Refined 7

import java.util.ArrayList;
import java.util.Collections;
import java.util.HashSet;

public class Prog7a<E> {
	@SuppressWarnings("unchecked")
	public static <E extends Comparable<E>> void main(String[] args){

		checkUsage(args);

	    ArrayList<E> array = new ArrayList<>();

	    if (args[0].matches("I|i"))
	        for (int i = 2; i < args.length; i++)
	            array.add((E) new Integer(args[i]));

	     else if (args[0].matches("S|s"))
	         for (int i = 2; i < args.length; i++)
	                array.add((E) new String(args[i]));
	     else
	         for (int i = 2; i < args.length; i++)
	                array.add((E) new Double(args[i]));


	    System.out.println("Original: " + array);
	    System.out.println("  Unique: " + removeDuplicates(array));
	    shuffle(array);
	    System.out.println("Shuffled: " + array);
	    System.out.println(" Maximum: " + max(array));
	}

	public static <E> ArrayList<E> removeDuplicates(ArrayList<E> list) {
		new HashSet<E>(list);
		list = new ArrayList<E>(new HashSet<E>(list));
		return list;

	}

	public static <E> void shuffle(ArrayList<E> list) {
		Collections.shuffle(list);
	}

	public static <E extends Comparable<E>> E max(ArrayList<E> list) {
		return Collections.max(list);
	}

	public static void checkUsage(String[] args)
	{
		if (args.length < 2)
		{
			System.out.println("Please supply more than 2 arguments");
			System.exit(1);
		}
		if (!(args[0]=="s") && (args[0]=="S") &&
			(args[0]=="d") && (args[0]=="D") &&
			(args[0]=="i") && (args[0]=="I")){
			System.out.println("Incorrect format of command.");
			System.exit(1);
		}
	}
}