数据脱敏工具类

从别的地方copy来的，用着还可以。

private static final int SIZE = 6;
    private static final String SYMBOL = "*";

    public static void main(String[] args) {
        String s = "";
        String conceal = toConceal(s);
        System.out.println(conceal);
    }

    public static String toConceal(String value) {
        if (null == value || "".equals(value)) {
            return value;
        }
        int len = value.length();
        int pamaone = len / 2;
        int pamatwo = pamaone - 1;
        int pamathree = len % 2;
        StringBuffer stringBuilder = new StringBuffer();
        if (len <= 2) {
            if (pamathree == 1) {
                return SYMBOL;
            }
            stringBuilder.append(SYMBOL);
            stringBuilder.append(value.charAt(len - 1));
        } else {
            if (pamatwo <= 0) {
                stringBuilder.append(value.substring(0, 1));
                stringBuilder.append(SYMBOL);
                stringBuilder.append(value.substring(len - 1, len));

            } else if (pamatwo >= SIZE / 2 && SIZE + 1 != len) {
                int pamafive = (len - SIZE) / 2;
                stringBuilder.append(value.substring(0, pamafive));
                for (int i = 0; i < SIZE; i++) {
                    stringBuilder.append(SYMBOL);
                }
                if ((pamathree == 0 && SIZE / 2 == 0) || (pamathree != 0 && SIZE % 2 != 0)) {
                    stringBuilder.append(value.substring(len - pamafive, len));
                } else {
                    stringBuilder.append(value.substring(len - (pamafive + 1), len));
                }
            } else {
                int pamafour = len - 2;
                stringBuilder.append(value.substring(0, 1));
                for (int i = 0; i < pamafour; i++) {
                    stringBuilder.append(SYMBOL);
                }
                stringBuilder.append(value.substring(len - 1, len));
            }
        }
        return stringBuilder.toString();
    }