Java给指定URL字符串添加值和获取URL字符串中的参数值

/**
 * 在指定url后追加参数
 * @param url
 * @param data 参数集合 key = value
 * @return
 */
private static String appendUrl(String url, Map data) {
    String newUrl = url;
    StringBuffer param = new StringBuffer();
    for (String key : data.keySet()) {
        param.append(key + "=" + data.get(key).toString() + "&");
    }
    String paramStr = param.toString();
    paramStr = paramStr.substring(0, paramStr.length() - 1);
    if (newUrl.indexOf("?") >= 0) {
        newUrl += "&" + paramStr;
    } else {
        newUrl += "?" + paramStr;
    }
    return newUrl;
}

/**
 * 获取指定url中的某个参数
 * @param url
 * @param name
 * @return
 */
public static String getParamByUrl(String url, String name) {
    url += "&";
    String pattern = "(\\?|&){1}#{0,1}" + name + "=[a-zA-Z0-9]*(&{1})";

    Pattern r = Pattern.compile(pattern);

    Matcher m = r.matcher(url);
    if (m.find( )) {
        System.out.println(m.group(0));
        return m.group(0).split("=")[1].replace("&", "");
    } else {
        return null;
    }
}

public static void main(String[] args) throws Exception {
    // Map param = new HashMap<>();
    // param.put("id", 1);
    // param.put("age", 18);
    // System.out.println(appendUrl("http://test.com", param));
    // System.out.println(appendUrl("http://test.com?name=a", param));
    // String url = "http://test.com?name=abd&id=1&age=18";
    String url = "http://www.xxxxx.com/login.do?#access_token=xxxx&express_id=yyyyy";
    System.out.println(getParamByUrl(url, "express_id"));
}