I\'ve just imported a large amount of source code into Eclipse and basically the package name is no longer valid (the code has been moved folders). Is there a way to select
If the package declarations are no longer valid, then all such invalid declarations would appear in the Problems view in Eclipse. If you do not see this view, you can open it from Window-> Show View -> Other... -> Problems (under the General tab).
You can filter on problems in the Problems view and correct easily correctable ones, by choosing the Quick fix option in the context menu (available on a right-click). In your case you should see something similar to the screenshot posted below:

Applying the quick fix options is trivial, as long as you know which one is correct - you would either have to change the package declaration in the class, or the location of the class itself. Unfortunately there is no option to fix the issue across multiple units at one go; you will have to apply the quick fix for every problem.
If you want to filter on problems of only this variety, consider configuring the Problems view to show all errors that have the text content "does not match the expected package" in the error text, as demonstrated in the following screenshots:

