Note:
a. The $JAVA_HOME line assumes you are using default OS Java package.
b. To use a different version of Java than the default look at the versions in the
/System/Library/Frameworks/JavaVM.framework/Versions/ folder and set the $JAVA_HOME
variable to the appropriate version
c. I highly recommend using the scripts you create to startup and shutdown tomcat because
I have notices that the $JAVA_HOME variables can be set very weirdly if it is done on
the command line if it is not.

The notes I am sharing here are from the points on in the Ant manual at http://ant.apache.org/manual so you can go to that manual in case you are looking to do something in your build.xml file that I do not talk about here.

The root element of the build file is <project>. You should give your project a name for documentation purposes.

A project has several <target>s. A target is a set of steps to be done to that project. Example targets might be compiling the code, packaging the code into a “.war” file, running tests, etc.

Targets may have dependencies illustrated below:
<target name="compile">...compile the code...</target>
<target name="war" depends="compile">...make the war file...</target>
When the build is done for a target that has dependencies, Ant does the dependency analysis for you.

Targets consists of a set of tasks or actions to be performed. Each task is represented tby an XML element. The list of tasks that comes with Ant can be found at http://ant.apache.org/manual/coretasklist.html. These can be extended with other tasks from other sources.

The list of tasks most commonly used would be: delete, copy, echo, javac, jar, and war.

Delving into the javac task at http://ant.apache.org/manual/CoreTasks/javac.html. We can see that the javac task compiles “.java” files into “.class” files.  A simple javac task might look like:
<javac srcdir="src" destdir="dest" classpath="xyz.jar" source="1.6"/>
The task to perform is to compile everything in the directory ‘src’ into class files in the directory ‘dest’, use the ‘xyz.jar’ for the classpath, and compile them as Java 1.6 classes. Note that compiling the code from the ‘src’ to the ‘dest’ directory keeps the directory file structure from source.

The first example at http://ant.apache.org/manual/CoreTasks/javac.html shows you a variant of the code above because the names of the directories are in ‘properties’, meaning they are actually defined elsewhere and only referenced by name in the task. You can tell because the of the ${} around them; that’s substituting for the ‘src’ and ‘build’ properties defined elsewhere.

The sixth example at http://ant.apache.org/manual/CoreTasks/javac.html shows you the other important thing to know about ant which is that you can often define collections of resources outside of the task tag itself. In this example <src>, <include>, and <exclude> tags define the collections of the resources outside of the javac task tag.

Attached is a sample build.xml file for a project that I recently created:
<?xml version="1.0"?>
<project name="jcUtdJavaApi" default="jar" basedir=".">
<description>A frame work for accessing the UT Direct API in Java</description>
<property name="src" location="src"/>
<property name="test-src" location="test/src"/>
<property name="build" location="build"/>
<property name="dist" location="dist"/>
<property name="lib" location="lib"/>
<path id="build-classpath">
<fileset dir="${lib}"><include name="**/*.jar"/></fileset>
</path>
<target name="clean">
<delete includeemptydirs="true">
<fileset dir="${build}" includes="**/*"/>
<fileset dir="${dist}" includes="**/*"/>
</delete>
</target>
<target name="compile" depends="clean">
<mkdir dir="${build}/classes"/>
<javac srcdir="${src}"
destdir="${build}/classes"
classpathref="build-classpath"
source="1.5"
target="1.5"
debug="true"/>
<copy todir="${build}/classes">
<fileset dir="${src}">
<exclude name="**/*.java"/>
</fileset>
</copy>
</target>
<target name="jar" depends="compile">
<jar jarfile="dist/UTDirect.jar" basedir="${build}/classes" />
</target>
</project>

How was I able to figure out that I changed the extension on the wrong thing? I listed the contents of the jar using the following command:
tar -tf  file.jar
Only then did I notice that the structure of my jar was not correct, so I:

1. converted the package back to a zip
2. unzipped the package
3. located the jar I was supposed to use

And voila my application worked as expected. Now all I have to do is remember that next time.

Consider this debugging tip #2. Until next discovery toodles!

The problem was there was information being added to the request object and I did not notice the type of the information returned from the object. Had I noticed, I would have seen the error of my assumption that the object when it was pulled out of the request object could be cast back to its original type. This post is simple  but it is one of those things that can cost you time.

Look at this as debugging tip #1.

This is me sharing with you what not to do that has taken me hours and several conversations to arrive at. If you are feeling stuck and have a question, do not hesitate to post for help here and hopefully, I can try and help you with a simple problem. This will be an adventure for me as well as you so buckle up and enjoy the ride!