java 查询好友列表 按字母分组排序

//返回实体
public class FriendPO {
	@ApiModelProperty("用户id")
	private Long userId;
	@ApiModelProperty(value = "头像url")
	private String avatar;
	@ApiModelProperty(value = "昵称")
	private String nickName;
	@ApiModelProperty(value = "已有宝物数量")
	private Integer baoNum;
	@ApiModelProperty("备注")
	private String remark;
}





 /**
     * @description: 排序好友列表, 按照昵称分组
     * @params:
     * @return:
     */
    public TreeMap<String, List<FriendPO>> sortByLetterAsc(List<FriendPO> list) {
        //按拼音首字母表排序
        TreeMap<String, List<FriendPO>> letterMap = new TreeMap<>((s1, s2) -> {
            //#号组放到最后
            if ("#".equals(s1) ) {
                return 1;
            }
            if ("#".equals(s2) ) {
                return -1;
            }
            return s1.compareTo(s2);
        });
        if (!CollectionUtils.isEmpty(list)) {
            for (FriendPO t : list) {
                String pinYinFirstLetter = PinYinUtil.getPinYinFirstCharFirstLetter(t.getNickName());
                if (!letterMap.containsKey(pinYinFirstLetter)) {
                    if (pinYinFirstLetter.matches("[A-Z]")) {
                        letterMap.put(pinYinFirstLetter, new ArrayList<FriendPO>());
                    } else {
                        letterMap.put("#", new ArrayList<FriendPO>());
                    }
                }
            }
            for (Map.Entry<String, List<FriendPO>> next : letterMap.entrySet()) {
                List<FriendPO> listTemp = new ArrayList<FriendPO>();
                for (FriendPO t : list) {
                    String pinYinFirstLetter = PinYinUtil.getPinYinFirstCharFirstLetter(t.getNickName());
                    if (next.getKey().equals("#")) {
                        if (StringUtils.isNotBlank(pinYinFirstLetter) && !pinYinFirstLetter.matches("[A-Z]|[a-z]")) {
                            listTemp.add(t);
                            continue;
                        }
                    }
                    if (StringUtils.isNotBlank(pinYinFirstLetter) && next.getKey().equalsIgnoreCase(pinYinFirstLetter)) {
                        listTemp.add(t);
                    }
                }
                List<FriendPO> value = next.getValue();
                value.addAll(listTemp);
            }
        }
        return letterMap;
    }




/**
     * @description: 将字符串转成拼音,只要首字符的首字母
     * @params:
     * @return:
     */
    public static String getPinYinFirstCharFirstLetter(String chinese) {
        if (StringUtils.isBlank(chinese)){
            return "";
        }
        char spell = chinese.toCharArray()[0];
        String pinYin = String.valueOf(spell);
        HanyuPinyinOutputFormat defaultFormat = new HanyuPinyinOutputFormat();
        //大写
        defaultFormat.setCaseType(HanyuPinyinCaseType.UPPERCASE);
        //无语调
        defaultFormat.setToneType(HanyuPinyinToneType.WITHOUT_TONE);

    if (spell > 128) {
        try {
            String[] strings = PinyinHelper.toHanyuPinyinStringArray(spell, defaultFormat);
            if (ArrayUtils.isNotEmpty(strings)) {
                pinYin = String.valueOf(strings[0].charAt(0));
            }
        } catch (BadHanyuPinyinOutputFormatCombination e) {
            log.error(pinYin + "转换错误,返回原值");
            return pinYin;
        }
    }
    return pinYin;
}