确定字符有无重复

import java.util.*;

public class Different {
	public boolean checkDifferent(String iniString) {
		LinkedHashMap<Character, Integer> map = new LinkedHashMap<Character, Integer>();
		char[] ch = iniString.toCharArray();
		for (int i = 0; i < ch.length; i++) {
			if (map.containsKey(ch[i])) {
				int time = map.get(ch[i]);
				map.put(ch[i], ++time);
			} else
				map.put(ch[i], 1);
		}

		for (int i = 0; i < ch.length; i++) {
			if (map.get(ch[i]) > 1)
				return false;
		}
		return true;

	}
}