The right place to download the JDK for Java 7 is Java SE Downloads.
All the other links provided above, as far as I can tell, either provide the JRE or Java 6 downloads (incidentally, if you want to run Eclipse or other IDEs, like IntelliJ IDEA, you will need the JDK, not the JRE).
Regarding IntelliJ IDEA - that will still ask you to install Java 6 as it apparently needs an older class loader or something: just follow the instructions when the dialog pop-up appears and it will install the JDK 6 in the right place.
Afterwards, you will need to do the sudo ln -snf
mentioned in the answer above:
sudo ln -nsf /Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents \
/System/Library/Frameworks/JavaVM.framework/Versions/CurrentJDK
(copied here as it was mentioned that "above" may eventually not make sense as answers are re-sorted).
I also set my JAVA_HOME
to point to where jdk_1.7.0_xx.jdk
was installed:
export JAVA_HOME="/Library/Java/JavaVirtualMachines/jdk1.7.0_45.jdk/Contents/Home"
Then add that to your PATH
:
export PATH=$JAVA_HOME/bin:$PATH
The alternative is to fuzz around with Apple's insane maze of hyperlinks, but honestly life is too short to bother.