[java] Getting request URL in a servlet

I want to know the difference between the below two methods of getting a request URL in servlet.

Method 1:

String url = request.getRequestURL().toString();

Method 2:

url = request.getScheme()
      + "://"
      + request.getServerName()
      + ":"
      + request.getServerPort()
      + request.getRequestURI();

Are there any chances that the above two methods will give two different URLs?

The getRequestURL() omits the port when it is 80 while the scheme is http, or when it is 443 while the scheme is https.

So, just use getRequestURL() if all you want is obtaining the entire URL. This does however not include the GET query string. You may want to construct it as follows then:

StringBuffer requestURL = request.getRequestURL();
if (request.getQueryString() != null) {
    requestURL.append("?").append(request.getQueryString());
}
String completeURL = requestURL.toString();