How to clone the OpenJDK Java 8 repository?

The repository is linked on http://openjdk.java.net/. Clone it and execute theget_source.sh script.

$ hg clone http://hg.openjdk.java.net/jdk8/jdk8
$ cd jdk8 && sh get_source.sh

A guide to the OpenJDK repositories and a How to contribute are available, too.

Have a look at the README of the version you want to clone.

After doing what another answer said:

hg clone http://hg.openjdk.java.net/jdk8/jdk8

you also need to run:

sh get_source.sh

to actually clone most of the source code, which is split into multiple sub-repositories.

Related: How can I checkout the OpenJDK from the mercurial repository?