Here's what you need to get going with the Splunk SDK for Java.
You'll need Java SE version 6 or higher, which you can download from the Oracle web site (http://www.oracle.com/technetwork/java/javase/downloads/index.html).
If you are using Windows, make sure the JAVA_HOME system variable is set to the directory where the JDK is installed.
For more, see "Java Platform Installation" (http://www.oracle.com/technetwork/java/javase/index-137561.html).
You'll also need Apache Ant, which you can download from the Apache website (http://ant.apache.org/bindownload.cgi).
If you are using Windows, make sure these system variables are correctly set:
For more, see "Installing Apache Ant" (http://ant.apache.org/manual/install.html)