Installing Apple's Java in Mavericks
Mavericks doesn't have Java installed by default. If you try to use the
/usr/bin/java executable from Terminal, it will pop up a dialog prompting you to visit Oracle's site and download a JDK.
If you want to install Apple's Java instead, then run java from a subshell. This will pop up a dialog prompting you to directly install Apple's JDK.
The Java installer stub
/System/Library/Java/Support/CoreDeploy.bundle/Contents/Download\ Java\ Components.app appears to check if it was invoked from an interactive TTY or not, and changes behavior accordingly.