Java tutorial
/** * This file is part of ElasticDroid. * * ElasticDroid is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * ElasticDroid 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 ElasticDroid. If not, see <http://www.gnu.org/licenses/>. * * Authored by Siddhu Warrier on 1 Nov 2010 */ package org.elasticdroid.model; import java.util.regex.Pattern; import org.elasticdroid.db.ElasticDroidDB; import org.elasticdroid.db.tblinfo.LoginTbl; import org.elasticdroid.model.tpl.GenericModel; import org.elasticdroid.tpl.GenericActivity; import android.content.ContentValues; import android.database.SQLException; import android.database.sqlite.SQLiteDatabase; import android.util.Log; import com.amazonaws.AmazonClientException; import com.amazonaws.AmazonServiceException; import com.amazonaws.auth.BasicAWSCredentials; import com.amazonaws.services.identitymanagement.AmazonIdentityManagementClient; import com.amazonaws.services.identitymanagement.model.User; /** * This class is the model class for the Login window. It performs the following actions: * a) Verifies credentials by connecting to AWS. * b) Stores valid credentials in database. * c) Notifies observers (presently the Login activity alone) that authentication is valid (or not). * d) Can be used to retrieve saved credentials from SQLite DB. * @author Siddhu Warrier * * 1 Nov 2010 */ public class LoginModel extends GenericModel<String, Void, Object> { /** * To call super Constructor alone. To read what this constructor * does, please refer to the superclass documentation. * @param genericActivity The activity which started this model */ public LoginModel(GenericActivity genericActivity) { super(genericActivity); } /** * Check AWS credentials, and save to DB if valid. * * When this method finishes, the * {@link org.elasticdroid.model.tpl.GenericModel#onPostExecute(Object)} is called, which * notifies the view. * * This method, inherited from Android AsyncTask is automagically run in a separate background * thread. */ @Override protected Object doInBackground(String... params) { return performLogin(params); } public Object performLogin(String... params) { //we need username, accessKey, secretAccessKey if (params.length != 3) { Log.e(this.getClass().getName(), "Need 3 params."); //TODO do something better. return null; } //create credentials using the BasicAWSCredentials class BasicAWSCredentials credentials = new BasicAWSCredentials(params[1], params[2]); //create an IAM client AmazonIdentityManagementClient idManagementClient = new AmazonIdentityManagementClient(credentials); User userData = null; Log.v(this.getClass().getName(), "Executing performLogin AsyncTask..."); try { userData = idManagementClient.getUser().getUser();//ensure the user ID is //matched to the access and secret access keys } catch (AmazonServiceException amazonServiceException) { //if an error response is returned by AmazonIdentityManagement indicating either a //problem with the data in the request, or a server side issue. Log.e(this.getClass().getName(), "Exception:" + amazonServiceException.getMessage()); return amazonServiceException; } catch (AmazonClientException amazonClientException) { //If any internal errors are encountered inside the client while attempting to make //the request or handle the response. For example if a network connection is not available. Log.e(this.getClass().getName(), "Exception:" + amazonClientException.getMessage()); return amazonClientException; } //if we get here, the userData variable has been initialised. //check if the user name specified by the user corresponds to the //user name associated with the acess and secret access keys specified String username = userData.getUserName(); if (username != null) { //this is an IAM username if (!username.equals(params[0])) { /*Log.e(this.getClass().getName(), "Username " + params[0] + ", " + userData. getUserName() + " does not correspond to access and secret access key!");*/ //return *not throw* an illegalArgumentException, because this is a different thread. return new IllegalArgumentException( "Username does not correspond to access and " + "secret access key!"); } } else { //this is a proper AWS account, and not an IAM username. //check if the username is a proper email address. Java regexes look +vely awful! Pattern emailPattern = Pattern.compile("^[\\w\\.-]+@([\\w\\-]+\\.)+[A-Z]{2,4}$", Pattern.CASE_INSENSITIVE); //if this is not an email address if (!emailPattern.matcher(params[0]).matches()) { return new IllegalArgumentException( "Username is an AWS account. Please enter a" + " valid email address."); } } /*writing to DB*/ // if we get here, then write the data to the DB ElasticDroidDB elasticDroidDB = new ElasticDroidDB(activity); //open the database for writing SQLiteDatabase db = elasticDroidDB.getWritableDatabase(); ContentValues rowValues = new ContentValues(); //check if the username already exists //set the data to write rowValues.put(LoginTbl.COL_USERNAME, params[0]); rowValues.put(LoginTbl.COL_ACCESSKEY, params[1]); rowValues.put(LoginTbl.COL_SECRETACCESSKEY, params[2]); //if data is found, update. if (db.query(LoginTbl.TBL_NAME, new String[] {}, LoginTbl.COL_USERNAME + "=?", new String[] { params[0] }, null, null, null).getCount() != 0) { try { db.update(LoginTbl.TBL_NAME, rowValues, LoginTbl.COL_USERNAME + "=?", new String[] { params[0] }); } catch (SQLException sqlException) { Log.e(this.getClass().getName(), "SQLException: " + sqlException.getMessage()); return sqlException; //return the exception for the View to process. } finally { db.close(); } } else { //now write the data in, replacing if necessary! try { db.insertOrThrow(LoginTbl.TBL_NAME, null, rowValues); } catch (SQLException sqlException) { Log.e(this.getClass().getName(), "SQLException: " + sqlException.getMessage()); return sqlException; //return the exception for the View to process. } finally { db.close(); } } return true; } }