java正则表达式获得html字符串中<img src>的src中的url地址

/**
     * 得到网页中图片的地址
     */
    public static Set<String> getImgStr(String htmlStr) {
        Set<String> pics = new HashSet<>();
        String img = "";
        Pattern p_image;
        Matcher m_image;
        //     String regEx_img = "<img.*src=(.*?)[^>]*?>"; //图片链接地址
        String regEx_img = "<img.*src\\s*=\\s*(.*?)[^>]*?>";
        p_image = Pattern.compile
                (regEx_img, Pattern.CASE_INSENSITIVE);
        m_image = p_image.matcher(htmlStr);
        while (m_image.find()) {
            // 得到<img />数据
            img = m_image.group();
            // 匹配<img>中的src数据
            Matcher m = Pattern.compile("src\\s*=\\s*\"?(.*?)(\"|>|\\s+)").matcher(img);
            while (m.find()) {
                pics.add(m.group(1));
            }
        }
        return pics;
    }