reset not identical to originally prepared Connection

I did not find an "explicit" solution on the Internet, but looking through some of the code fixes in the ngrinder project, I figured out that I could fix my problem the same way by adding <prop key="hibernate.connection.release_mode">on_close</prop> to applicationContext.xml:

Thanks for this solution, JunHo!

Friday, August 12, 2016

JMeter in IntelliJ IDEA on Mac OS X

Quick Answer

Manually add the JMeter path at

Preferences » Other Settings » JMeter » JMeter home directory

Long Answer

I wanted to be able to launch JMeter scripts from within IntelliJ IDEA. This is the process I went through to make this happen:

Install JMeter

Having already installed Homebrew, JMeter can be easily installed with the command

brew install jmeter

Install JMeter Plugin in IntelliJ IDEA

Preferences » PlugIns » Search for JMeter » Select JMeter plugin » install » restart IntelliJ

Configure JMETER_HOME

This is where the troubleshooting needed to start. For the quick solution, see the first section. Otherwise, this is the process I went through:

Ideally, one would want things to "just work" after installing JMeter and the plugin. Unfortunately, when I created my first JMeter Run Configuration in IntelliJ, I got the message in the dialog box:

Run Configuration Error: JMeter not found

I eventually found a dialogue box under

Preferences » Other Settings » JMeter

with a helpful indicator that

JMETER_HOME is used by default

Sure enough, when I ran the env command in a Terminal, JMETER_HOME was not there.

To find out what my JMeter home directory was, I did the following in the Terminal

$ which jmeter
/usr/local/bin/jmeter
$ cat /usr/local/bin/jmeter
#!/bin/bash
exec "/usr/local/Cellar/jmeter/3.0/libexec/bin/jmeter" "$@"

So, based on some other information I gathered, the home directory was just above the "bin" directory.

My first attempt was to add the following line to my .bash_profile:

export JMETER_HOME=/usr/local/Cellar/jmeter/3.0/libexec

Sadly, I found this didn't work after rebooting and confirming that it showed up when the env command was executed in the Terminal.

I eventually ran across Setting global environment variables in IntelliJ IDEA and other test config goodies, from which I learned that environment variables are not automatically passed to GUI applications in Mac OS X. Nonetheless, Update 2 in the article looked promising.

I then added this line to .bash_profile:

launchctl setenv JMETER_HOME /usr/local/Cellar/jmeter/3.0/libexec

Again, to my frustration, I found that after rebooting and confirming that launchctl getenv JMETER_HOME displayed the correct value in the terminal, that this only worked in IntelliJ when I started IntelliJ, quit completely, and then started it again. I have no idea why the environment variable only seems to get read on the second startup.

So, for my final answer, I just had to go with the manual solution of adding the JMeter home path as an Override in the dialogue box found at:

Preferences » Other Settings » JMeter » JMeter home directory




Friday, August 05, 2016

Extract the icon from an APK file

Using the apk-parser library (https://github.com/caoqianli/apk-parser), I developed the following code that will extract the icon from an APK file. Note that there is no guarantee about what size the icon will be. Enjoy!

Renaming a dependency JAR before buiding a WAR in Maven

I was recently tasked with updating New Relic on our servers. When this was initially set up, the server was set up with a JVM command line option:
-javaagent:/usr/share/tomcat7/webapps/ROOT/WEB-INF/lib/newrelic-3.9.0.jar
When working on updating the version, I wanted to change this so that
  1. We could update the New Relic Agent whenever a new update is available
  2. We would not need to change the JVM command line each time the Agent was updated
To accomplish this, I wanted the New Relic Agent JAR name to always be the same, regardless of the version. I found maven-dependency-plugin through a web search, but ran across a problem where my WAR file was being created before the JAR was downloaded and renamed (using maven-war-plugin). All the examples I ran across used <phase>package</phase>, and while that looked right, I figured that this was still happening in the wrong life cycle phase for what I wanted to do. I resorted to reading the documentation, and with some experimenting found that <phase>prepare-package</phase> did this at the right part of the life cycle.
Here is the plugins section of the working pom.xml:
You do not need to include this dependency in your dependencies section, unless you are actually using it in your code.
We changed the server's JVM command line option to:
-javaagent:/usr/share/tomcat7/webapps/ROOT/WEB-INF/lib/newrelic.jar
And everything worked just great ... once I got the YAML file figured out 😉.

Bonus Notes

  • If you have not worked with YAML before, you will find out quickly that indentation is important to keep the hierarchy of properties right
  • The newrelic.yml file included as an example in the newrelic-java.zip file appears to have an error in it. Specifically, the classloader_excludes property values need to be a commented list on the same line. I got parse errors using the example as-is (i.e., the list is indented with each item on a separate line, and has an extra comma at the end).
  • If you are reading this and setting up a new configuration based on this article, you will also need the newrelic.yml file to end up in the same folder. To that end, place the file in /src/main/webapp/WEB-INF/lib in your Maven-based folder structure.

Wednesday, July 27, 2016

IntelliJ Idea: Can't find gems in Cucumber configurations when using RVM Ruby

I had updated Ruby on my Mac OS X laptop using RVM:

curl -sSL https://get.rvm.io | bash -s stable --ruby
rvm use 2.3 --default

In IntelliJ IDEA Ultimate 2016, I changed my Cucumber configuration to use the "RVM: ruby-2.3.0" SDK.

I then got any number of errors regarding not having gems installed like cucumber, any of the required gems, and then finally the debug gems (ruby-debug-ide and debase).
Run Configuration Error: Cucumber Gem isn't installed for RVM

Initially, I had some success getting rid of errors one by one by manually running "gem install" on the command line for every gem that was missing. However, in the end, I still had the problems with the debug gems not being installed, and getting errors when attempting to have IntelliJ install the debug gems itself.

I finally figured out that the Gems bin directory was incorrect. When I when to

File ➜ ProjectStructure ➜ SDKs ➜ RVM: ruby-2.3.0

and changed Gems bin directory to
/Users/[username]/.rvm/gems/ruby-2.3.0

Then things started working just fine.