日偏移的正则表达式

Question

我想根据用户定义的表达式计算时间偏移量（天数）。该表达式将支持以下关键字：

1. + - ＆gt;增量
2. - - ＆gt;减少
3. D - ＆gt;天
4. W - ＆gt;周
5. M - ＆gt;月
6. WD - ＆gt;工作日（非商业日历的假期）

示例：

+3D means adding 3 days to the offset
-3D means reduce 3 day from the offset
+34M+3D means adding 34 months and 3 days to the offset
+3D+1WD  means adding 3 days and then add one extra working day.

问题是我不知道如何编写正则表达式来处理字符串。有人能给我一些例子吗？

这是我到目前为止尝试的，请注意第二个令牌不正确

Pattern p = Pattern.compile("[+-]+([0-9]+)[WD|D|W|M]");
 Matcher m = p.matcher("+1D-2WD+3M");
while(m.find()){
    System.out.println(m.group(0));
}

结果：

+1D
-2W
+3M

Answer 1

我会去

(([+-])(\d+)(WD|[DWM]))

[+ - ]：+或 - symbol

\ d +：至少一位数

WD：WD

| ：或

[DWM]：D或W或M

Working example

Pattern p = Pattern.compile("(([+-])(\\d+)(WD|[DWM]))");
        Matcher m = p.matcher("+1D-2WD+3M");
        while(m.find()){
            System.out.println(m.group(1));
            // Splitted argument
            System.out.println("Operator : " +  m.group(2));
            System.out.println("Number : " +  m.group(3));
            System.out.println("Period : " +  m.group(4));

        }