java.util.Scanner class comes with Java 5.0 : you cannot use it with
previous SDK.

I think that "Scanner class" in Google will give you all the answers
you need.

Here's a simple example:

import java.util.Scanner;

public class TestScanner {   
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
               System.out.printf("Message : ");
        String mess = scanner.nextLine();
        System.out.printf("You wrote %s%n", mess);
    }
}

Class java.util.Scanner is available since Java 1.5.
I suspect that your Eclipse project is configured to have an older Java (1.4
for example).

To change it: open the "Properties" dialog for your project, select "Java
Build Path" - "Library" - "Edit", select an JRE 1.5 (may be you'll have to
add the JRE 1.5 first)

You would import java.util.Scanner;
not scanner.

I believe it is new in 1.5, so make sure you have the recent JDK.
See http://mindprod.com/jgloss/jdk.html