How to save a cookie in an Android webview forever?

问题

With my code below, I have been able to save a cookie, but as soon as I close the application the cookie disappears.

How is this caused and how can I solve it?

package com.jkjljkj

import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.webkit.CookieSyncManager;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;

public class Activity extends Activity {

    /** Called when the activity is first created. */

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        CookieSyncManager.createInstance(getBaseContext());

        // Let's display the progress in the activity title bar, like the
        // browser app does.


        getWindow().requestFeature(Window.FEATURE_PROGRESS);

        WebView webview = new WebView(this);
        setContentView(webview);


        webview.getSettings().setJavaScriptEnabled(true);

        final Activity activity = this;
        webview.setWebChromeClient(new WebChromeClient() {
        public void onProgressChanged(WebView view, int progress) {
             // Activities and WebViews measure progress with different scales.
             // The progress meter will automatically disappear when we reach 100%
             activity.setProgress(progress * 1000);
        }
      });

      webview.setWebViewClient(new WebViewClient() {

         public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
              //Users will be notified in case there's an error (i.e. no internet connection)
              Toast.makeText(activity, "Oh no! " + description, Toast.LENGTH_SHORT).show();
         }
      });

      CookieSyncManager.getInstance().startSync();
      CookieSyncManager.getInstance().sync();

     //This will load the webpage that we want to see
      webview.loadUrl("http://");

   }
}

回答1:

You have to tell the CookieSyncManager to sync after it has loaded the page in question. In your sample code, the onCreate method executes completely before the WebView tries to load the page, so the sync process (which happens asynchronously) will probably complete before the page is loaded.

Instead, tell the CookieSyncManager to sync onPageFinished in the WebViewClient. That should get you what you want.

The CookieSyncManager Documentation is a good read for how to do this properly.

Here is how you could set up your WebViewClient implementation to do this for you:

webview.setWebViewClient(new WebViewClient() {
    public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
        //Users will be notified in case there's an error (i.e. no internet connection)
        Toast.makeText(activity, "Oh no! " + description, Toast.LENGTH_SHORT).show();
    }

    public void onPageFinished(WebView view, String url) {
        CookieSyncManager.getInstance().sync();
    }
);

You would not need to tell the CookieSyncManager to sync elsewhere with this in place. I haven't tested this, so let me know if it works.

回答2:

.sync() is to force a imediate sync ,and must be called after page load cause it sync RAM with cache , so cookie must be in ram before calling it .

System automatically sync it every 5 mintues if you use this scheme

onCreate: 
CookieSyncManager.createInstance(context)

onResume:
CookieSyncManager.getInstance().startSync()

onPause:
CookieSyncManager.getInstance().stopSync()

I think you did not waited 5 mintues so system save cookie.

回答3:

For those who are facing Problems with CookieManager class to make cookie persist even after closing the app, they should try the flush() function of CookieManager.

Please note that i haven't tried this, so if it works then please let me know too.

According to android documentation

void flush()

Ensures all cookies currently accessible through the getCookie API are written to persistent storage. This call will block the caller until it is done and may perform I/O.

Also in CookieSyncManager documnentation it is written that:

This class was deprecated in API level 21. The WebView now automatically syncs cookies as necessary. You no longer need to create or use the CookieSyncManager. To manually force a sync you can use the CookieManager method flush() which is a synchronous replacement for sync(). CookieSyncManger link

来源：https://stackoverflow.com/questions/8390156/how-to-save-a-cookie-in-an-android-webview-forever

标签

java

android

webview

cookiestore