Problem: failed to create task or type antlib:org.apache.ivy.ant:retrieve

I've just installed NetBeans 7.1.2. When attempting to run an Ivy project I get the following error:

/home/rsharp/projects/project_name/ant-ivy.xml:5: Problem: failed to create task or type antlib:org.apache.ivy.ant:retrieve
Cause: The name is undefined.
Action: Check the spelling.
Action: Check that any custom tasks/types have been declared.
Action: Check that any <presetdef>/<macrodef> declarations have taken place.
No types or tasks have been defined in this namespace yet
This appears to be an antlib declaration.
Action: Check that the implementing library exists in one of:
        -ANT_HOME/lib
        -the IDE Ant configuration dialogs
BUILD FAILED (total time: 0 seconds)

This was because the default location for Ant in NetBeans is:

/usr/local/netbeans-7.1.2/java/ant

Whereas Ant is actually installed at:

/usr/local/ant

To set this, go to Tools > Options > Miscellaneous > Ant and modify Ant Home.

Ant target shortcuts in NetBeans

To solve some time, Ant targets can be given short cuts in the NetBeans IDE. To do this:

1. Open the build.xml  (e.g. through the Files tab). Within the Navigator tab you will see the file contents (i.e., the targets).
2. RIght click on a target and select Create Shortcut. A wizard will open that lets you configure the shortcut (e.g., toolbar button or a keyboard shortcut).

Writing to a properties file with Ant

I find this useful when I want to change how the application works depending on where and why it is being deployed. This blog post assumes you have Ant installed!

In the build.xml file;

<!-- Add the property file -->

<property file="project.properties"/>

<!--  Write a property to the file with a value based on the target -->

<target name="liveExample">

     <echo message="This target example has the live properties"/>

     <propertyfile

          file="project.properties"

          comment="Setting important system procedure variable to 100">

          <entry key="importantVariable" value="100"/>

          </propertyfile>

</target>

<target name="testExample">

     <echo message="This target example has the test properties"/>

     <propertyfile

          file="project.properties"

          comment="Setting important system procedure variable to 10 for testing purposes">

          <entry key="importantVariable" value="10"/>

          </propertyfile>

</target>

How it works

The properties file (project.properties) has a key/value pair written to it. Based on what target is run, the key has a different value. This allows us to control how the application works based on how we deploy it. For further reading on Ant's PropertyFile task see their manual.