This chapter describes how to start using DrJava, including where to get the program and how to run it.
To compile programs in DrJava, you must make sure you have a Java JDK (Java Development Kit) installed on your machine. All Java distributions available for downloading come in two forms: a JDK and a JRE (Java Runtime Environment). A JDK distribution consists of a JRE distribution (a Java Virtual Machine implementation) plus a collection of development tools including javac, a Java compiler, and javadoc, Java documentation generator. DrJava requires a JDK installation because it uses both javac and javadoc as plugin components. Without these components, DrJava can only edit Java programs; it cannot execute them or generate documentation for them. If you do not have a JDK installed already, you can download one for Windows, Linux, or Solaris computers directly from the Oracle webite. Apple Macintosh machines running Mac OS X already have a JDK installed. To download a JDK from the Oracle website, just follow these steps!
Do a search for "JDK"
Select the most recent build of Java from the list of options you see. We recommend Java 6, assuming that you are using a current release of DrJava. Recent releases of DrJava are not compatible with versions of the JDK prior to Java 5 (previously called Java 1.5.0). Older versions of DrJava are compatible with Java 1.3 and Java 1.4.
Click on the link to download the JDK.
Now, install the JDK, and you are ready to install and run DrJava!