通过下面的代码，我已经能够保存cookie，但是一旦关闭应用程序，cookie就会消失。

这是怎么引起的，我该如何解决？

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://");

}

}