It comprises of a Java Virtual Machine and all the class libraries present in production environment, as well as the additional libraries only useful to the developers, and such as internationalization libraries and IDL libraries. The JDK also comes with complete Java Runtime Environment, that is usually called private runtime. This program also helps manage JAR files, javadoc - a documentation generator, that automatically generates documentation from the source code comments, jps - the process status tool, jdb - the debugger, which displays process info for current Java processes, javap - a class file disassembler, and many other components. JDK, as its primary components, has a collection of programming tools, which includes javac, jar, and archiver, with packages related class libraries in a single JAR file.

Java Development Kit (JDK) contains the programs and tools which you need to compile, debug, and then run applets and applications which you've written using Java programming language.

Download jdk 1.6