java使用htmlunit爬虫模拟登陆（WebClient ，HtmlTextInput ，HtmlSubmitInput click

public static void main(String[] args)
        throws FailingHttpStatusCodeException, MalformedURLException,
        IOException {

        WebClient wc = initWebClient(null);

        HtmlPage page = wc.getPage(Constants.START_PAGE);

        HtmlTextInput userInput = (HtmlTextInput) page
            .getElementById(Constants.INPUT_USERNAME_ID);
        userInput.setText(Constants.USERNAME_VALUE);

        HtmlPasswordInput passwordInput = (HtmlPasswordInput) page
            .getElementById(Constants.INPUT_PASSWORD_ID);
        passwordInput.setText(Constants.PASSWORD_VALUE);

        // get submit button
        HtmlSubmitInput submitButton = (HtmlSubmitInput) page
            .getElementById(Constants.SUBMIT_BUTTON_ID);

        HtmlPage afterLoginPage = submitButton.click();

       Set<Cookie> cookies = wc.getCookieManager().getCookies();
     
       // for every thread I create new WebClient
       for(threads loop){
           WebClient wc2 = initWebClient(cookies);
       }
    }

    private static WebClient initWebClient(Set<Cookie> cookies) {
       WebClient wc = new WebClient(BrowserVersion.CHROME);
       wc.getCookieManager().setCookiesEnabled(true);
       wc.getOptions().setJavaScriptEnabled(false);
       wc.getOptions().setThrowExceptionOnScriptError(false);

       if (cookies != null) {
          Iterator<Cookie> i = cookies.iterator();
          while (i.hasNext()) {
              wc.getCookieManager().addCookie(i.next());
          }
        }

        return wc;
   }