Error occurred during initialization of VM

Good post on resolving the error:

Error occurred during initialization of VM Unable to load dependent libraries: Can't find dependent libraries

The culprit is too many java.exe's and the wrong one being put to use.

http://geekycoder.wordpress.com/2009/07/08/java-tips-adventure-in-resolving-the-java-error-error-occurred-during-initialization-of-vm/

What I am curious about is how did the java.exe get in the Windows directory that caused this error? Not going further with this (I'm busy) but the things I did recently include upgrading to the latest version of Java which I did twice due to putting it in a directory I didn't want it in the first time around, install some software from Fluke Networks, and go to a bunch of Java programming pages on the net. While looking at one of them an error was thrown. Not sure that was related to the web site or just a coincidence.

Oh well, renamed all the java.exe's except the one I wanted so they wouldn't get run and put the path to the one I intended to use on my system path so all good it seems.

Using JavasScript and Ant

If you hate the fact that you are doing programming like tasks with XML in Ant, consider using JavaScript if you don't want to write new custom Java classes to use as targets. I would probably opt for new targets but some people seem to prefer scripting languages so here you go:

JavaScript and Ant

In general I try to keep the configuration in the XML file separate from the executable code, which is why I would opt for custom Java class targets configured by XML, rather than try to incorporate executable code into an XML file. That's just me.

I also read you can integrate Groovy with Ant.

Conditionally Call and Ant Target

If you want to set a target to only run if you set a particular value, easy. Just use the if attribute as follows:

<target name="whatever" if="my.value">
  <echo message="target executed"/>
</target>

If you want the above target to run - set my.value to something in your property file before that target and it will run.

<property name="my.value" value="yada"/>

If you leave the property out of your file altogether the target won't run.

You can also have other tasks set values and use those values to determine if targets should run or not based on whether a file was available, etc. Details about conditional values can be found in the Ant FAQ:

Conditionally Execute Ant Target

Ant - Copy Files That Have Changed

If you want to copy files that have changed from one directory to another use a file set with the "modified" option like this:

 <copy todir="${dir.copy.to}">
  <fileset dir="${dir.copy.from}">
         <modified/>
        </fileset>
        
 </copy>

Ant will set up a cache.properties file which tracks file information so it knows the state of files after each build. Then when it runs a task it can refer to the cache file to determine which files have changed since the last successful build and need to be included in the fileset.

If you want the build to include a file that is getting excluded by the cache file just delete that file from the cache.properties file and it will be included in the file set the next time the ant build is run.