How can I tell HtmlUnit's WebClient to download images and css?

Question

How can I make WebClient download external css stylesheets and image bodies just like a usual web browser does?

Answer 1

source : How to get base64 encoded contents for an ImageReader?

HtmlImage img = (HtmlImage) p.getByXPath("//img").get(3);
ImageReader imageReader = img.getImageReader();
BufferedImage bufferedImage = imageReader.read(0);
String formatName = imageReader.getFormatName();
ByteArrayOutputStream byteaOutput = new ByteArrayOutputStream();
Base64OutputStream base64Output = new base64OutputStream(byteaOutput);
ImageIO.write(bufferedImage, formatName, base64output);
String base64 = new String(byteaOutput.toByteArray());

Answer 2

Here's what I came up with:

public InputStream httpGetLowLevel(URL url) throws IOException
{
    WebRequest wrq=new WebRequest(url);

    ProxyConfig config =webClient.getProxyConfig();

    //set request webproxy
    wrq.setProxyHost(config.getProxyHost());
    wrq.setProxyPort(config.getProxyPort());
    wrq.setCredentials(webClient.getCredentialsProvider().getCredentials(new AuthScope(config.getProxyHost(), config.getProxyPort())));
    for(Cookie c:webClient.getCookieManager().getCookies(url)){
        wrq.setAdditionalHeader("Cookie", c.toString());            
    }           
    WebResponse wr= webClient.getWebConnection().getResponse(wrq);
    return wr.getContentAsStream();
}

My tests show, that it does support proxys and that it not only carries cookies from WebClient, but also if server sends new cookies during the response, the WebClient will eat those cookies

Answer 3

HtmlUnit does not download CSS or images. They are useless to a headless browser...

Last I heard of it is here, but the ticket is marked private: http://osdir.com/ml/java.htmlunit.devel/2007-01/msg00021.html

Answer 4

What I'm doing right now is:

public static final HashMap<String, String> acceptTypes = new HashMap<String, String>(){{
        put("html", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8");
        put("img", "image/png,image/*;q=0.8,*/*;q=0.5");
        put("script", "*/*");
        put("style", "text/css,*/*;q=0.1");
    }};

protected void downloadCssAndImages(HtmlPage page) {
        String xPathExpression = "//*[name() = 'img' or name() = 'link' and @type = 'text/css']";
        List<?> resultList = page.getByXPath(xPathExpression);

        Iterator<?> i = resultList.iterator();
        while (i.hasNext()) {
            try {
                HtmlElement el = (HtmlElement) i.next();

                String path = el.getAttribute("src").equals("")?el.getAttribute("href"):el.getAttribute("src");
                if (path == null || path.equals("")) continue;

                URL url = page.getFullyQualifiedUrl(path);

                WebRequestSettings wrs = new WebRequestSettings(url);
                wrs.setAdditionalHeader("Referer", page.getWebResponse().getRequestSettings().getUrl().toString());

                client.addRequestHeader("Accept", acceptTypes.get(el.getTagName().toLowerCase()));
                client.getPage(wrs);
            } catch (Exception e) {}
        }



client.removeRequestHeader("Accept");
}