How to Retrieve the Complete URL from an HttpServletRequest in Java?

What is the method to obtain the full URL from an HttpServletRequest object in Java?

String completeURL = request.getRequestURL().toString() + "?" + request.getQueryString();

To retrieve the complete URL from an HttpServletRequest object in Java, you can combine the request URL with the query string if present. This process includes understanding the structure of the request and utilizing built-in methods effectively.

String completeURL = request.getRequestURL().toString();
String queryString = request.getQueryString();
if (queryString != null) {
    completeURL += "?" + queryString;
}

Causes

• The structure of the URL can be influenced by various factors including the scheme (HTTP/HTTPS), server name, port, context path, servlet path, and query string.

Solutions

• Use the getRequestURL() method to get the base URL of the request.
• If query parameters are included, use getQueryString() to append them to the base URL.
• Construct the complete URL combining both parts. See the code snippet below.

Mistake: Forgetting to handle cases where the query string is null.

Solution: Always check if the query string is null before appending it to the URL.

Mistake: Assuming that getRequestURL() will always include the protocol (HTTP/HTTPS).

Solution: Utilize request.getScheme() for the protocol and construct the URL accordingly, if needed.