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