How to enable java syntax check in eclipse 3.5?

Because I installed a plugin, the java syntax check function is disabled. Does anyone know where I could enable this? suc开发者_如何学Pythonh as: in Window > Preferences.

Thanks Joseph

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Check the nature of your project: if java is no longer part of it, that would explain why there is no longer any Java syntax checking.
(same principle than this blog entry on php nature)

Regarding Aptana Studio, I don't see any obvious ticket on this issue.
Check the perspective you are in.
It may be a new perspective (for PHP or ruby development) in which all Java-related feature are disabled.