Remove duplicates from ArrayList in Java

Variations

1. Insertion Order must be preserved.
2. Insertion Order need not be preserved,
3. Inserted data is an Object

Code

public class Test2 {
	public static void main(String[] args) {
		List<String> list = new ArrayList<>();
		list.add("Tyson");
		list.add("Justin");
		list.add("Justin");
		list.add("Martin");
		Set<String> set2 = new HashSet<String>(list); //Variation #1 If insertion order is not suppose to be preserved
		System.out.println(set2);
		Set<String> set1 = new LinkedHashSet<String>(list); //Variation # 2If insertion order is suppose to be preserved
		System.out.println(set1);
		list.clear();
		list.addAll(set2); //All the data is 
	}
}