Selenium throws exception on isTextPresent() on custom error page

In a selenium test, I open a page to which I don't have rights, and I want to verify that error page is displayed instead of the opened one.

Check if this is error page is simple:

Assert.assertTrue(selenium.isTextPresent("HTTP Status 403"));

Now I changed default JBoss error page to custom one, by <error-page> tag in web.xml. After this, selenium doesn't work. It throws exception from isTextPresent(). Of course text on the page changed too, but it doesn't matter here.

Stacktrace is:

com.thoughtworks.selenium.SeleniumException: ERROR: Command execution failure. Please search the forum at http://clearspace.openqa.org for error details from the log window.  The error message is: doc.style is undefined
at com.thoughtworks.selenium.HttpCommandProcessor.throwAssertionFailureExceptionOrError(HttpCommandProcessor.java:97)
at com.thoughtworks.selenium.HttpCommandProcessor.doCommand(HttpCommandProcessor.java:91)
at pl.softwaremill.common.test.web.selenium.screenshots.ScreenshotHttpCommandProcessor.doCommand(ScreenshotHttpCommandProcessor.java:31)
at com.thoughtworks.selenium.DefaultSelenium.captureEntirePageScreenshot(DefaultSelenium.java:679)
at pl.softwaremill.common.test.web.selenium.AbstractSeleniumTest.captureScreenshot(AbstractSeleniumTest.java:166)
at pl.softwaremill.common.test.web.selenium.AbstractSeleniumTest$1.doScreenshot(AbstractSeleniumTest.java:95)
... 27 more
com.thoughtworks.selenium.SeleniumException: ERROR: Couldn't access document.body.  Is this HTML page fully loaded?
at com.thoughtworks.selenium.HttpCommandProcessor.throwAssertionFailureExceptionOrError(HttpCommandProcessor.java:97)
at com.thoughtworks.selenium.HttpCommandProcessor.doCommand(HttpCommandProcessor.java:91)
at com.thoughtworks.selenium.HttpCommandProcessor.getString(HttpCommandProcessor.java:262)
at com.thoughtworks.selenium.HttpCommandProcessor.getBoolean(HttpCommandProcessor.java:335)
at pl.softwaremill.common.test.web.selenium.screenshots.ScreenshotHttpCommandProcessor.getBoolean(ScreenshotHttpCommandProcessor.java:92)
at com.thoughtworks.selenium.DefaultSelenium.isTextPresent(DefaultSelenium.java:499)
at za.co.fnb.com开发者_如何学运维mercial.dms.uitests.view.debtor.DebtorInsuranceAnnexurePage.<init>(DebtorInsuranceAnnexurePage.java:18)
at za.co.fnb.commercial.dms.uitests.view.debtor.UploadDebtorFilesPage.submit(UploadDebtorFilesPage.java:45)
at za.co.fnb.commercial.dms.uitests.view.debtor.UploadDebtorFilesSeleniumTest.shouldStoreFileEvenIfParseFails(UploadDebtorFilesSeleniumTest.java:145)

pl.softwaremill.common.test.web.selenium.screenshots.ScreenshotHttpCommandProcessor just delegates work to com.thoughtworks.selenium.HttpCommandProcessor

Because error message says "Is this HTML page fully loaded?" you can think the page is not fully loaded, but it is. I tried it in debug, giving some time for page to load, and it was loaded, yet still this error occured.

Actually i have the same exception and search the reason first i track the stacktrace and debug the selenium code these are my learning;

I used selenium remote server

Selenium Version:

 <dependency>
            <groupId>org.seleniumhq.selenium</groupId>
            <artifactId>selenium-java</artifactId>
            <version>2.39.0</version>
            <scope>test</scope>
        </dependency>

These are call hierarchy of selenium.isTextPresent()

Call Hierarchy

public boolean isTextPresent(String pattern) {
    return commandProcessor.getBoolean("isTextPresent", new String[] {pattern,});
  }

public boolean getBoolean(String commandName, String[] args) {
    String result = getString(commandName, args);
    ..........
..............
  }

 public String getString(String commandName, String[] args) {
    String result = doCommand(commandName, args);
    ..........
    ..............
  }
 public String doCommand(String commandName, String[] args) {
    DefaultRemoteCommand command = new DefaultRemoteCommand(commandName, args);
    String result = executeCommandOnServlet(command.getCommandURLString());
    ..........
   ..............
  }


/** Sends the specified command string to the bridge servlet */
  public String executeCommandOnServlet(String command) {
    try {
      return getCommandResponseAsString(command);
    } catch (IOException e) {
     ..........
       ..............
    }
  }

My Understanding

Until here there is only a call hierarchy actual implementer method is getCommandResponseAsString(String command) so it is hard to get exact(actually i mean stabile) result from debug of this method, because when check the implementation it seems method check the response code HttpURLConnection.HTTP_OK(its value is 200) if the response code is OK, it returns the executed string, but some time consuming cases it is not and throw throwAssertionFailureExceptionOrError(uc.getResponseMessage());

Implementer Method

protected String getCommandResponseAsString(String command) throws IOException {
    String responseString = null;
    int responsecode = HttpURLConnection.HTTP_MOVED_PERM;
    HttpURLConnection uc = null;
    Writer wr = null;
    Reader rdr = null;
    while (responsecode == HttpURLConnection.HTTP_MOVED_PERM) {
      URL result = new URL(pathToServlet);
      String body = buildCommandBody(command);
      try {
        uc = getHttpUrlConnection(result);
        uc.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=utf-8");
        uc.setInstanceFollowRedirects(false);
        uc.setDoOutput(true);
        wr = getOutputStreamWriter(uc);
        wr.write(body);
        wr.flush();
        responsecode = getResponseCode(uc);
        if (responsecode == HttpURLConnection.HTTP_MOVED_PERM) {
          pathToServlet = uc.getHeaderField("Location");
        } else if (responsecode != HttpURLConnection.HTTP_OK) {
          throwAssertionFailureExceptionOrError(uc.getResponseMessage());
        } else {
          rdr = getInputStreamReader(uc);
          responseString = stringContentsOfInputStream(rdr);
        }
      } finally {
        closeResources(uc, wr, rdr);
      }
    }
    return responseString;
  }

Dirty Solution

I try to explain the reason at above, so until i find an ideal way i go on my testing with Thread.sleep() method or selenium.setSpeed(1000) method usage before selenium.isTextPresent() method.