WebView缓存数据目录

Question

在我的代码中，我将一个自定义缓存目录设置为SD卡，并将"WebView.getSettings（）.setAppCachePath（"）"指向该路径，但操作系统将缓存发送到默认缓存（/data/data.com/your.package.appname/cache），但是数据没有进入其中。我使用自定义目录的原因是缓存很大而且是临时的，所以我需要用户能够删除特定的缓存。

我是不是遗漏了什么？我们将一如既往地感谢您的任何帮助、代码或建议。

谢谢。

public class DocumentView extends Activity {
 /**
 * -- Called when the activity is first created.
 * ================================================
 **/
@Override
public void onCreate(final Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
String l = getIntent().getStringExtra("LABEL");
    CreateCacheDirectory();
     /**
     * -- Set up the WebView
     * ========================================================
     **/
    final String url = getIntent().getStringExtra("url");// get url that
                                                        // passed from
                                                       // previous
                                                      // Activity
    mWebView = (WebView) findViewById(R.id.webView1);
    mWebView.getSettings().setDomStorageEnabled(true);
    // Set cache size to 8 mb by default. should be more than enough
    mWebView.getSettings().setAppCacheMaxSize(1024 * 1024 * 8);
    // The DEFAULT location for the cache
    mWebView.getSettings().setAppCachePath(extStorageDirectory
            + "/myCompany/myApp/cache/" + l);
    mWebView.getSettings().setAllowFileAccess(true);
    mWebView.getSettings().setAppCacheEnabled(true);
    mWebView.getSettings().setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK);
    mWebView.loadUrl(url);
    mWebView.setWebChromeClient(new WebChromeClient() {
        public void onProgressChanged(WebView view, int progress) {
            activity.setProgress(progress * 100);
            pd.show();
            if (progress == 100)
                pd.dismiss();
        }
        @Override
        public void onReachedMaxAppCacheSize(long spaceNeeded,
                long totalUsedQuota, WebStorage.QuotaUpdater quotaUpdater) {
            quotaUpdater.updateQuota(spaceNeeded * 2);
        }
    });
    mWebView.setWebViewClient(new WebViewClient() {
        @Override
        public void onReceivedError(WebView view, int errorCode,
                String description, String failingUrl) {
            // The redirect
            if (url.equals(failingUrl)) {
                // error.html is the place we are redirected to by the
                // server if we are online
                mWebView.loadUrl("http:www.aero-technologies.us/error.html");
                return;
            } else if (url.equals(failingUrl)) { // The cache failed – We
                                                // don't have an offline
                                               // version to show
                // This code removes the ugly android's "can't open page"
                // and simply shows a dialog stating we have no network
                view.loadData("", "text/html", "UTF-8");
                // TODO -->showDialog(DIALOG_NONETWORK);
            }
        }
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }
    });
public void CreateCacheDirectory() {
    if (android.os.Environment.getExternalStorageState().equals(
            android.os.Environment.MEDIA_MOUNTED)) {
        String l = getIntent().getStringExtra("LABEL");
        extStorageDirectory = Environment.getExternalStorageDirectory()
                .toString();
        File cacheDirectory = new File(extStorageDirectory
                + "/myCompany/myApp/cache/" + l);// Create a Folder object
                                                           // for the parent
                                                          // directory
        cacheDirectory.mkdirs();// Have the object build the folder
                               // if needed.
    } else if (android.os.Environment.getExternalStorageState().equals(
            android.os.Environment.MEDIA_MOUNTED_READ_ONLY)) {
        Alerts.sdCardMissing(this);
    }
}

Answer 1

通过阅读WebSettings代码可以看出，WebSettings上的缓存配置仅适用于HTML5应用程序：

http://www.grepcode.com/file/repository.grepcode.com/java/ext/com.google.android/android/2.3.3_r1/android/webkit/WebSettings.java#181

Answer 2

这是Chromium bug 245549，于2014年11月底修复，因此可能会影响6.0以下的所有版本的Android（API 23）。