Java: String representation of just the host, scheme, possibly port from servlet request

Question

I work with different servers and configurations. What is the best java code approach for getting the scheme://host:[port if it is not port 80].

Here is some code I have used, but don't know if this is the best approach. (this is pseudo code)

HttpServletRequest == request

String serverName = request.getServerName().toLowerCase();
String scheme = request.getScheme();
int port = request.getServerPort();

String val = scheme + "://" + serverName + ":" port;

Such that val returns:

http(s)://server.com/

or

http(s)://server.com:7770

Basically, I need everything but the query string and 'context'.

I was also consider using URL:

String absURL = request.getRequestURL();
URL url = new URL(absURL);

url.get????

Answer 1

I think java.net.URI does what you want.

Answer 2

URI u=new URI("http://www.google.com/");
String s=u.getScheme()+"://"+u.getHost()+":"+u.getPort();

As Cookie said, from java.net.URI (docs).

Answer 3

try this:

URL serverURL = new URL(request.getScheme(),      // http
                        request.getServerName(),  // host
                        request.getServerPort(),  // port
                        "");                      // file

EDIT

hiding default port on http and https:

int port = request.getServerPort();

if (request.getScheme().equals("http") && port == 80) {
    port = -1;
} else if (request.getScheme().equals("https") && port == 443) {
    port = -1;
}

URL serverURL = new URL(request.getScheme(), request.getServerName(), port, "");

Answer 4

public String getServer(HttpServletRequest request) {
  int port = request.getServerPort();
  StringBuilder result = new StringBuilder();
  result.append(request.getScheme())
        .append("://")
        .append(request.getServerName());

  if (port != 80) {
    result.append(':')
          .append(port);
  }

  return result;
}

Answer 5

If you want to preserve the URL as it appeared in the request (e.g. leaving off the port if it wasn't explicitly given), you can use something like this. The regex matches HTTP and HTTPS URLs. Capture group 1 contains the server root from the scheme to the optional port. (That's the one you want.) Group 2 contains the host name only.

String regex = "(^http[s]?://([\\w\\-_]+(?:\\.[\\w\\-_]+)*)(?:\\:[\\d]+)?).*$";
Matcher urlMatcher = Pattern.compile(regex).matcher(request.getRequestURL());
String serverRoot = urlMatcher.group(1);