ClassCastException UnexpectedPage cannot be cast to HtmlPage #303

try (final WebClient webClient = new WebClient(BrowserVersion.FIREFOX)) {			 
   java.util.logging.Logger.getLogger("com.gargoylesoftware").setLevel(java.util.logging.Level.OFF);
				webClient.getCache().clear();
				webClient.getOptions().setCssEnabled(true);
				webClient.getOptions().setJavaScriptEnabled(true);
				webClient.setAjaxController(new NicelyResynchronizingAjaxController());
				webClient.getOptions().setThrowExceptionOnScriptError(true);

				webClient.waitForBackgroundJavaScriptStartingBefore(10_000);

				URL thisUrl = new URL("http://localhost:9080/Navigator/DispatcherServlet/login");
				WebRequest requestSettings = new WebRequest(thisUrl, HttpMethod.POST);
			    requestSettings.setAdditionalHeader("Content-Type", "application/json");
			    requestSettings.setRequestBody("{'name':'abc123', 'password':'xxxyyyzz'}");
			    System.out.println("request:"+requestSettings.toString());
				**Page redirectPage = webClient.getPage(requestSettings);** 
// above line will get the classCastException if class HtmlPage is used instead of Page
				
				WebResponse response = redirectPage.getWebResponse();
				System.out.println("responseHeaders:"+response.getResponseHeaders());
				**System.out.println("PAGE"+(HtmlPage)redirectPage).asText());**. // Error in Eclipse: Cannot invoke "asText" on the primitive type void

232				HtmlPage htmlPage = (HtmlPage) redirectPage;	 // runtime error

				String content = response.getContentAsString();
				System.out.println("content:"+content);
				
				DomElement enterButton = htmlPage.getElementById("loginbutton");
				
				DomElement usernameField = htmlPage.getElementById("loginUsername");				
				DomElement passwordField = htmlPage.getElementById("password");

				usernameField.setAttribute("value", m_userProfile);
				passwordField.setAttribute("value", m_userPW);
				
				Page loggedInPage = enterButton.click();
				webClient.waitForBackgroundJavaScript(60000);
				
				boolean hasPage = ((HtmlPage) loggedInPage).asText().contains("IBM Navigator for i");
				System.out.println("@new page:");
				 System.out.println( ((HtmlPage)loggedInPage).asText());
				System.out.println("@end page");