[java] How to get HTTP Response Code using Selenium WebDriver

I have written tests with Selenium2/WebDriver and want to test if HTTP Request returns an HTTP 403 Forbidden.

Is it possible to get the HTTP response status code with Selenium WebDriver?

For those people using Python, you might consider Selenium Wire, a library for inspecting requests made by the browser during a test.

You get access to requests via the driver.requests attribute:

from seleniumwire import webdriver  # Import from seleniumwire

# Create a new instance of the Firefox driver
driver = webdriver.Firefox()

# Go to the Google home page
driver.get('https://www.google.com')

# Access requests via the `requests` attribute
for request in driver.requests:
    if request.response:
        print(
            request.url,
            request.response.status_code,
            request.response.headers['Content-Type']
        )

Prints:

https://www.google.com/ 200 text/html; charset=UTF-8
https://www.google.com/images/branding/googlelogo/2x/googlelogo_color_120x44dp.png 200 image/png
https://consent.google.com/status?continue=https://www.google.com&pc=s&timestamp=1531511954&gl=GB 204 text/html; charset=utf-8
https://www.google.com/images/branding/googlelogo/2x/googlelogo_color_272x92dp.png 200 image/png
https://ssl.gstatic.com/gb/images/i2_2ec824b0.png 200 image/png
https://www.google.com/gen_204?s=webaft&t=aft&atyp=csi&ei=kgRJW7DBONKTlwTK77wQ&rt=wsrt.366,aft.58,prt.58 204 text/html; charset=UTF-8
...

The library gives you the ability to access headers, status code, body content, as well as the ability to modify headers and rewrite URLs.

It is not possible to get HTTP Response code by using Selenium WebDriver directly. The code can be got by using Java code and that can be used in Selenium WebDriver.

To get HTTP Response code by java:

public static int getResponseCode(String urlString) throws MalformedURLException, IOException{
    URL url = new URL(urlString);
    HttpURLConnection huc = (HttpURLConnection)url.openConnection();
    huc.setRequestMethod("GET");
    huc.connect();
    return huc.getResponseCode();
}

Now you can write your Selenium WebDriver code as below:

private static int statusCode;
public static void main(String... args) throws IOException{
    WebDriver driver = new FirefoxDriver();
    driver.manage().window().maximize();
    driver.get("https://www.google.com/");
    driver.manage().timeouts().implicitlyWait(10, TimeUnit.SECONDS);

    List<WebElement> links = driver.findElements(By.tagName("a"));
    for(int i = 0; i < links.size(); i++){
        if(!(links.get(i).getAttribute("href") == null) && !(links.get(i).getAttribute("href").equals(""))){
            if(links.get(i).getAttribute("href").contains("http")){
                statusCode= getResponseCode(links.get(i).getAttribute("href").trim());
                if(statusCode == 403){
                    System.out.println("HTTP 403 Forbidden # " + i + " " + links.get(i).getAttribute("href"));
                }
            }
        }   
    }   
}

You could try Mobilenium (https://github.com/rafpyprog/Mobilenium), a python package that binds BrowserMob Proxy and Selenium.

An usage example:

>>> from mobilenium import mobidriver
>>>
>>> browsermob_path = 'path/to/browsermob-proxy'
>>> mob = mobidriver.Firefox(browsermob_binary=browsermob_path)
>>> mob.get('http://python-requests.org')
301
>>> mob.response['redirectURL']
'http://docs.python-requests.org'
>>> mob.headers['Content-Type']
'application/json; charset=utf8'
>>> mob.title
'Requests: HTTP for Humans \u2014 Requests 2.13.0 documentation'
>>> mob.find_elements_by_tag_name('strong')[1].text
'Behold, the power of Requests'

You can use BrowserMob proxy to capture the requests and responses with a HttpRequestInterceptor. Here is an example in Java:

// Start the BrowserMob proxy
ProxyServer server = new ProxyServer(9978);
server.start();

server.addResponseInterceptor(new HttpResponseInterceptor()
{
    @Override
    public void process(HttpResponse response, HttpContext context)
        throws HttpException, IOException
    {
        System.out.println(response.getStatusLine());
    }
});

// Get selenium proxy
Proxy proxy = server.seleniumProxy();

// Configure desired capability for using proxy server with WebDriver
DesiredCapabilities capabilities = new DesiredCapabilities();
capabilities.setCapability(CapabilityType.PROXY, proxy);

// Set up driver
WebDriver driver = new FirefoxDriver(capabilities);

driver.get("http://stackoverflow.com/questions/6509628/webdriver-get-http-response-code");

// Close the browser
driver.quit();

Not sure this is what you're looking for, but I had a bit different goal is to check if remote image exists and I will not have 403 error, so you could use something like below:

public static boolean linkExists(String URLName){
    try {
        HttpURLConnection.setFollowRedirects(false);
        HttpURLConnection con = (HttpURLConnection) new URL(URLName).openConnection();
        con.setRequestMethod("HEAD");
        return (con.getResponseCode() == HttpURLConnection.HTTP_OK);
    }
    catch (Exception e) {
        e.printStackTrace();
        return false;
    }
}

I was also having same issue and stuck for some days, but after some research i figured out that we can actually use chrome's "--remote-debugging-port" to intercept requests in conjunction with selenium web driver. Use following Pseudocode as a reference:-

create instance of chrome driver with remote debugging

int freePort = findFreePort();

chromeOptions.addArguments("--remote-debugging-port=" + freePort);

ChromeDriver driver = new ChromeDriver(chromeOptions);`

make a get call to http://127.0.0.1:freePort

String response = makeGetCall( "http://127.0.0.1" + freePort  + "/json" );

Extract chrome's webSocket Url to listen, you can see response and figure out how to extract

String webSocketUrl = response.substring(response.indexOf("ws://127.0.0.1"), response.length() - 4);

Connect to this socket, u can use asyncHttp

socket = maketSocketConnection( webSocketUrl );

Enable network capture

socket.send( { "id" : 1, "method" : "Network.enable" } );

Now chrome will send all network related events and captures them as follows

socket.onMessageReceived( String message ){

    Json responseJson = toJson(message);
    if( responseJson.method == "Network.responseReceived" ){
       //extract status code
    }
}

driver.get("http://stackoverflow.com");

you can do everything mentioned in dev tools site. see https://chromedevtools.github.io/devtools-protocol/ Note:- use chromedriver 2.39 or above.

I hope it helps someone.

reference : Using Google Chrome remote debugging protocol

It is possible to get the response code of a http request using Selenium and Chrome or Firefox. All you have to do is start either Chrome or Firefox in logging mode. I will show you some examples below.

java + Selenium + Chrome Here is an example of java + Selenium + Chrome, but I guess that it can be done in any language (python, c#, ...).

All you need to do is tell chromedriver to do "Network.enable". This can be done by enabling Performance logging.

LoggingPreferences logPrefs = new LoggingPreferences();
logPrefs.enable(LogType.PERFORMANCE, Level.ALL);
cap.setCapability(CapabilityType.LOGGING_PREFS, logPrefs);

After the request is done, all you have to do is get and iterate the Perfomance logs and find "Network.responseReceived" for the requested url:

LogEntries logs = driver.manage().logs().get("performance");

Here is the code:

import java.util.Iterator;
import java.util.logging.Level;

import org.json.JSONException;
import org.json.JSONObject;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.chrome.ChromeOptions;
import org.openqa.selenium.logging.LogEntries;
import org.openqa.selenium.logging.LogEntry;
import org.openqa.selenium.logging.LogType;
import org.openqa.selenium.logging.LoggingPreferences;
import org.openqa.selenium.remote.CapabilityType;
import org.openqa.selenium.remote.DesiredCapabilities;

public class TestResponseCode
{
    public static void main(String[] args)
    {
        // simple page (without many resources so that the output is
        // easy to understand
        String url = "http://www.york.ac.uk/teaching/cws/wws/webpage1.html";

        DownloadPage(url);
    }

    private static void DownloadPage(String url)
    {
        ChromeDriver driver = null;

        try
        {
            ChromeOptions options = new ChromeOptions();
            // add whatever extensions you need
            // for example I needed one of adding proxy, and one for blocking
            // images
            // options.addExtensions(new File(file, "proxy.zip"));
            // options.addExtensions(new File("extensions",
            // "Block-image_v1.1.crx"));

            DesiredCapabilities cap = DesiredCapabilities.chrome();
            cap.setCapability(ChromeOptions.CAPABILITY, options);

            // set performance logger
            // this sends Network.enable to chromedriver
            LoggingPreferences logPrefs = new LoggingPreferences();
            logPrefs.enable(LogType.PERFORMANCE, Level.ALL);
            cap.setCapability(CapabilityType.LOGGING_PREFS, logPrefs);

            driver = new ChromeDriver(cap);

            // navigate to the page
            System.out.println("Navigate to " + url);
            driver.navigate().to(url);

            // and capture the last recorded url (it may be a redirect, or the
            // original url)
            String currentURL = driver.getCurrentUrl();

            // then ask for all the performance logs from this request
            // one of them will contain the Network.responseReceived method
            // and we shall find the "last recorded url" response
            LogEntries logs = driver.manage().logs().get("performance");

            int status = -1;

            System.out.println("\nList of log entries:\n");

            for (Iterator<LogEntry> it = logs.iterator(); it.hasNext();)
            {
                LogEntry entry = it.next();

                try
                {
                    JSONObject json = new JSONObject(entry.getMessage());

                    System.out.println(json.toString());

                    JSONObject message = json.getJSONObject("message");
                    String method = message.getString("method");

                    if (method != null
                            && "Network.responseReceived".equals(method))
                    {
                        JSONObject params = message.getJSONObject("params");

                        JSONObject response = params.getJSONObject("response");
                        String messageUrl = response.getString("url");

                        if (currentURL.equals(messageUrl))
                        {
                            status = response.getInt("status");

                            System.out.println(
                                    "---------- bingo !!!!!!!!!!!!!! returned response for "
                                            + messageUrl + ": " + status);

                            System.out.println(
                                    "---------- bingo !!!!!!!!!!!!!! headers: "
                                            + response.get("headers"));
                        }
                    }
                } catch (JSONException e)
                {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }

            System.out.println("\nstatus code: " + status);
        } finally
        {
            if (driver != null)
            {
                driver.quit();
            }
        }
    }
}

The output looks like this:

    Navigate to http://www.york.ac.uk/teaching/cws/wws/webpage1.html

    List of log entries:

    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Page.frameAttached","params":{"parentFrameId":"172.1","frameId":"172.2"}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Page.frameStartedLoading","params":{"frameId":"172.2"}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Page.frameNavigated","params":{"frame":{"securityOrigin":"://","loaderId":"172.1","name":"chromedriver dummy frame","id":"172.2","mimeType":"text/html","parentId":"172.1","url":"about:blank"}}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Page.frameStoppedLoading","params":{"frameId":"172.2"}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Page.frameStartedLoading","params":{"frameId":"3928.1"}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Network.requestWillBeSent","params":{"request":{"headers":{"Upgrade-Insecure-Requests":"1","User-Agent":"Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Safari/537.36"},"initialPriority":"VeryHigh","method":"GET","mixedContentType":"none","url":"http://www.york.ac.uk/teaching/cws/wws/webpage1.html"},"frameId":"3928.1","requestId":"3928.1","documentURL":"http://www.york.ac.uk/teaching/cws/wws/webpage1.html","initiator":{"type":"other"},"loaderId":"3928.1","wallTime":1.47619492749007E9,"type":"Document","timestamp":20226.652971}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Network.responseReceived","params":{"frameId":"3928.1","requestId":"3928.1","response":{"headers":{"Accept-Ranges":"bytes","Keep-Alive":"timeout=4, max=100","Cache-Control":"max-age=300","Server":"Apache/2.2.22 (Ubuntu)","Connection":"Keep-Alive","Content-Encoding":"gzip","Vary":"Accept-Encoding","Expires":"Tue, 11 Oct 2016 14:13:47 GMT","Content-Length":"1957","Date":"Tue, 11 Oct 2016 14:08:47 GMT","Content-Type":"text/html"},"connectionReused":false,"timing":{"pushEnd":0,"workerStart":-1,"proxyEnd":-1,"workerReady":-1,"sslEnd":-1,"pushStart":0,"requestTime":20226.65335,"sslStart":-1,"dnsStart":0,"sendEnd":31.6569999995409,"connectEnd":31.4990000006219,"connectStart":0,"sendStart":31.5860000009707,"dnsEnd":0,"receiveHeadersEnd":115.645999998378,"proxyStart":-1},"encodedDataLength":-1,"remotePort":80,"mimeType":"text/html","headersText":"HTTP/1.1 200 OK\r\nDate: Tue, 11 Oct 2016 14:08:47 GMT\r\nServer: Apache/2.2.22 (Ubuntu)\r\nAccept-Ranges: bytes\r\nCache-Control: max-age=300\r\nExpires: Tue, 11 Oct 2016 14:13:47 GMT\r\nVary: Accept-Encoding\r\nContent-Encoding: gzip\r\nContent-Length: 1957\r\nKeep-Alive: timeout=4, max=100\r\nConnection: Keep-Alive\r\nContent-Type: text/html\r\n\r\n","securityState":"neutral","requestHeadersText":"GET /teaching/cws/wws/webpage1.html HTTP/1.1\r\nHost: www.york.ac.uk\r\nConnection: keep-alive\r\nUpgrade-Insecure-Requests: 1\r\nUser-Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Safari/537.36\r\nAccept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8\r\nAccept-Encoding: gzip, deflate, sdch\r\nAccept-Language: en-GB,en-US;q=0.8,en;q=0.6\r\n\r\n","url":"http://www.york.ac.uk/teaching/cws/wws/webpage1.html","protocol":"http/1.1","fromDiskCache":false,"fromServiceWorker":false,"requestHeaders":{"Accept":"text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8","Upgrade-Insecure-Requests":"1","Connection":"keep-alive","User-Agent":"Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Safari/537.36","Host":"www.york.ac.uk","Accept-Encoding":"gzip, deflate, sdch","Accept-Language":"en-GB,en-US;q=0.8,en;q=0.6"},"remoteIPAddress":"144.32.128.84","statusText":"OK","connectionId":11,"status":200},"loaderId":"3928.1","type":"Document","timestamp":20226.770012}}}
    ---------- bingo !!!!!!!!!!!!!! returned response for http://www.york.ac.uk/teaching/cws/wws/webpage1.html: 200
    ---------- bingo !!!!!!!!!!!!!! headers: {"Accept-Ranges":"bytes","Keep-Alive":"timeout=4, max=100","Cache-Control":"max-age=300","Server":"Apache/2.2.22 (Ubuntu)","Connection":"Keep-Alive","Content-Encoding":"gzip","Vary":"Accept-Encoding","Expires":"Tue, 11 Oct 2016 14:13:47 GMT","Content-Length":"1957","Date":"Tue, 11 Oct 2016 14:08:47 GMT","Content-Type":"text/html"}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Network.dataReceived","params":{"dataLength":2111,"requestId":"3928.1","encodedDataLength":1460,"timestamp":20226.770425}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Page.frameNavigated","params":{"frame":{"securityOrigin":"http://www.york.ac.uk","loaderId":"3928.1","id":"3928.1","mimeType":"text/html","url":"http://www.york.ac.uk/teaching/cws/wws/webpage1.html"}}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Network.dataReceived","params":{"dataLength":1943,"requestId":"3928.1","encodedDataLength":825,"timestamp":20226.782673}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Network.loadingFinished","params":{"requestId":"3928.1","encodedDataLength":2285,"timestamp":20226.770199}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Page.loadEventFired","params":{"timestamp":20226.799391}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Page.frameStoppedLoading","params":{"frameId":"3928.1"}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Page.domContentEventFired","params":{"timestamp":20226.845769}}}
    {"webview":"3b8eaedb-bd0f-4baa-938d-4aee4039abfe","message":{"method":"Network.requestWillBeSent","params":{"request":{"headers":{"Referer":"http://www.york.ac.uk/teaching/cws/wws/webpage1.html","User-Agent":"Mozilla/5.0 (Windows NT 6.3; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.143 Safari/537.36"},"initialPriority":"High","method":"GET","mixedContentType":"none","url":"http://www.york.ac.uk/favicon.ico"},"frameId":"3928.1","requestId":"3928.2","documentURL":"http://www.york.ac.uk/teaching/cws/wws/webpage1.html","initiator":{"type":"other"},"loaderId":"3928.1","wallTime":1.47619492768527E9,"type":"Other","timestamp":20226.848174}}}

    status code: 200

java + Selenium + Firefox I have finally found the trick for Firefox too. You need to start firefox using MOZ_LOG and MOZ_LOG_FILE environment variables, and log http requests at debug level (4 = PR_LOG_DEBUG) - map.put("MOZ_LOG", "timestamp,sync,nsHttp:4"). Save the log in a temporary file. After that, get the content of the saved log file and parse it for the response code (using some simple regular expressions). First detect the start of the request, identifying its id (nsHttpChannel::BeginConnect [this=000000CED8094000]), then at the second step, find the response code for that request id (nsHttpChannel::ProcessResponse [this=000000CED8094000 httpStatus=200]).

import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.io.FileUtils;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.firefox.FirefoxDriver;
import org.openqa.selenium.firefox.GeckoDriverService;

public class TestFirefoxResponse
{
  public static void main(String[] args)
      throws InterruptedException, IOException
  {
    GeckoDriverService service = null;

    // tell firefox to log http requests
    // at level 4 = PR_LOG_DEBUG: debug messages, notices
    // you could log everything at level 5, but the log file will 
    // be larger. 
    // create a temporary log file that will be parsed for
    // response code
    Map<String, String> map = new HashMap<String, String>();
    map.put("MOZ_LOG", "timestamp,sync,nsHttp:4");
    File tempFile = File.createTempFile("mozLog", ".txt");    
    map.put("MOZ_LOG_FILE", tempFile.getAbsolutePath());      

    GeckoDriverService.Builder builder = new GeckoDriverService.Builder();
    service = builder.usingAnyFreePort()
      .withEnvironment(map)
      .build();

    service.start();      

    WebDriver driver = new FirefoxDriver(service);

    // test 200
     String url = "https://api.ipify.org/?format=text";
    // test 404
    // String url = "https://www.advancedwebranking.com/lsdkjflksdjfldksfj";
    driver.get(url);

    driver.quit();

    String logContent = FileUtils.readFileToString(tempFile);

    ParseLog(logContent, url);
  }

  private static void ParseLog(String logContent, String url) throws MalformedURLException
  {
    // this is how the log looks like when the request starts
    // I have to get the id of the request using a regular expression
    // and use that id later to get the response
    //
    //    2017-11-02 14:14:01.170000 UTC - [Main Thread]: D/nsHttp nsHttpChannel::BeginConnect [this=000000BFF27A5000]
    //    2017-11-02 14:14:01.170000 UTC - [Main Thread]: D/nsHttp host=api.ipify.org port=-1
    //    2017-11-02 14:14:01.170000 UTC - [Main Thread]: D/nsHttp uri=https://api.ipify.org/?format=text
    String pattern = "BeginConnect \\[this=(.*?)\\](?:.*?)uri=(.*?)\\s";

    Pattern p = Pattern.compile(pattern, Pattern.CASE_INSENSITIVE | Pattern.DOTALL);
    Matcher m = p.matcher(logContent);

    String urlID = null;
    while (m.find())
    {
      String id = m.group(1);
      String uri = m.group(2);

      if (uri.equals(url))
      {
        urlID = id;
        break;
      }      
    }

    System.out.println("request id = " + urlID);

    // this is how the response looks like in the log file
    // ProcessResponse [this=000000CED8094000 httpStatus=200]
    // I will use another regular espression to get the httpStatus
    //
    //    2017-11-02 14:45:39.296000 UTC - [Main Thread]: D/nsHttp nsHttpChannel::OnStartRequest [this=000000CED8094000 request=000000CED8014BB0 status=0]
    //    2017-11-02 14:45:39.296000 UTC - [Main Thread]: D/nsHttp nsHttpChannel::ProcessResponse [this=000000CED8094000 httpStatus=200]    

    pattern = "ProcessResponse \\[this=" + urlID + " httpStatus=(.*?)\\]";

    p = Pattern.compile(pattern, Pattern.CASE_INSENSITIVE | Pattern.DOTALL);
    m = p.matcher(logContent);

    if (m.find())
    {
      String responseCode = m.group(1);
      System.out.println("response code found " + responseCode);
    }
    else
    {
      System.out.println("response code not found");
    }
  }
}

The output for this will be

request id = 0000007653D67000 response code found 200

The response headers can also be found in the log file. You can get them if you want.

    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp http response [
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   HTTP/1.1 404 Not Found
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Accept-Ranges: bytes
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Cache-control: no-cache="set-cookie"
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Content-Type: text/html; charset=utf-8
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Date: Thu, 02 Nov 2017 14:54:36 GMT
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   ETag: "7969-55bc076a61e80"
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Last-Modified: Tue, 17 Oct 2017 16:17:46 GMT
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Server: Apache/2.4.23 (Amazon) PHP/5.6.24
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Set-Cookie: AWSELB=5F256FFA816C8E72E13AE0B12A17A3D540582F804C87C5FEE323AF3C9B638FD6260FF473FF64E44926DD26221AAD2E9727FD739483E7E4C31784C7A495796B416146EE83;PATH=/
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Content-Length: 31081
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Connection: keep-alive
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp     OriginalHeaders
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Accept-Ranges: bytes
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Cache-control: no-cache="set-cookie"
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Content-Type: text/html; charset=utf-8
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Date: Thu, 02 Nov 2017 14:54:36 GMT
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   ETag: "7969-55bc076a61e80"
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Last-Modified: Tue, 17 Oct 2017 16:17:46 GMT
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Server: Apache/2.4.23 (Amazon) PHP/5.6.24
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Set-Cookie: AWSELB=5F256FFA816C8E72E13AE0B12A17A3D540582F804C87C5FEE323AF3C9B638FD6260FF473FF64E44926DD26221AAD2E9727FD739483E7E4C31784C7A495796B416146EE83;PATH=/
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Content-Length: 31081
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp   Connection: keep-alive
    2017-11-02 14:54:36.775000 UTC - [Socket Thread]: I/nsHttp ]
    2017-11-02 14:54:36.775000 UTC - [Main Thread]: D/nsHttp nsHttpChannel::OnStartRequest [this=0000008A65D85000 request=0000008A65D1F900 status=0]
    2017-11-02 14:54:36.775000 UTC - [Main Thread]: D/nsHttp nsHttpChannel::ProcessResponse [this=0000008A65D85000 httpStatus=404]

Obtain the Response Code in Any Language (Using JavaScript):

If your Selenium tests run in a modern browser, an easy way to obtain the response code is to send a synchronous XMLHttpRequest* and check the status of the response:

var xhr = new XMLHttpRequest();
xhr.open('GET', 'http://exampleurl.ex', false);
xhr.send(null);

assert(200, xhr.status);

You can use this technique with any programming language by requesting that Selenium execute the script. For example, in Java you can use JavascriptExecutor.executeScript() to send the XMLHttpRequest:

final String GET_RESPONSE_CODE_SCRIPT =
    "var xhr = new XMLHttpRequest();" +
    "xhr.open('GET', arguments[0], false);" +
    "xhr.send(null);" +
    "return xhr.status";
JavascriptExecutor javascriptExecutor = (JavascriptExecutor) webDriver;
Assert.assertEquals(200,
    javascriptExecutor.executeScript(GET_RESPONSE_CODE_SCRIPT, "http://exampleurl.ex"));

* You could send an asynchronous XMLHttpRequest instead, but you would need to wait for it to complete before continuing your test.

Obtain the Response Code in Java:

You can obtain the response code in Java by using URL.openConnection() and HttpURLConnection.getResponseCode():

URL url = new URL("http://exampleurl.ex");
HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection();
httpURLConnection.setRequestMethod("GET");

// You may need to copy over the cookies that Selenium has in order
// to imitate the Selenium user (for example if you are testing a
// website that requires a sign-in).
Set<Cookie> cookies = webDriver.manage().getCookies();
String cookieString = "";

for (Cookie cookie : cookies) {
    cookieString += cookie.getName() + "=" + cookie.getValue() + ";";
}

httpURLConnection.addRequestProperty("Cookie", cookieString);
Assert.assertEquals(200, httpURLConnection.getResponseCode());

This method could probably be generalized to other languages as well but would need to be modified to fit the language's (or library's) API.