我有一个
Android应用程序,只是一个网站.我希望该应用程序缓存网站的页面以供离线使用.
我正在进行一个简单的测试,看看缓存是否正常工作,但不幸的是,当我离线时,加载了一个我以前在线模式加载的页面.为了使事情更清晰,在加载在线模式下,我将加载以下2页.
webView.loadUrl("http://www.bmimobile.co.uk/why-bmi.PHP",getHeaders());
webView.loadUrl("http://www.bmimobile.co.uk/",getHeaders());
.
我希望将“why-bmi.PHP”页面加载到缓存以及随后的页面http://www.bmimobile.co.uk/.后一页面有一个链接,指的是第一页.如果我然后从应用程序出来,关闭网络适配器,然后回到应用程序“http://www.bmimobile.co.uk/”页面显示,但是当我点击该页面的“为什么 – bmi”链接不显示.我的口味信息显示说“错误加载页面”.
任何人都可以告诉我为什么webview没有缓存加载的页面以供以后离线使用？
这是主要的活动,我已经扩展了定义Appcachepath的Application对象.
提前致谢
马特
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();
}
}
}
这是当应用程序首次加载在在线模式时的日志记录
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
.
这是当我从应用程序中退出网络适配器,然后在离线模式下回到应用程序的日志记录.
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]
实际上,仔细检查日志记录,在加载在线模式下似乎已经改变了.以下是omline模式下的logcat.缓存存储似乎有问题.
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
.
[笔记]
如果我在在线模式下点击why-bmi按钮,然后从应用程序中出来,请关闭适配器,然后再次单击why-bmi按钮,然后显示“错误加载页面”消息.
如果我改变到以下url,我的SO页面显示.如果我点击链接到我的赏金页面(这个页面),然后离线,这个SO页面是按照你所期望的显示,但是如果你在离线模式下点击赏金链接,那么它显示.所以SO站点和bmi站点之间存在差异.
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,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("https://stackoverflow.com/users/532462/turtleboy?tab=bounties");
webView.loadUrl("https://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,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("https://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>
解决方法
这不是您问题的确切答案,因为您正在询问Webview缓存.但是,它可以达到相同的结果.
// saving page from web to file
File file = new File(this.getExternalFilesDir(null),"fileName.html");
FileUtils.copyURLToFile(new URL("http://www.bmimobile.co.uk/why-bmi.PHP"),file);
// loading saved file in webview
webview.loadUrl("file://" + file.getPath());
这是一个更灵活的方法,因为您可以控制加载,保存等等.