This is source to run a simple Hadoop sort.
You need Ivy and Ant installed properly. I had to symlink ivy.jar:
$ cd /usr/share/ant/lib
$ ln -s /usr/share/java/ivy.jar
The you can run this demo like so:
$ ant
Ivy downloads all the dependencies; Hadoop runs locally in single-node mode and makes a Sequence file in /tmp full of random integers; Sorts; and output the Sorted integers.
You can also run these classes inside of Eclipse with the Eclipse-Hadoop plugin. I got it here (hadoop-eclipse-plugin-0.20.3-SNAPSHOT.jar). To install I copied the jar into $ECLIPSE_HOME/dropins.
-KB