Longest Word in Dictionary through Deleting

https://www.lintcode.com/problem/longest-word-in-dictionary-through-deleting/description

import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class Solution {
    /**
     * @param s: a string
     * @param d: List[str]
     * @return: return a string
     */
    public String findLongestWord(String s, List d) {
        // write your code  here
        Collections.sort(d, new Comparator() {
            @Override
            public int compare(String o1, String o2) {
                if (o2.length() == o1.length()) {
                    return o1.compareTo(o2);
                }
                return o2.length() - o1.length();
            }
        });
        test:
        for (int i = 0; i < d.size(); i++) {
            String s1 = d.get(i);
            int index = 0;
            for (char c : s1.toCharArray()) {
                index = s.indexOf(c, index);
                if (index < 0) {
                    continue test;
                }
                index++;
            }
            return s1;
        }
        return "";
    }
}