从一串字符串中匹配URL地址 正则 (可以没有http或https开头)

/**
* 从字符串中截取出url地址
*
* @param text
* @return
*/
public static String getUrl(String text) {
Pattern pattern = Pattern.compile("((http[s]{0,1}|ftp)://[a-zA-Z0-9\\.\\-]+\\.([a-zA-Z]{2,4})(:\\d+)?(/[a-zA-Z0-9\\.\\-~!@#$%^&*+?:_/=<>]*)?)|((www.)|[a-zA-Z0-9\\.\\-]+\\.([a-zA-Z]{2,4})(:\\d+)?(/[a-zA-Z0-9\\.\\-~!@#$%^&*+?:_/=<>]*)?)");
Matcher matcher = pattern.matcher(text);
StringBuffer buffer = new StringBuffer();
while (matcher.find()) {
buffer.append(matcher.group());
}
return buffer.toString();
}

((http[s]{0,1}|ftp)://[a-zA-Z0-9\.\-]+\.([a-zA-Z]{2,4})(:\d+)?(/[a-zA-Z0-9\.\-~!@#$%^&*+?:_/=<>]*)?)|((www.)|[a-zA-Z0-9\.\-]+\.([a-zA-Z]{2,4})(:\d+)?(/[a-zA-Z0-9\.\-~!@#$%^&*+?:_/=<>]*)?)