eclipse无法导入java.util？

Question

I recently installed Eclipse 4.3 (Build id: 20130919-0819) onto my Windows 7 x64 machine and imported my old workspace, but all of them had some kind of strange problem (they had red exclamation marks on the project names instead of error x's). So I re-imported one, which got rid of the exclamation mark, but there is exactly one .java source file with errors now.

It says it can't resolve "Import java.util", and of course everything using that also has an error too.

What the heck? Isn't java.util one of the base libraries? Also, I can't seem to find where to download/install packages. Does eclipse have a separate program for that? I seem to remember using a package manager to install a few packages or SDKs or something back when I got eclipse on my Windows XP machine.

BTW yes I selected the x64 windows version, not the x86 one. And if it matters at all, when I tried to unzip it with 7zip, it gave me many errors and wouldn't work, so I tried unzipping with the default windows zip thing and that seemed to work just fine.

Answer 1

import must be spelt with a lower-case "i". Try this!

...additionally, you might be wanting to say "import java.util.*;" because util is a package that contains many objects. The * tells it to import all of those objects!

Answer 2

java.util is the collections framework package name. you need to specify what classes you want to import so you can refer to them using there unqualified names, makes code more readable.

if you want to import all classes in the package use import java.util.*;

if you need to add third party packages to your project, you can use a dependency management tool like maven and this can be easily integrated with eclipse.