private void test() {
    String a = "Valaienie";
    String b = "Maierginle";
    String max = a.length() > b.length() ? a : b;
    String min = a.length() < b.length() ? a : b;
    String temp = null;
    for (int i = 0; i < min.length(); i++) {
        for (int j = min.length(); j >= i; 
 
j--) {
            String substring = min.substring(i, j);//從小的字串開始，從左向右移位比較
            Log.i("tag", "substring:" + substring);
            if (max.contains(substring)) {
                if (TextUtils.isEmpty(temp) || temp.length() < substring.length()) {
                    Log.i("tag", "temp:" + temp);
 
                    temp = substring;
                }
            }
        }
    }
    Log.i("tag", "temp:" + temp);
}