2.2.1. Installing Java
The first thing you will need to install on your machine is Java. Jenkins is a Java web application, so
you will need at least the Java Runtime Environment, or JRE to run it. For the examples in this chapter,
you will need a recent version of Java 6 (these examples were written with Java 6 update 17, and the
latest release at the time of writing was Java 6 update 19). If you are not sure, you can check this from
the command line (by opening a DOS console on Windows), and running java -version. If Java is
installed on your machine should get something like this:
$ java -version
java version "1.6.0_17"
Java(TM) SE Runtime Environment (build 1.6.0_17-b04-248-10M3025)
Java HotSpot(TM) 64-Bit Server VM (build 14.3-b01-101, mixed mode)If you don’t have a version already installed, or if your version is an older one, download and install the
latest JRE installer from the Java website^3 , as shown in Figure 2.1, “Installing Java”.
Figure 2.1. Installing Java