Pass cookies from HttpURLConnection (java.net.CookieManager) to WebView (android.webkit.CookieManager)

Question

I've seen answers about how this should work with the old DefaultHttpClient but there's not a good example for HttpURLConnection

I'm using HttpURLConnection to make requests to a web application. At the start of the my Android application, I use CookieHandler.setDefault(new CookieManager()) to automatically deal with the session cookies, and this is working fine.

At some point after the login, I want to show live pages from the web application to the user with a WebView instead of downloading data behind the scenes with HttpURLConnection. However, I want to use the same session I established earlier to prevent the user from having to login again.

How do I copy the cookies from java.net.CookieManager used by HttpURLConnection to android.webkit.CookieManager used by WebView so I can share the session?

Answer 1

I would like to suggest a completely different approach to your problem. Instead of copying cookies from one place to another (manual sync), let's make HttpURLConnection and WebViews use the same cookie storage.

This completely eliminates the need for sync. Any cookie updated in any one of them, will be immediately and automatically reflected in the other.

To do this, create your own implementation of java.net.CookieManager which forwards all requests to the WebViews' webkit android.webkit.CookieManager.

Implementation:

import java.io.IOException;
import java.net.CookieManager;
import java.net.CookiePolicy;
import java.net.CookieStore;
import java.net.URI;
import java.util.Arrays;
import java.util.List;
import java.util.Map;

public class WebkitCookieManagerProxy extends CookieManager 
{
    private android.webkit.CookieManager webkitCookieManager;

    public WebkitCookieManagerProxy()
    {
        this(null, null);
    }

    WebkitCookieManagerProxy(CookieStore store, CookiePolicy cookiePolicy)
    {
        super(null, cookiePolicy);

        this.webkitCookieManager = android.webkit.CookieManager.getInstance();
    }

    @Override
    public void put(URI uri, Map<String, List<String>> responseHeaders) throws IOException 
    {
        // make sure our args are valid
        if ((uri == null) || (responseHeaders == null)) return;

        // save our url once
        String url = uri.toString();

        // go over the headers
        for (String headerKey : responseHeaders.keySet()) 
        {
            // ignore headers which aren't cookie related
            if ((headerKey == null) || !(headerKey.equalsIgnoreCase("Set-Cookie2") || headerKey.equalsIgnoreCase("Set-Cookie"))) continue;

            // process each of the headers
            for (String headerValue : responseHeaders.get(headerKey))
            {
                this.webkitCookieManager.setCookie(url, headerValue);
            }
        }
    }

    @Override
    public Map<String, List<String>> get(URI uri, Map<String, List<String>> requestHeaders) throws IOException 
    {
        // make sure our args are valid
        if ((uri == null) || (requestHeaders == null)) throw new IllegalArgumentException("Argument is null");

        // save our url once
        String url = uri.toString();

        // prepare our response
        Map<String, List<String>> res = new java.util.HashMap<String, List<String>>();

        // get the cookie
        String cookie = this.webkitCookieManager.getCookie(url);

        // return it
        if (cookie != null) res.put("Cookie", Arrays.asList(cookie));
        return res;
    }

    @Override
    public CookieStore getCookieStore() 
    {
        // we don't want anyone to work with this cookie store directly
        throw new UnsupportedOperationException();
    }
}

and finally use it by doing this on your application initialization:

android.webkit.CookieSyncManager.createInstance(appContext);
// unrelated, just make sure cookies are generally allowed
android.webkit.CookieManager.getInstance().setAcceptCookie(true);

// magic starts here
WebkitCookieManagerProxy coreCookieManager = new WebkitCookieManagerProxy(null, java.net.CookiePolicy.ACCEPT_ALL);
java.net.CookieHandler.setDefault(coreCookieManager);