Java tutorial
/* * Copyright (C) 2007 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package android.webkit; import android.annotation.Nullable; import android.content.Context; /** * This class allows developers to determine whether any WebView used in the * application has stored any of the following types of browsing data and * to clear any such stored data for all WebViews in the application. * <ul> * <li>Username/password pairs for web forms</li> * <li>HTTP authentication username/password pairs</li> * <li>Data entered into text fields (e.g. for autocomplete suggestions)</li> * </ul> */ public abstract class WebViewDatabase { /** * @hide Since API level {@link android.os.Build.VERSION_CODES#JELLY_BEAN_MR1} */ protected static final String LOGTAG = "webviewdatabase"; public static WebViewDatabase getInstance(Context context) { return WebViewFactory.getProvider().getWebViewDatabase(context); } /** * Gets whether there are any saved username/password pairs for web forms. * Note that these are unrelated to HTTP authentication credentials. * * @return {@code true} if there are any saved username/password pairs * @see WebView#savePassword * @see #clearUsernamePassword * @deprecated Saving passwords in WebView will not be supported in future versions. */ @Deprecated public abstract boolean hasUsernamePassword(); /** * Clears any saved username/password pairs for web forms. * Note that these are unrelated to HTTP authentication credentials. * * @see WebView#savePassword * @see #hasUsernamePassword * @deprecated Saving passwords in WebView will not be supported in future versions. */ @Deprecated public abstract void clearUsernamePassword(); /** * Gets whether there are any saved credentials for HTTP authentication. * * @return whether there are any saved credentials * @see #getHttpAuthUsernamePassword * @see #setHttpAuthUsernamePassword * @see #clearHttpAuthUsernamePassword */ public abstract boolean hasHttpAuthUsernamePassword(); /** * Clears any saved credentials for HTTP authentication. This method only clears the username * and password stored in WebViewDatabase instance. The username and password are not read from * the {@link WebViewDatabase} during {@link WebViewClient#onReceivedHttpAuthRequest}. It is up * to the app to do this or not. * <p> * The username and password used for http authentication might be cached in the network stack * itself, and are not cleared when this method is called. WebView does not provide a special * mechanism to clear HTTP authentication for implementing client logout. The client logout * mechanism should be implemented by the Web site designer (such as server sending a HTTP 401 * for invalidating credentials). * * @see #getHttpAuthUsernamePassword * @see #setHttpAuthUsernamePassword * @see #hasHttpAuthUsernamePassword */ public abstract void clearHttpAuthUsernamePassword(); /** * Stores HTTP authentication credentials for a given host and realm to the {@link WebViewDatabase} * instance. * <p> * To use HTTP authentication, the embedder application has to implement * {@link WebViewClient#onReceivedHttpAuthRequest}, and call {@link HttpAuthHandler#proceed} * with the correct username and password. * <p> * The embedder app can get the username and password any way it chooses, and does not have to * use {@link WebViewDatabase}. * <p> * Notes: * <li> * {@link WebViewDatabase} is provided only as a convenience to store and retrieve http * authentication credentials. WebView does not read from it during HTTP authentication. * </li> * <li> * WebView does not provide a special mechanism to clear HTTP authentication credentials for * implementing client logout. The client logout mechanism should be implemented by the Web site * designer (such as server sending a HTTP 401 for invalidating credentials). * </li> * * @param host the host to which the credentials apply * @param realm the realm to which the credentials apply * @param username the username * @param password the password * @see #getHttpAuthUsernamePassword * @see #hasHttpAuthUsernamePassword * @see #clearHttpAuthUsernamePassword */ public abstract void setHttpAuthUsernamePassword(String host, String realm, String username, String password); /** * Retrieves HTTP authentication credentials for a given host and realm from the {@link * WebViewDatabase} instance. * * @param host the host to which the credentials apply * @param realm the realm to which the credentials apply * @return the credentials as a String array, if found. The first element * is the username and the second element is the password. {@code null} if * no credentials are found. * @see #setHttpAuthUsernamePassword * @see #hasHttpAuthUsernamePassword * @see #clearHttpAuthUsernamePassword */ @Nullable public abstract String[] getHttpAuthUsernamePassword(String host, String realm); /** * Gets whether there is any saved data for web forms. * * @return whether there is any saved data for web forms * @see #clearFormData */ @Deprecated public abstract boolean hasFormData(); /** * Clears any saved data for web forms. * * @see #hasFormData */ @Deprecated public abstract void clearFormData(); }