Java Extreme Programming Cookbook

Following Hyperlinks

Problem

You want to obtain hyperlinks, simulate clicking on them, and test that the correct response is returned.

Solution

Use the WebResponse.getLinkWith( ) method to obtain a WebLink object, then call WebLink.getRequest( ) to get a new WebRequest that you can execute. Executing this second request simulates the user clicking on the link.

Discussion

The HTTP protocol is a series of requests and responses. Following a hyperlink is merely a case of issuing an HTTP GET request and checking the response. As you are adding new links to your web application, you should attempt to write a test first. The first time you run the test, it fails because the link does not exist. Here is a test that obtains a hyperlink and then attempts to follow it:

public void testFollowLinkToSubscriptionPage(  ) throws Exception {
    // get the home page
    WebConversation webConversation = new WebConversation(  );
    WebResponse response = webConversation.getResponse(
            "http://localhost:8080/news");

    WebLink subscriptionLink = response.getLinkWith("subscription");

    // get a request to simulate clicking on the link
    WebRequest clickRequest = subscriptionLink.getRequest(  );

    // throws HttpNotFoundException if the link is broken
    WebResponse subscriptionPage =
            webConversation.getResponse(clickRequest);
}

The WebResponse.getLinkWith( ) method searches for the first hyperlink in the web page that contains some piece of text. In our example, we are searching for a link like this:

<a href="someUrl">subscription</a> ...