在servlet中获取请求URL

Question

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?

Answer 1

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();