You do not have to be a Java programmer to install and configure a Jetspeed portal but you will need to have a Java SDK(Software Development Kit) installed. This is not the same as the Java Run-time Library.
Download Java version 5(not version 6). Follow the instructions and choose the default installation configuration.
You will need to set the JAVA_HOME environment variable to the root of the Java installation.
In addition, you will need to add JAVA_HOME/bin or JAVA_HOME\bin (for Windows) to your PATH