"<a\\s*href=\"/Patent/(\\d+)\"\\s*.+?>"

------解决方案--------------------
给你参考一下
Java code

    public static void main(String[] args) {
        String pageContent = "<a href='/Patent/01127847' target='_blank'><a href='/Patent/01127821' target='_blank'><a href='/Patent/01127832' target='_blank'>";
        Pattern pattern2 = Pattern.compile("<a\\s+href=.+?>");
        Matcher matcher = pattern2.matcher(pageContent);
        while (matcher.find()) {
            String strPage = matcher.group();
            System.out.println(strPage.replaceAll("(<a.+/|'\\s+.+>)", ""));
        }
    }

------解决方案--------------------
group(1)

------解决方案--------------------
Pattern pattern2 = Pattern.compile("(?:<a href='/Patent/(.*?)'\\s+target='_blank'>)");

然后group(1)