Question

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Java HTTP getResponseCode returns 200 for non-existent URL

Hello, my goal is to build an application that determines the validity of HTML links, however in my following code :

try
{     
 // create the HttpURLConnection
 URL url = new URL("http://www.thisurldoesnotexist");
 HttpURLConnection connection = (HttpURLConnection) url.openConnection();
 System.out.println("Response code is " + connection.getResponseCode());
} 

the nonsense URL is resolving to an IP address, which I did not expect, and the code returns the product : “Response code is 200”

It seems my approach to distinguishing between actual and non-existent pages is flawed. Does anyone know if I am applying the wrong tools toward determining the validity of web pages . . . i.e., is there a better way to differentiate between existent and non-existent web pages . . . thanks so much,

Answer 1

You could:

1. Resolve the IP from the host of the page
2. Try to connect to port 80 on the resolved IP using plain sockets

This however will add complexity since you will need to make a simple GET request through the socket. Then validate the response so you’re sure that its actually a HTTP server running on port 80.

NMap might be able to help you here.