Top Most Java 5 New Feature Generics

package com.myapp.test;

import java.util.ArrayList;
import java.util.Iterator;

public class GenericTest {

    public static void main(String[] args) {
        // OLD Style
        ArrayList oldStyle = new ArrayList();
        oldStyle.add(new String("Hello"));
        oldStyle.add(new String("there"));
        oldStyle.add(new Integer(12)); // ok the old way
        oldStyle.add(new String("whoops"));
        // following loop raise runtime error
        for (Iterator i = oldStyle.iterator(); i.hasNext();) {
            System.out.println("Entry= " + (String) i.next());
        }
        // New Style
        ArrayList<String> newStyle = new ArrayList<String>();
        newStyle.add(new String("Hello"));
        newStyle.add(new String("there"));
        // following line raises compile error so it is commented/
        newStyle.add(new Integer(12));
        // compile error
        newStyle.add(new String("whoops"));
        for (Iterator<String> i = newStyle.iterator(); i.hasNext();) {
            System.out.println("Entry= " + i.next());
        }
    }

}