I click on command link the random was called but the data on page was not change although i have been edited data on database. Another case, i navigate to other page after that i return but the data is old! Please help me!
Helpful hint: I normally put my persistence code in a separate persistence service javabean that I inject into the backing bean using Spring. It makes things easier to maintain, since I don't have 2 complex products interacting within the same bean.
I think your primary problem is this:
The value attribute of the dataTable tag should not be a method call, it should be a reference to an object that's either a JSF DataModel class or to an array or Collection that JSF can wrap within a DataModel class.
An IDE is no substitute for an Intelligent Developer.