just installed the same yesterday with no problem. Make sure you download the Generic Installer (aka the JAR installer). Then install Java 7 to your MAC and ensure its the default Java version (type java -version on the terminal). Then call java -jar <jdeveloper install file name>.jar from the directory you copied the downloaded files to (by default this is called "Download"). Wait for the installer to pop up (may take a minute) and then install JDeveloper. The install directory then has a JDeveloper / JDev folder that contain the start icon to use for starting the IDE
Thank you!!!!! It worked perfectly!!!!