去除字符串中重复字符

import java.util.LinkedHashSet;

public class 去除重复字符串 {

	public static void main(String[] args) {
		String str = "aaaabbbccc";
		char[] arr = str.toCharArray();
		LinkedHashSet<Character> hs = new LinkedHashSet<Character>();
		for (int i = 0; i < arr.length; i++) {
			char ch = arr[i];
			hs.add(ch);
		}
		System.out.println(hs);
	}
}