Tôi có một ứng dụng Android chỉ đơn giản là chứa một trang web. Tôi muốn ứng dụng lưu vào bộ nhớ cache các trang của trang web để sử dụng ngoại tuyến.Android WebView không tải trang thứ hai từ bộ nhớ cache
Tôi đang thực hiện một thử nghiệm đơn giản để xem bộ nhớ cache có đang hoạt động hay không nhưng tiếc là không tải được trang tôi đã tải trước đó ở chế độ trực tuyến, khi ngoại tuyến. Để làm cho mọi thứ rõ ràng hơn, tôi tải 2 trang sau khi ở chế độ trực tuyến.
webView.loadUrl("http://www.bmimobile.co.uk/why-bmi.php", getHeaders());
webView.loadUrl("http://www.bmimobile.co.uk/", getHeaders());
.
Tôi hy vọng rằng trang "why-bmi.php" được tải vào bộ nhớ cache cũng như trang tiếp theo http://www.bmimobile.co.uk/. Trang thứ hai có một liên kết trên trang liên quan đến trang đầu tiên. Nếu sau đó tôi ra khỏi ứng dụng và tắt bộ điều hợp mạng rồi quay lại ứng dụng, trang "http://www.bmimobile.co.uk/" KHÔNG hiển thị nhưng khi tôi nhấp vào liên kết "why-bmi" mà trang KHÔNG hiển thị. Tôi hiển thị tin nhắn bánh mì nướng ngắn nói "lỗi tải trang".
Bất cứ ai có thể cho tôi biết lý do tại sao webview không lưu trong bộ nhớ cache trang đã tải để sử dụng ngoại tuyến sau này?
Đây là hoạt động chính và tôi đã mở rộng đối tượng Application xác định appcachepath.
Cảm ơn trước
Matt
package uk.bmi.mobile;
import java.io.File;
import java.util.HashMap;
import java.util.Map;
import android.app.Activity;
import android.content.Context;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.util.Log;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class MainActivity extends Activity {
private WebView webView;
private static final String TAG = MainActivity.class.getSimpleName();
ApplicationExt bmiAppObj;
//instruct server to set it's headers to make resources cachable
private Map<String, String> getHeaders() {
Map<String, String> headers = new HashMap<String, String>();
headers.put("IS_ALEX_APP", "1");
return headers;
}
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.e(TAG, "in onCreate in mainactivity");
} //end of oncreate
private boolean isNetworkAvailable() {
ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetworkInfo = connectivityManager.getActiveNetworkInfo();
return activeNetworkInfo != null;
}
@Override
protected void onResume() {
super.onResume();
Log.e(TAG, "in onResume in mainactivity");
webView = (WebView)findViewById(R.id.webView1);
bmiAppObj = (ApplicationExt)getApplication();
if(isNetworkAvailable() == true){
webView.getSettings().setSupportZoom(true);
webView.getSettings().setBuiltInZoomControls(true);
webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
webView.setScrollbarFadingEnabled(true);
webView.getSettings().setLoadsImagesAutomatically(true);
webView.getSettings().setDomStorageEnabled(true);
webView.getSettings().setAppCacheEnabled(true);
// Set cache size to 8 mb by default. should be more than enough
webView.getSettings().setAppCacheMaxSize(1024*1024*8);
// This next one is crazy. It's the DEFAULT location for your app's cache
// But it didn't work for me without this line.
// UPDATE: no hardcoded path. Thanks to Kevin Hawkins
String appCachePath = getApplicationContext().getCacheDir().getAbsolutePath();
Log.e(TAG, "appCachePath = " + appCachePath);
webView.getSettings().setAppCachePath(appCachePath);
webView.getSettings().setAllowFileAccess(true);
webView.getSettings().setJavaScriptEnabled(true);
// Load the URLs inside the WebView, not in the external web browser
webView.setWebViewClient(new WebViewClient());
webView.getSettings().setCacheMode(WebSettings.LOAD_DEFAULT);
webView.loadUrl("http://www.bmimobile.co.uk/why-bmi.php", getHeaders());
webView.loadUrl("http://www.bmimobile.co.uk/", getHeaders());
}else{
webView.getSettings().setSupportZoom(true);
webView.getSettings().setBuiltInZoomControls(true);
webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
webView.setScrollbarFadingEnabled(true);
webView.getSettings().setLoadsImagesAutomatically(true);
webView.getSettings().setDomStorageEnabled(true);
webView.getSettings().setAppCacheEnabled(true);
// Set cache size to 8 mb by default. should be more than enough
webView.getSettings().setAppCacheMaxSize(1024*1024*8);
// This next one is crazy. It's the DEFAULT location for your app's cache
// But it didn't work for me without this line.
// UPDATE: no hardcoded path. Thanks to Kevin Hawkins
String appCachePath = getApplicationContext().getCacheDir().getAbsolutePath();
Log.e(TAG, "appCachePath = " + appCachePath);
webView.getSettings().setAppCachePath(appCachePath);
webView.getSettings().setAllowFileAccess(true);
webView.getSettings().setJavaScriptEnabled(true);
// Load the URLs inside the WebView, not in the external web browser
webView.setWebViewClient(new WebViewClient());
webView.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ONLY);
webView.loadUrl("http://www.bmimobile.co.uk/", getHeaders());
}
}
@Override
public File getCacheDir()
{
// NOTE: this method is used in Android 2.1
Log.e(TAG, "getcachedir");
return getApplicationContext().getCacheDir();
}
@Override
protected void onSaveInstanceState(Bundle outState)
{
super.onSaveInstanceState(outState);
// Save the state of the WebView
webView.saveState(outState);
}
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState)
{
super.onRestoreInstanceState(savedInstanceState);
// Restore the state of the WebView
webView.restoreState(savedInstanceState);
}
}//end of mainActivity
.
package uk.bmi.mobile;
import java.io.File;
import android.app.Application;
import android.os.Environment;
import android.util.Log;
public class ApplicationExt extends Application
{
private static final String TAG = ApplicationExt.class.getSimpleName();
// NOTE: the content of this path will be deleted
// when the application is uninstalled (Android 2.2 and higher)
protected File extStorageAppBasePath;
protected File extStorageAppCachePath;
Webservice webservice;
BmiDB bmiDb;
@Override
public void onCreate()
{
super.onCreate();
Log.e(TAG, "inside appext");
webservice = new Webservice(this);
bmiDb = new BmiDB(this);
// Check if the external storage is writeable
if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState()))
{
// Retrieve the base path for the application in the external storage
File externalStorageDir = Environment.getExternalStorageDirectory();
if (externalStorageDir != null)
{
// {SD_PATH}/Android/data/com.devahead.androidwebviewcacheonsd
extStorageAppBasePath = new File(externalStorageDir.getAbsolutePath() +
File.separator + "Android" + File.separator + "data" +
File.separator + getPackageName());
}
if (extStorageAppBasePath != null)
{
// {SD_PATH}/Android/data/com.devahead.androidwebviewcacheonsd/cache
extStorageAppCachePath = new File(extStorageAppBasePath.getAbsolutePath() +
File.separator + "cache");
boolean isCachePathAvailable = true;
if (!extStorageAppCachePath.exists())
{
// Create the cache path on the external storage
isCachePathAvailable = extStorageAppCachePath.mkdirs();
}
if (!isCachePathAvailable)
{
// Unable to create the cache path
extStorageAppCachePath = null;
}
}
}
}//end of onCreate
@Override
public File getCacheDir()
{
// NOTE: this method is used in Android 2.2 and higher
if (extStorageAppCachePath != null)
{
// Use the external storage for the cache
Log.e(TAG, "extStorageAppCachePath = " + extStorageAppCachePath);
return extStorageAppCachePath;
}
else
{
// /data/data/com.devahead.androidwebviewcacheonsd/cache
return super.getCacheDir();
}
}
}
.Đây là khai thác gỗ khi ứng dụng được đầu tiên nạp trong chế độ trực tuyến
02-16 08:38:52.744: I/NONPRIME(8871): <CallBackProxy> Send to WebViewClient.
02-16 08:38:56.314: D/skia(8871): ----- started: [1 325] http://www.bmimobile.co.uk/images/mobile/bg-index.png
02-16 08:38:56.499: D/skia(8871): ----- started: [1 64] http://www.bmimobile.co.uk/CubeCore/modules/cubeMobile/images/bg-black-bar.png
02-16 08:38:56.509: D/skia(8871): ----- started: [26 20] http://www.bmimobile.co.uk/images/mobile/home-icon.png
02-16 08:38:56.529: D/skia(8871): ----- started: [275 189] http://www.bmimobile.co.uk/images/mobile/home-img.png
02-16 08:38:56.549: D/skia(8871): ----- started: [320 450] http://www.bmimobile.co.uk/images/mobile/welcome/bg-welcome.jpg
02-16 08:38:56.554: D/skia(8871): ----- started: [270 38] http://www.bmimobile.co.uk/images/mobile/welcome/next.png
02-16 08:38:56.584: D/skia(8871): ----- started: [16 17] http://www.bmimobile.co.uk/images/mobile/why.png
02-16 08:38:56.584: D/skia(8871): ----- started: [18 17] http://www.bmimobile.co.uk/images/mobile/services.png
02-16 08:38:56.584: D/skia(8871): ----- started: [20 15] http://www.bmimobile.co.uk/images/mobile/visit.png
02-16 08:38:56.589: D/skia(8871): ----- started: [20 15] http://www.bmimobile.co.uk/images/mobile/consultants.png
02-16 08:38:56.589: D/skia(8871): ----- started: [13 19] http://www.bmimobile.co.uk/images/mobile/contact.png
.
Đây là lần đăng nhập khi tôi thoát khỏi ứng dụng đã tắt bộ điều hợp mạng sau đó quay lại ứng dụng ở chế độ ngoại tuyến.
02-16 08:41:37.799: E/MainActivity(8871): in onResume in mainactivity
02-16 08:41:37.804: E/ApplicationExt(8871): extStorageAppCachePath = /storage/sdcard0/Android/data/uk.bmi.mobile/cache
02-16 08:41:37.804: E/MainActivity(8871): appCachePath = /storage/sdcard0/Android/data/uk.bmi.mobile/cache
02-16 08:41:37.834: W/dalvikvm(8871): disableGcForExternalAlloc: false
[edit1] Trên thực tế về kiểm tra chặt chẽ hơn của khai thác gỗ, nó dường như đã thay đổi khi nạp trong chế độ trực tuyến. dưới đây là logcat trong chế độ omline. Dường như có sự cố với bộ nhớ cache.
02-19 15:16:10.497: E/ApplicationExt(5467): inside appext
02-19 15:16:10.687: E/ApplicationExt(5467): extStorageAppCachePath = /storage/sdcard0/Android/data/uk.bmi.mobile/cache
02-19 15:16:10.722: E/MainActivity(5467): in onCreate in mainactivity
02-19 15:16:10.727: E/MainActivity(5467): in onResume in mainactivity
02-19 15:16:10.737: E/ApplicationExt(5467): extStorageAppCachePath = /storage/sdcard0/Android/data/uk.bmi.mobile/cache
02-19 15:16:10.737: E/MainActivity(5467): appCachePath = /storage/sdcard0/Android/data/uk.bmi.mobile/cache
02-19 15:16:10.792: E/(5467): file /data/data/com.nvidia.NvCPLSvc/files/driverlist.txt: not found!
02-19 15:16:10.792: I/(5467): Attempting to load EGL implementation /system/lib//egl/libEGL_tegra_impl
02-19 15:16:10.807: I/(5467): Loaded EGL implementation /system/lib//egl/libEGL_tegra_impl
02-19 15:16:10.842: I/(5467): Loading GLESv2 implementation /system/lib//egl/libGLESv2_tegra_impl
02-19 15:16:10.882: E/SQLiteLog(5467): (1) no such table: CacheGroups
02-19 15:16:10.882: D/WebKit(5467): ERROR:
02-19 15:16:10.882: D/WebKit(5467): Application Cache Storage: failed to execute statement "DELETE FROM CacheGroups" error "no such table: CacheGroups"
02-19 15:16:10.882: D/WebKit(5467): external/webkit/Source/WebCore/loader/appcache/ApplicationCacheStorage.cpp(558) : bool WebCore::ApplicationCacheStorage::executeSQLCommand(const WTF::String&)
02-19 15:16:10.882: E/SQLiteLog(5467): (1) no such table: Caches
02-19 15:16:10.882: D/WebKit(5467): ERROR:
02-19 15:16:10.882: D/WebKit(5467): Application Cache Storage: failed to execute statement "DELETE FROM Caches" error "no such table: Caches"
02-19 15:16:10.882: D/WebKit(5467): external/webkit/Source/WebCore/loader/appcache/ApplicationCacheStorage.cpp(558) : bool WebCore::ApplicationCacheStorage::executeSQLCommand(const WTF::String&)
02-19 15:16:10.882: E/SQLiteLog(5467): (1) no such table: Origins
02-19 15:16:10.882: D/WebKit(5467): ERROR:
02-19 15:16:10.882: D/WebKit(5467): Application Cache Storage: failed to execute statement "DELETE FROM Origins" error "no such table: Origins"
02-19 15:16:10.882: D/WebKit(5467): external/webkit/Source/WebCore/loader/appcache/ApplicationCacheStorage.cpp(558) : bool WebCore::ApplicationCacheStorage::executeSQLCommand(const WTF::String&)
02-19 15:16:10.882: E/SQLiteLog(5467): (1) no such table: DeletedCacheResources
02-19 15:16:10.992: E/ApplicationExt(5467): extStorageAppCachePath = /storage/sdcard0/Android/data/uk.bmi.mobile/cache
02-19 15:16:11.022: W/dalvikvm(5467): disableGcForExternalAlloc: false
02-19 15:16:13.787: I/NONPRIME(5467): <CallBackProxy> Send to WebViewClient.
02-19 15:16:21.427: D/skia(5467): ----- started: [1 325] http://www.bmimobile.co.uk/images/mobile/bg-index.png
02-19 15:16:21.517: D/skia(5467): ----- started: [1 64] http://www.bmimobile.co.uk/CubeCore/modules/cubeMobile/images/bg-black-bar.png
02-19 15:16:21.542: D/skia(5467): ----- started: [26 20] http://www.bmimobile.co.uk/images/mobile/home-icon.png
02-19 15:16:21.577: D/skia(5467): ----- started: [275 189] http://www.bmimobile.co.uk/images/mobile/home-img.png
02-19 15:16:21.597: D/skia(5467): ----- started: [270 38] http://www.bmimobile.co.uk/images/mobile/welcome/next.png
02-19 15:16:21.677: D/skia(5467): ----- started: [16 17] http://www.bmimobile.co.uk/images/mobile/why.png
02-19 15:16:21.677: D/skia(5467): ----- started: [20 15] http://www.bmimobile.co.uk/images/mobile/visit.png
02-19 15:16:21.677: D/skia(5467): ----- started: [18 17] http://www.bmimobile.co.uk/images/mobile/services.png
02-19 15:16:21.687: D/skia(5467): ----- started: [20 15] http://www.bmimobile.co.uk/images/mobile/consultants.png
02-19 15:16:21.687: D/skia(5467): ----- started: [13 19] http://www.bmimobile.co.uk/images/mobile/contact.png
02-19 15:16:21.692: D/skia(5467): ----- started: [320 450] http://www.bmimobile.co.uk/images/mobile/welcome/bg-welcome.jpg
.
[ghi chú] nếu tôi nhấp vào nút Why-bmi khi ở chế độ trực tuyến sau đó thoát khỏi ứng dụng, tắt bộ điều hợp rồi nhấp vào nút why-bmi một lần nữa, nó sẽ hiển thị thông báo "error loading page" .
Nếu tôi thay đổi thành các url sau, trang SO của tôi được hiển thị. Nếu tôi nhấp vào liên kết đến trang tiền thưởng của tôi (trang này), sau đó đi ngoại tuyến, trang SO được hiển thị như bạn mong đợi nhưng nếu bạn nhấp vào liên kết tiền thưởng trong chế độ ngoại tuyến thì nó sẽ hiển thị. vì vậy có sự khác biệt giữa trang SO và trang web bmi.
if(isNetworkAvailable() == true){
webView.getSettings().setSupportZoom(true);
webView.getSettings().setBuiltInZoomControls(true);
webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
webView.setScrollbarFadingEnabled(true);
webView.getSettings().setLoadsImagesAutomatically(true);
webView.getSettings().setDomStorageEnabled(true);
webView.getSettings().setAppCacheEnabled(true);
// Set cache size to 8 mb by default. should be more than enough
webView.getSettings().setAppCacheMaxSize(1024*1024*8);
// This next one is crazy. It's the DEFAULT location for your app's cache
// But it didn't work for me without this line.
// UPDATE: no hardcoded path. Thanks to Kevin Hawkins
String appCachePath = getApplicationContext().getCacheDir().getAbsolutePath();
Log.e(TAG, "appCachePath = " + appCachePath);
webView.getSettings().setAppCachePath(appCachePath);
webView.getSettings().setAllowFileAccess(true);
webView.getSettings().setJavaScriptEnabled(true);
// Load the URLs inside the WebView, not in the external web browser
webView.setWebViewClient(new WebViewClient());
webView.getSettings().setCacheMode(WebSettings.LOAD_DEFAULT);
//webView.loadUrl("http://www.bmimobile.co.uk/why-bmi.php", getHeaders());
//webView.loadUrl("http://www.bmimobile.co.uk/", getHeaders());
webView.loadUrl("http://stackoverflow.com/users/532462/turtleboy?tab=bounties");
webView.loadUrl("http://stackoverflow.com/users/532462/turtleboy");
}else{
webView.getSettings().setSupportZoom(true);
webView.getSettings().setBuiltInZoomControls(true);
webView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY);
webView.setScrollbarFadingEnabled(true);
webView.getSettings().setLoadsImagesAutomatically(true);
webView.getSettings().setDomStorageEnabled(true);
webView.getSettings().setAppCacheEnabled(true);
// Set cache size to 8 mb by default. should be more than enough
webView.getSettings().setAppCacheMaxSize(1024*1024*8);
// This next one is crazy. It's the DEFAULT location for your app's cache
// But it didn't work for me without this line.
// UPDATE: no hardcoded path. Thanks to Kevin Hawkins
String appCachePath = getApplicationContext().getCacheDir().getAbsolutePath();
Log.e(TAG, "appCachePath = " + appCachePath);
webView.getSettings().setAppCachePath(appCachePath);
webView.getSettings().setAllowFileAccess(true);
webView.getSettings().setJavaScriptEnabled(true);
// Load the URLs inside the WebView, not in the external web browser
webView.setWebViewClient(new WebViewClient());
webView.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ONLY);
// webView.loadUrl("http://www.bmimobile.co.uk/", getHeaders());
webView.loadUrl("http://stackoverflow.com/users/532462/turtleboy");
}
}
[edit2]
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="uk.bmi.mobile"
android:versionCode="5"
android:versionName="1.0.4" >
<!-- GCM requires Android SDK version 2.2 (API level <img src="http://www.androidhive.info/wp-includes/images/smilies/icon_cool.gif" alt="8)" class="wp-smiley"> or above. -->
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="16" />
<!-- GCM connects to Internet Services. -->
<uses-permission android:name="android.permission.INTERNET" />
<!-- GCM requires a Google account. -->
<uses-permission android:name="android.permission.GET_ACCOUNTS" />
<!-- Keeps the processor from sleeping when a message is received. -->
<uses-permission android:name="android.permission.WAKE_LOCK" />
<!-- Creates a custom permission so only this app can receive its messages. -->
<permission
android:name="uk.bmi.mobile.permission.C2D_MESSAGE"
android:protectionLevel="signature" />
<uses-permission android:name="uk.bmi.mobile.permission.C2D_MESSAGE" />
<!-- This app has permission to register and receive data message. -->
<uses-permission android:name="com.google.android.c2dm.permission.RECEIVE" />
<!-- Network State Permissions to detect Internet status -->
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<!-- Permission to vibrate -->
<uses-permission android:name="android.permission.VIBRATE" />
<uses-permission android:name="android.permisson.ACCESS_WIFI_STATE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<!-- Main activity. -->
<application
android:icon="@drawable/bmi_icon"
android:label="@string/app_name"
android:name="uk.bmi.mobile.ApplicationExt" >
<!-- Register Activity -->
<activity
android:name=".RegisterActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<!-- Main Activity -->
<activity
android:name="uk.bmi.mobile.MainActivity"
android:configChanges="orientation|keyboardHidden"
android:label="@string/app_name"
android:screenOrientation="portrait" >
</activity>
<receiver
android:name="com.google.android.gcm.GCMBroadcastReceiver"
android:permission="com.google.android.c2dm.permission.SEND" >
<intent-filter>
<!-- Receives the actual messages. -->
<action android:name="com.google.android.c2dm.intent.RECEIVE" />
<!-- Receives the registration id. -->
<action android:name="com.google.android.c2dm.intent.REGISTRATION" />
<category android:name="uk.bmi.mobile" />
</intent-filter>
</receiver>
<service android:name="uk.bmi.mobile.GCMIntentService" />
</application>
</manifest>
bạn đã đặt quyền READ_EXTERNAL_STORAGE chưa? –
@Yalla T. Xin chào, tôi không cần phải đưa nó vào? – turtleboy
Không, tôi có cần bao gồm không? – turtleboy