How to add RequestInterceptor and change Referer in BrowserMob-Proxy 2.0 - selenium

Question

I am using BrowserMob-Proxy inside a Selenium test suite. I would like to change the Referer for a few tests. I have added requestInterceptor from the 2.0 docs into our MyProxy class and while it does not generate an error the Referer is not changed.
For now, I am trying to get the requestInterceptor to work in the MyProxy class where the proxy is created. In the end, I would like to be able to specify the Referer in each test.
If anyone has suggestions on getting the requestInterceptor to work please let me know. Here is the MyProxy class. Please let me know if other code examples would be helpful to troubleshoot this.
import org.openqa.selenium.Proxy;
import net.lightbody.bmp.core.har.Har;
import net.lightbody.bmp.proxy.ProxyServer;
import net.lightbody.bmp.proxy.http.BrowserMobHttpRequest;
import net.lightbody.bmp.proxy.http.RequestInterceptor;
public class MyProxy {
private ProxyServer proxy;
private boolean initialized;
public Har endCapture() throws Exception {
Thread.sleep(15000);
return this.proxy.getHar();
}
public Proxy getSeleniumProxy() {
return this.proxy.seleniumProxy();
}
public boolean isInitialized() throws Exception {
return this.initialized;
}
public void start() throws Exception {
int proxyPort = Integer.parseInt(System.getProperty("proxyPort"));
this.proxy = new ProxyServer(proxyPort);
this.proxy.start();
this.proxy.setCaptureHeaders(true);
this.proxy.setCaptureContent(true);
this.proxy.addRequestInterceptor(new RequestInterceptor() {
#Override
public void process(BrowserMobHttpRequest request, Har har) {
request.getMethod().removeHeaders("Referer");
request.getMethod().addHeader("Referer", "http://www.google.com");
}
});
this.initialized = true;
}
public void startCapture() throws Exception{
this.proxy.newHar("MyHar");
}
public void stop() throws Exception {
this.proxy.stop();
this.initialized = false;
}
}

Answer 1

I think the key here is how to test the newly-added header, which is tricky to do manually.
I chose as a test-site: http://headers.cloxy.net/request.php, which simply logs the names and values of all request headers. Having first set up my proxy, I arranged a screenshot to be written after page request completed.
I was able to determine that:
#Override
public void process(BrowserMobHttpRequest req, Har har) {
req.getMethod().removeHeaders("Referer");
req.getMethod().addHeader("Referer", "http://www.google.xyz");
// Some extras
req.getMethod().addHeader("Foo_" + System.currentTimeMillis(), "Bar_" + new java.util.Date());
req.getMethod().setHeader("Lorem_" + System.currentTimeMillis(), "Ipsum_" + new java.util.Date());
}
... successfully adds all the specified headers in both BrowserMob 2.0.0 and 2.1 beta 5. I've confirmed this for each version in Firefox (45), Chrome (49), and PhantomJS.
So, in short:
The OP's header-adding syntax is perfectly fine.
setHeader also works as expected.
BMP version numbers do not affect this (but by all means upgrade to 2.1 as/when it is released)
Browsers do not affect this

Answer 2

Review this issue and see if it describes your problem.
Suggestion is to move to the latest version of BrowserMobProxy which is 2.1.0-beta-5.