Eclipse fail at launching on Mac OSX

Try deleting:
/YOUR PATH TO WORKSPACE/.metadata/.plugins/org.eclipse.core.resources

Finally, I have solved my problem by myself.

I "simply" re-installed Java. The manipulation is a bit tricky because Java is a part of OSX System and it not supposed to be uninstalled.

How to uninstall Java on OSX?

Download the last update from Apple website (Java for OS X Lion Update 1 - http://support.apple.com/kb/DL1421)

1. Delete /Library/Java, /System/Library/Java, Library/Caches/Java folders

2. Open the Terminal with root (sudo -s)

3. Terminal: pkgutil --packages | grep java

4. Terminal: pkgutil --forget com.apple.pkg.xxxxx (everything about Java)

5. Insert the Mac OS X DVD

6. Terminal: installer -verbose -pkg "/Volumes/Mac OS X Install DVD/System/Installation/Packages/Java.pkg" -target "/Volumes/Macintosh HD"

7. Terminal: installer -verbose -pkg "/Volumes/Mac OS X Install DVD/System/Installation/Packages/JavaTools.pkg" -target "/Volumes/Macintosh HD"

8. Install the Java for OS X previously downloaded

9. Reboot

10. Software update if needed.

source: http://hints.macworld.com/article.php?story=2009051215025819

try some of the suggestions here: my eclipse stopped working today

especially using terminal to run

./eclipse -clean

other potential solutions are these:

When downloading all the Eclipse/Java parts, be sure to save and unpack to an HFS+ partition. If you have, say, a FAT32 partition and save/unpack to there, that will cause installation problems (it happened to me).

Also, there may be issues with the 32-bit/64-bit installers.. be sure to pick the right one