How to set cookie in android WebView client

My problem was slightly different, but answer from @Tixeon gave me the key to solve it. I was composing my Cookie and adding it to the WebView request, but I discovered that Android was overriding my Cookie and sending its own Cookie. So first of all, I had to remove all cookies from the array, then compose my own Cookie. This is the sample code:

// Note that my project has minSdkVersion 21, so I can directly use methods only available in Lollipop
private fun loadUrlInWebView(url: String) {
    webView.settings.apply {
        builtInZoomControls = false
        javaScriptEnabled = true
        useWideViewPort = true
        loadWithOverviewMode = true
        setSupportMultipleWindows(false)
    }
    CookieManager.getInstance().apply {
        setAcceptThirdPartyCookies(webView, true) // My minSdkVersion is 21
        removeAllCookies { value ->
            Log.d("Cookies", "Removed all cookies from CookieManager")
        }
    }

    webView.apply {
        isVerticalScrollBarEnabled = true
        isHorizontalScrollBarEnabled = true
        loadUrl(
            url,
            mutableMapOf(
                "Cookie" to "ThisIsMyCookieWithMyValues",
                "Accept" to "*/*",
                "Accept-Encoding" to "gzip, deflate",
                "Cache-Control" to "no-cache",
                "Content-type" to "application/x-www-form-urlencoded"
            )
        )
    }
}

Now the request contains my Cookie and not the default one provided by Android, and my session in WebView is working. Hope this helps someone else

Ohh after several hours, i finally figured it out to get it worked. Firstly CookieSyncManager is deprecated on later version of android since api 21 according to doc. So decided not to use it anymore. Secondly CookieManager is used to store cookie for WebView.

Final code

    CookieManager cookieManager = CookieManager.getInstance();
    cookieManager.setAcceptCookie(true);

    List<Cookie> cookies = WSHelper.cookieStore.getCookies();

    cookieManager.removeAllCookie();

    if (cookies != null) {
        for (Cookie cookie : cookies) {
            if (cookie.getName().contains("session")){
                String cookieString = cookie.getName() + "=" + cookie.getValue() + "; Domain=" + cookie.getDomain();
                cookieManager.setCookie(cookie.getDomain(), cookieString);
                Log.d("CookieUrl",cookieString + " ");
            }
        }
    }
    webView.loadUrl(url);

The key changes to solution is: use cookie.getDomain() instead of explicit domain.

cookieManager.setCookie(cookie.getDomain(), cookieString);

Try this code, after few changes works for me:

public class WebViewActivity extends Activity{
    private SharedPreferences mPreferences;

    String token="";
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.webviewpage);

        mPreferences = getSharedPreferences("CurrentUser", MODE_PRIVATE);

    }

    public void LaunchWebView(View view) {

        WebView myWebView = (WebView) findViewById(R.id.myWebView);
        myWebView.getSettings().setJavaScriptEnabled(true);
        myWebView.getSettings().setSaveFormData(false);

        CookieSyncManager.createInstance(this);
        CookieSyncManager.getInstance().startSync();
        CookieManager cookieManager = CookieManager.getInstance();
        cookieManager.setAcceptCookie(true);
        CookieManager.getInstance().setAcceptThirdPartyCookies(myWebView, true);

        SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(this);
        String token2= mPreferences.getString("auth_token","");

        HashMap<String, String> map = new HashMap<String, String>();
        map.put("x-auth-token", token);

        myWebView.getSettings().setAppCacheEnabled(true);
        myWebView.setWebViewClient(new WebViewClient() {
            public boolean shouldOverrideUrlLoading(WebView view,String url) {
                view.loadUrl(url);
                return true;
            }
        });
        myWebView.loadUrl("YOUR_URL", map);
    }
}