一行代码实现java list去重

List listWithoutDup = new ArrayList(new HashSet(listWithDup));

List<String> listWithoutDup = new ArrayList<String>(new HashSet<String>(listWithDup));

List<String> listWithoutDup = new ArrayList<>(new HashSet<>(listWithDup));

import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;

public class Test {
	public static void main(String[] args) {
		List<String> listWithDup = new ArrayList<String>();
		listWithDup.add("1");
		listWithDup.add("2");
		listWithDup.add("3");
		listWithDup.add("1");

		List<String> listWithoutDup = new ArrayList<String>(new HashSet<String>(listWithDup));
		System.out.println("list with dup:"+ listWithDup);
		System.out.println("list without dup:"+ listWithoutDup);
	}
}