Java tutorial
/* ownCloud Android client application * Copyright (C) 2012-2013 ownCloud Inc. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2, * as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * */ package com.owncloud.android.operations; import java.io.IOException; import org.apache.commons.httpclient.Credentials; import com.owncloud.android.Log_OC; import com.owncloud.android.authentication.AccountAuthenticator; import com.owncloud.android.network.BearerCredentials; import com.owncloud.android.network.OwnCloudClientUtils; import com.owncloud.android.operations.RemoteOperationResult.ResultCode; import android.accounts.Account; import android.accounts.AccountManager; import android.accounts.AccountsException; import android.app.Activity; import android.content.Context; import android.os.Handler; import eu.alefzero.webdav.WebdavClient; /** * Operation which execution involves one or several interactions with an ownCloud server. * * Provides methods to execute the operation both synchronously or asynchronously. * * @author David A. Velasco */ public abstract class RemoteOperation implements Runnable { private static final String TAG = RemoteOperation.class.getSimpleName(); /** ownCloud account in the remote ownCloud server to operate */ private Account mAccount = null; /** Android Application context */ private Context mContext = null; /** Object to interact with the remote server */ private WebdavClient mClient = null; /** Callback object to notify about the execution of the remote operation */ private OnRemoteOperationListener mListener = null; /** Handler to the thread where mListener methods will be called */ private Handler mListenerHandler = null; /** Activity */ private Activity mCallerActivity; /** * Abstract method to implement the operation in derived classes. */ protected abstract RemoteOperationResult run(WebdavClient client); /** * Synchronously executes the remote operation on the received ownCloud account. * * Do not call this method from the main thread. * * This method should be used whenever an ownCloud account is available, instead of {@link #execute(WebdavClient)}. * * @param account ownCloud account in remote ownCloud server to reach during the execution of the operation. * @param context Android context for the component calling the method. * @return Result of the operation. */ public final RemoteOperationResult execute(Account account, Context context) { if (account == null) throw new IllegalArgumentException("Trying to execute a remote operation with a NULL Account"); if (context == null) throw new IllegalArgumentException("Trying to execute a remote operation with a NULL Context"); mAccount = account; mContext = context.getApplicationContext(); try { mClient = OwnCloudClientUtils.createOwnCloudClient(mAccount, mContext); } catch (Exception e) { Log_OC.e(TAG, "Error while trying to access to " + mAccount.name, e); return new RemoteOperationResult(e); } return run(mClient); } /** * Synchronously executes the remote operation * * Do not call this method from the main thread. * * @param client Client object to reach an ownCloud server during the execution of the operation. * @return Result of the operation. */ public final RemoteOperationResult execute(WebdavClient client) { if (client == null) throw new IllegalArgumentException("Trying to execute a remote operation with a NULL WebdavClient"); mClient = client; return run(client); } /** * Asynchronously executes the remote operation * * This method should be used whenever an ownCloud account is available, instead of {@link #execute(WebdavClient)}. * * @param account ownCloud account in remote ownCloud server to reach during the execution of the operation. * @param context Android context for the component calling the method. * @param listener Listener to be notified about the execution of the operation. * @param listenerHandler Handler associated to the thread where the methods of the listener objects must be called. * @return Thread were the remote operation is executed. */ public final Thread execute(Account account, Context context, OnRemoteOperationListener listener, Handler listenerHandler, Activity callerActivity) { if (account == null) throw new IllegalArgumentException("Trying to execute a remote operation with a NULL Account"); if (context == null) throw new IllegalArgumentException("Trying to execute a remote operation with a NULL Context"); mAccount = account; mContext = context.getApplicationContext(); mCallerActivity = callerActivity; mClient = null; // the client instance will be created from mAccount and mContext in the runnerThread to create below if (listener == null) { throw new IllegalArgumentException( "Trying to execute a remote operation asynchronously without a listener to notiy the result"); } mListener = listener; if (listenerHandler == null) { throw new IllegalArgumentException( "Trying to execute a remote operation asynchronously without a handler to the listener's thread"); } mListenerHandler = listenerHandler; Thread runnerThread = new Thread(this); runnerThread.start(); return runnerThread; } /** * Asynchronously executes the remote operation * * @param client Client object to reach an ownCloud server during the execution of the operation. * @param listener Listener to be notified about the execution of the operation. * @param listenerHandler Handler associated to the thread where the methods of the listener objects must be called. * @return Thread were the remote operation is executed. */ public final Thread execute(WebdavClient client, OnRemoteOperationListener listener, Handler listenerHandler) { if (client == null) { throw new IllegalArgumentException("Trying to execute a remote operation with a NULL WebdavClient"); } mClient = client; if (listener == null) { throw new IllegalArgumentException( "Trying to execute a remote operation asynchronously without a listener to notiy the result"); } mListener = listener; if (listenerHandler == null) { throw new IllegalArgumentException( "Trying to execute a remote operation asynchronously without a handler to the listener's thread"); } mListenerHandler = listenerHandler; Thread runnerThread = new Thread(this); runnerThread.start(); return runnerThread; } /** * Synchronously retries the remote operation using the same WebdavClient in the last call to {@link RemoteOperation#execute(WebdavClient)} * * @param listener Listener to be notified about the execution of the operation. * @param listenerHandler Handler associated to the thread where the methods of the listener objects must be called. * @return Thread were the remote operation is executed. */ public final RemoteOperationResult retry() { return execute(mClient); } /** * Asynchronously retries the remote operation using the same WebdavClient in the last call to {@link RemoteOperation#execute(WebdavClient, OnRemoteOperationListener, Handler)} * * @param listener Listener to be notified about the execution of the operation. * @param listenerHandler Handler associated to the thread where the methods of the listener objects must be called. * @return Thread were the remote operation is executed. */ public final Thread retry(OnRemoteOperationListener listener, Handler listenerHandler) { return execute(mClient, listener, listenerHandler); } /** * Asynchronous execution of the operation * started by {@link RemoteOperation#execute(WebdavClient, OnRemoteOperationListener, Handler)}, * and result posting. * * TODO refactor && clean the code; now it's a mess */ @Override public final void run() { RemoteOperationResult result = null; boolean repeat = false; do { try { if (mClient == null) { if (mAccount != null && mContext != null) { if (mCallerActivity != null) { mClient = OwnCloudClientUtils.createOwnCloudClient(mAccount, mContext, mCallerActivity); } else { mClient = OwnCloudClientUtils.createOwnCloudClient(mAccount, mContext); } } else { throw new IllegalStateException( "Trying to run a remote operation asynchronously with no client instance or account"); } } } catch (IOException e) { Log_OC.e(TAG, "Error while trying to access to " + mAccount.name, new AccountsException("I/O exception while trying to authorize the account", e)); result = new RemoteOperationResult(e); } catch (AccountsException e) { Log_OC.e(TAG, "Error while trying to access to " + mAccount.name, e); result = new RemoteOperationResult(e); } if (result == null) result = run(mClient); repeat = false; if (mCallerActivity != null && mAccount != null && mContext != null && !result.isSuccess() && // (result.getCode() == ResultCode.UNAUTHORIZED || (result.isTemporalRedirection() && result.isIdPRedirection()))) { (result.getCode() == ResultCode.UNAUTHORIZED || result.isIdPRedirection())) { /// possible fail due to lack of authorization in an operation performed in foreground Credentials cred = mClient.getCredentials(); String ssoSessionCookie = mClient.getSsoSessionCookie(); if (cred != null || ssoSessionCookie != null) { /// confirmed : unauthorized operation AccountManager am = AccountManager.get(mContext); boolean bearerAuthorization = (cred != null && cred instanceof BearerCredentials); boolean samlBasedSsoAuthorization = (cred == null && ssoSessionCookie != null); if (bearerAuthorization) { am.invalidateAuthToken(AccountAuthenticator.ACCOUNT_TYPE, ((BearerCredentials) cred).getAccessToken()); } else if (samlBasedSsoAuthorization) { am.invalidateAuthToken(AccountAuthenticator.ACCOUNT_TYPE, ssoSessionCookie); } else { am.clearPassword(mAccount); } mClient = null; repeat = true; // when repeated, the creation of a new OwnCloudClient after erasing the saved credentials will trigger the login activity result = null; } } } while (repeat); final RemoteOperationResult resultToSend = result; if (mListenerHandler != null && mListener != null) { mListenerHandler.post(new Runnable() { @Override public void run() { mListener.onRemoteOperationFinish(RemoteOperation.this, resultToSend); } }); } } /** * Returns the current client instance to access the remote server. * * @return Current client instance to access the remote server. */ public final WebdavClient getClient() { return mClient; } }