Java tutorial
/* * Copyright (c) 2014, WSO2 Inc. (http://www.wso2.org) All Rights Reserved. * * WSO2 Inc. licenses this file to you 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 org.wso2.iot.agent.utils; import android.app.ActivityManager; import android.app.NotificationManager; import android.app.PendingIntent; import android.app.admin.DevicePolicyManager; import android.content.ComponentName; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.content.pm.ApplicationInfo; import android.content.pm.PackageManager; import android.content.pm.ResolveInfo; import android.content.res.Resources; import android.location.Location; import android.net.ConnectivityManager; import android.net.NetworkInfo; import android.support.v4.app.NotificationCompat; import android.support.v4.app.TaskStackBuilder; import android.util.Base64; import android.util.Log; import android.widget.Toast; import com.fasterxml.jackson.core.JsonGenerationException; import com.fasterxml.jackson.databind.DeserializationFeature; import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.ObjectMapper; import com.fasterxml.jackson.databind.SerializationFeature; import org.bouncycastle.jce.PKCS10CertificationRequest; import org.bouncycastle.jce.provider.asymmetric.ec.KeyPairGenerator; import org.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; import org.wso2.iot.agent.AndroidAgentException; import org.wso2.iot.agent.R; import org.wso2.iot.agent.api.ApplicationManager; import org.wso2.iot.agent.beans.AppRestriction; import org.wso2.iot.agent.beans.Operation; import org.wso2.iot.agent.beans.ServerConfig; import org.wso2.iot.agent.beans.UnregisterProfile; import org.wso2.iot.agent.events.listeners.DeviceCertCreationListener; import org.wso2.iot.agent.proxy.APIController; import org.wso2.iot.agent.proxy.beans.EndPointInfo; import org.wso2.iot.agent.proxy.interfaces.APIResultCallBack; import org.wso2.iot.agent.proxy.utils.Constants.HTTP_METHODS; import org.wso2.iot.agent.services.AgentDeviceAdminReceiver; import org.wso2.iot.agent.services.DynamicClientManager; import org.wso2.iot.agent.services.LocationUpdateReceiver; import org.wso2.iot.agent.services.PolicyOperationsMapper; import org.wso2.iot.agent.services.PolicyRevokeHandler; import org.wso2.iot.agent.services.ResultPayload; import org.wso2.iot.agent.services.SystemServiceResponseReceiver; import org.wso2.iot.agent.services.location.LocationService; import java.io.BufferedInputStream; import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.security.InvalidKeyException; import java.security.Key; import java.security.KeyPair; import java.security.KeyStore; import java.security.KeyStoreException; import java.security.NoSuchAlgorithmException; import java.security.NoSuchProviderException; import java.security.SignatureException; import java.security.cert.CertificateException; import java.security.cert.CertificateFactory; import java.security.cert.X509Certificate; import java.util.ArrayList; import java.util.Calendar; import java.util.Date; import java.util.List; import java.util.Map; import javax.security.auth.x500.X500Principal; /** * This class represents all the common functions used throughout the application. */ public class CommonUtils { public static String TAG = CommonUtils.class.getSimpleName(); private static final String PROTOCOL_HTTPS = "https://"; private static final String PROTOCOL_HTTP = "http://"; private static final String COLON = ":"; /** * Calls the secured API. * @param context -The Activity which calls an API.. * @param endpoint -The API endpoint. * @param methodType -The method type. * @param apiResultCallBack -The API result call back object. * @param requestCode -The request code. */ public static void callSecuredAPI(Context context, String endpoint, HTTP_METHODS methodType, String requestParams, APIResultCallBack apiResultCallBack, int requestCode) { EndPointInfo apiUtilities = new EndPointInfo(); ServerConfig utils = new ServerConfig(); apiUtilities.setEndPoint(endpoint); apiUtilities.setHttpMethod(methodType); if (requestParams != null) { apiUtilities.setRequestParams(requestParams); } if (endpoint.contains(Constants.NOTIFICATION_ENDPOINT)) { apiUtilities.setIsJSONArrayRequest(true); } APIController apiController; if (org.wso2.iot.agent.proxy.utils.Constants.Authenticator.AUTHENTICATOR_IN_USE .equals(org.wso2.iot.agent.proxy.utils.Constants.Authenticator.MUTUAL_SSL_AUTHENTICATOR)) { apiController = new APIController(); apiController.securedNetworkCall(apiResultCallBack, requestCode, apiUtilities, context); } else { String clientKey = Preference.getString(context, Constants.CLIENT_ID); String clientSecret = Preference.getString(context, Constants.CLIENT_SECRET); if (utils.getHostFromPreferences(context) != null && !utils.getHostFromPreferences(context).isEmpty() && clientKey != null && !clientKey.isEmpty() && !clientSecret.isEmpty()) { apiController = new APIController(clientKey, clientSecret); apiController.invokeAPI(apiUtilities, apiResultCallBack, requestCode, context.getApplicationContext()); } } } /** * Generates keys, CSR and certificates for the devices. * @param context - Application context. * @param listener - DeviceCertCreationListener which provide device . */ public static void generateDeviceCertificate(final Context context, final DeviceCertCreationListener listener) throws AndroidAgentException { if (context.getFileStreamPath(Constants.DEVICE_CERTIFCATE_NAME).exists()) { try { listener.onDeviceCertCreated( new BufferedInputStream(context.openFileInput(Constants.DEVICE_CERTIFCATE_NAME))); } catch (FileNotFoundException e) { Log.e(TAG, e.getMessage()); } } else { try { ServerConfig utils = new ServerConfig(); final KeyPair deviceKeyPair = KeyPairGenerator.getInstance(Constants.DEVICE_KEY_TYPE) .generateKeyPair(); X500Principal subject = new X500Principal(Constants.DEVICE_CSR_INFO); PKCS10CertificationRequest csr = new PKCS10CertificationRequest(Constants.DEVICE_KEY_ALGO, subject, deviceKeyPair.getPublic(), null, deviceKeyPair.getPrivate()); EndPointInfo endPointInfo = new EndPointInfo(); endPointInfo.setHttpMethod(org.wso2.iot.agent.proxy.utils.Constants.HTTP_METHODS.POST); endPointInfo.setEndPoint(utils.getAPIServerURL(context) + Constants.SCEP_ENDPOINT); endPointInfo.setRequestParams(Base64.encodeToString(csr.getEncoded(), Base64.DEFAULT)); new APIController().invokeAPI(endPointInfo, new APIResultCallBack() { @Override public void onReceiveAPIResult(Map<String, String> result, int requestCode) { try { CertificateFactory certFactory = CertificateFactory.getInstance("X.509"); InputStream in = new ByteArrayInputStream( Base64.decode(result.get("response"), Base64.DEFAULT)); X509Certificate cert = (X509Certificate) certFactory.generateCertificate(in); ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream(); KeyStore keyStore = KeyStore.getInstance("PKCS12"); keyStore.load(null); keyStore.setKeyEntry(Constants.DEVICE_CERTIFCATE_ALIAS, (Key) deviceKeyPair.getPrivate(), Constants.DEVICE_CERTIFCATE_PASSWORD.toCharArray(), new java.security.cert.Certificate[] { cert }); keyStore.store(byteArrayOutputStream, Constants.DEVICE_CERTIFCATE_PASSWORD.toCharArray()); FileOutputStream outputStream = context.openFileOutput(Constants.DEVICE_CERTIFCATE_NAME, Context.MODE_PRIVATE); outputStream.write(byteArrayOutputStream.toByteArray()); byteArrayOutputStream.close(); outputStream.close(); try { listener.onDeviceCertCreated(new BufferedInputStream( context.openFileInput(Constants.DEVICE_CERTIFCATE_NAME))); } catch (FileNotFoundException e) { Log.e(TAG, e.getMessage()); } } catch (CertificateException | KeyStoreException | NoSuchAlgorithmException | IOException e) { Log.e(TAG, e.getMessage(), e); } } }, Constants.SCEP_REQUEST_CODE, context, true); } catch (NoSuchAlgorithmException e) { throw new AndroidAgentException("No algorithm for key generation", e); } catch (SignatureException e) { throw new AndroidAgentException("Invalid Signature", e); } catch (NoSuchProviderException e) { throw new AndroidAgentException("Invalid provider", e); } catch (InvalidKeyException e) { throw new AndroidAgentException("Invalid key", e); } } } /** * Clear application data. * @param context - Application context. */ public static void clearAppData(Context context) throws AndroidAgentException { try { revokePolicy(context); } catch (SecurityException e) { throw new AndroidAgentException("Error occurred while revoking policy", e); } finally { Preference.clearPreferences(context); context.deleteDatabase(Constants.EMM_DB); } Toast.makeText(context, R.string.toast_message_disenroll, Toast.LENGTH_LONG).show(); } /** * Returns network availability status. * @param context - Application context. * @return - Network availability status. */ public static boolean isNetworkAvailable(Context context) { ConnectivityManager connectivityManager = (ConnectivityManager) context .getSystemService(Context.CONNECTIVITY_SERVICE); NetworkInfo info = connectivityManager.getActiveNetworkInfo(); return (info != null && info.isConnected()); } /** * Convert given object to json formatted string. * @param obj Object to be converted. * @return Json formatted string. * @throws AndroidAgentException */ public static String toJSON(Object obj) throws AndroidAgentException { try { ObjectMapper mapper = new ObjectMapper(); return mapper.writeValueAsString(obj); } catch (JsonMappingException e) { throw new AndroidAgentException("Error occurred while mapping class to json", e); } catch (JsonGenerationException e) { throw new AndroidAgentException("Error occurred while generating json", e); } catch (IOException e) { throw new AndroidAgentException("Error occurred while reading the stream", e); } } /** * This method is used to initiate the oauth client app unregister process. * * @param context Application context * @throws AndroidAgentException */ public static void unRegisterClientApp(Context context, APIResultCallBack apiCallBack) throws AndroidAgentException { String serverIP = Constants.DEFAULT_HOST; String prefIP = Preference.getString(context.getApplicationContext(), Constants.PreferenceFlag.IP); if (prefIP != null) { serverIP = prefIP; } if (serverIP != null && !serverIP.isEmpty()) { String applicationName = Preference.getString(context, Constants.CLIENT_NAME); String consumerKey = Preference.getString(context, Constants.CLIENT_ID); String userId = Preference.getString(context, Constants.USERNAME); if (applicationName != null && !applicationName.isEmpty() && consumerKey != null && !consumerKey.isEmpty() && userId != null && !userId.isEmpty()) { UnregisterProfile profile = new UnregisterProfile(); profile.setApplicationName(applicationName); profile.setConsumerKey(consumerKey); profile.setUserId(userId); ServerConfig utils = new ServerConfig(); utils.setServerIP(serverIP); DynamicClientManager dynamicClientManager = new DynamicClientManager(); boolean isUnregistered = dynamicClientManager.unregisterClient(profile, utils, context, apiCallBack); if (!isUnregistered) { Log.e(TAG, "Error occurred while removing the OAuth client app"); } } else { Log.e(TAG, "Client credential is not available"); } } else { Log.e(TAG, "There is no valid IP to contact the server"); } } /** * Disable admin privileges. * @param context - Application context. */ public static void disableAdmin(Context context) { DevicePolicyManager devicePolicyManager; ComponentName demoDeviceAdmin; devicePolicyManager = (DevicePolicyManager) context.getSystemService(Context.DEVICE_POLICY_SERVICE); demoDeviceAdmin = new ComponentName(context, AgentDeviceAdminReceiver.class); devicePolicyManager.removeActiveAdmin(demoDeviceAdmin); } /** * Revoke currently enforced policy. * @param context - Application context. */ public static void revokePolicy(Context context) throws AndroidAgentException { String payload = Preference.getString(context, Constants.PreferenceFlag.APPLIED_POLICY); PolicyOperationsMapper operationsMapper = new PolicyOperationsMapper(); ObjectMapper mapper = new ObjectMapper(); mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false); mapper.configure(SerializationFeature.FAIL_ON_EMPTY_BEANS, false); PolicyRevokeHandler revokeHandler = new PolicyRevokeHandler(context); try { if (payload != null) { List<org.wso2.iot.agent.beans.Operation> operations = mapper.readValue(payload, mapper.getTypeFactory().constructCollectionType(List.class, org.wso2.iot.agent.beans.Operation.class)); for (org.wso2.iot.agent.beans.Operation op : operations) { op = operationsMapper.getOperation(op); revokeHandler.revokeExistingPolicy(op); } Preference.putString(context, Constants.PreferenceFlag.APPLIED_POLICY, null); } } catch (IOException e) { throw new AndroidAgentException("Error occurred while parsing stream", e); } } /** * Clear client credentials. * @param context - Application context. */ public static void clearClientCredentials(Context context) { Preference.removePreference(context, Constants.CLIENT_ID); Preference.removePreference(context, Constants.CLIENT_SECRET); } /** * Call EMM system app in COPE mode. * @param context - Application context. * @param operation - Operation code. * @param command - Shell command to be executed. * @param appUri - App package/APK URI when an app operation executed. */ public static void callSystemApp(Context context, String operation, String command, String appUri) { if (Constants.SYSTEM_APP_ENABLED) { Intent intent = new Intent(Constants.SYSTEM_APP_SERVICE_START_ACTION); Intent explicitIntent = createExplicitFromImplicitIntent(context, intent); if (explicitIntent != null) { intent = explicitIntent; } intent.putExtra(Constants.OPERATION_CODE, operation); intent.setPackage(Constants.AGENT_PACKAGE); if (appUri != null) { intent.putExtra("appUri", appUri); } if (command != null) { if (Constants.Operation.UPGRADE_FIRMWARE.equals(operation)) { try { JSONObject upgradeData = new JSONObject(command); if (upgradeData .isNull(context.getResources().getString(R.string.firmware_upgrade_automatic_retry)) && Preference.hasPreferenceKey(context, context.getResources().getString(R.string.is_automatic_firmware_upgrade))) { boolean isFirmwareUpgradeAutoRetry = Preference.getBoolean(context, context.getResources().getString(R.string.is_automatic_firmware_upgrade)); upgradeData.put( context.getResources().getString(R.string.firmware_upgrade_automatic_retry), isFirmwareUpgradeAutoRetry); command = upgradeData.toString(); Log.d(TAG, "Updated payload: " + command); } else if (!upgradeData.isNull( context.getResources().getString(R.string.firmware_upgrade_automatic_retry))) { Preference.putBoolean(context, context.getResources().getString(R.string.is_automatic_firmware_upgrade), upgradeData.getBoolean(context.getResources() .getString(R.string.firmware_upgrade_automatic_retry))); } else { upgradeData.put( context.getResources().getString(R.string.firmware_upgrade_automatic_retry), true); Preference.putBoolean(context, context.getResources().getString(R.string.is_automatic_firmware_upgrade), true); Log.d(TAG, "Updated payload: " + command); } } catch (JSONException e) { Log.e(TAG, "Could not parse Firmware upgrade operation", e); } intent.putExtra("operationId", Preference.getInt(context, "firmwareOperationId")); } intent.putExtra("command", command); } context.startServiceAsUser(intent, android.os.Process.myUserHandle()); } else { Log.e(TAG, "System app not enabled."); } } public static void callSystemAppInit(Context context) { if (Constants.SYSTEM_APP_ENABLED) { Intent intent = new Intent(Constants.SYSTEM_APP_SERVICE_START_ACTION); Intent explicitIntent = createExplicitFromImplicitIntent(context, intent); if (explicitIntent != null) { intent = explicitIntent; } context.startServiceAsUser(intent, android.os.Process.myUserHandle()); } else { Log.e(TAG, "System app not enabled."); } } public static boolean isSystemAppInstalled(Context context) { PackageManager packageManager = context.getPackageManager(); boolean systemAppInstalled; try { packageManager.getPackageInfo(Constants.SYSTEM_SERVICE_PACKAGE, PackageManager.GET_ACTIVITIES); systemAppInstalled = true; } catch (PackageManager.NameNotFoundException e) { systemAppInstalled = false; } return systemAppInstalled; } public static Intent createExplicitFromImplicitIntent(Context context, Intent implicitIntent) { //Retrieve all services that can match the given intent PackageManager pm = context.getPackageManager(); List<ResolveInfo> resolveInfo = pm.queryIntentServices(implicitIntent, 0); //Make sure only one match was found if (resolveInfo == null || resolveInfo.size() != 1) { return null; } //Get component info and create ComponentName ResolveInfo serviceInfo = resolveInfo.get(0); String packageName = serviceInfo.serviceInfo.packageName; String className = serviceInfo.serviceInfo.name; ComponentName component = new ComponentName(packageName, className); //Create a new intent. Use the old one for extras and such reuse Intent explicitIntent = new Intent(implicitIntent); //Set the component to be explicit explicitIntent.setComponent(component); return explicitIntent; } public static void registerSystemAppReceiver(Context context) { IntentFilter filter = new IntentFilter(Constants.SYSTEM_APP_BROADCAST_ACTION); filter.addCategory(Intent.CATEGORY_DEFAULT); SystemServiceResponseReceiver receiver = new SystemServiceResponseReceiver(); context.registerReceiver(receiver, filter); } /** * Get installed package list of applications in device * @param context Context object * @return list of installed app packages */ public static List<String> getInstalledAppPackages(Context context) { ApplicationManager applicationManager = new ApplicationManager(context.getApplicationContext()); List<ApplicationInfo> installedApplications = applicationManager.getInstalledApplications(); List<String> installedAppPackages = new ArrayList<>(); for (ApplicationInfo appInfo : installedApplications) { installedAppPackages.add(appInfo.packageName); } return installedAppPackages; } /** * Get installed package list of applications in device by user * @param context Context object * @return list of installed app packages */ public static List<String> getInstalledAppPackagesByUser(Context context) { return new ApplicationManager(context.getApplicationContext()).getInstalledAppsByUser(); } /** * Get package list of applications that are not system apps * * @param context Context object * @return list of package list that are not system apps */ public static List<String> getAppsOfUser(Context context) { return new ApplicationManager(context.getApplicationContext()).getAppsOfUser(); } public static AppRestriction getAppRestrictionTypeAndList(Operation operation, ResultPayload resultBuilder, Resources resources) throws AndroidAgentException { AppRestriction appRestriction = new AppRestriction(); JSONArray permittedApps = null; try { JSONObject payload = new JSONObject(operation.getPayLoad().toString()); appRestriction.setRestrictionType((String) payload.get(Constants.AppRestriction.RESTRICTION_TYPE)); if (!payload.isNull(Constants.AppRestriction.RESTRICTED_APPLICATIONS)) { permittedApps = payload.getJSONArray(Constants.AppRestriction.RESTRICTED_APPLICATIONS); } } catch (JSONException e) { if (resources != null && resultBuilder != null) { operation.setStatus(resources.getString(R.string.operation_value_error)); resultBuilder.build(operation); } throw new AndroidAgentException("Invalid JSON format.", e); } List<String> restrictedPackages = new ArrayList<>(); if (permittedApps != null) { for (int i = 0; i < permittedApps.length(); i++) { try { restrictedPackages.add((String) ((JSONObject) permittedApps.get(i)) .get(Constants.AppRuntimePermission.PACKAGE_NAME)); } catch (JSONException e) { if (resources != null && resultBuilder != null) { operation.setStatus(resources.getString(R.string.operation_value_error)); resultBuilder.build(operation); } throw new AndroidAgentException("Invalid JSON format", e); } } } appRestriction.setRestrictedList(restrictedPackages); return appRestriction; } public static AppRestriction getAppRuntimePermissionTypeAndList(Operation operation, ResultPayload resultBuilder, Resources resources) throws AndroidAgentException { AppRestriction appRestriction = new AppRestriction(); JSONArray restrictedApps = null; try { JSONObject payload = new JSONObject(operation.getPayLoad().toString()); appRestriction.setRestrictionType((String) payload.get(Constants.AppRuntimePermission.PERMISSION_TYPE)); if (!payload.isNull(Constants.AppRuntimePermission.PERMITTED_APPS)) { restrictedApps = payload.getJSONArray(Constants.AppRuntimePermission.PERMITTED_APPS); } } catch (JSONException e) { if (resources != null && resultBuilder != null) { operation.setStatus(resources.getString(R.string.operation_value_error)); resultBuilder.build(operation); } throw new AndroidAgentException("Invalid JSON format.", e); } List<String> restrictedPackages = new ArrayList<>(); if (restrictedApps != null) { for (int i = 0; i < restrictedApps.length(); i++) { try { restrictedPackages.add((String) ((JSONObject) restrictedApps.get(i)) .get(Constants.AppRestriction.PACKAGE_NAME)); } catch (JSONException e) { if (resources != null && resultBuilder != null) { operation.setStatus(resources.getString(R.string.operation_value_error)); resultBuilder.build(operation); } throw new AndroidAgentException("Invalid JSON format", e); } } } appRestriction.setRestrictedList(restrictedPackages); return appRestriction; } public static void saveHostDeatils(Context context, String host) { if (host.contains(PROTOCOL_HTTP)) { String hostWithPort = host.substring(PROTOCOL_HTTP.length(), host.length()); Preference.putString(context.getApplicationContext(), Constants.PreferenceFlag.IP, getHostFromUrl(hostWithPort)); Preference.putString(context.getApplicationContext(), Constants.PreferenceFlag.PROTOCOL, PROTOCOL_HTTP); Preference.putString(context.getApplicationContext(), Constants.PreferenceFlag.PORT, getPortFromUrl(hostWithPort, PROTOCOL_HTTP)); } else if (host.contains(PROTOCOL_HTTPS)) { String hostWithPort = host.substring(PROTOCOL_HTTPS.length(), host.length()); Preference.putString(context.getApplicationContext(), Constants.PreferenceFlag.IP, getHostFromUrl(hostWithPort)); Preference.putString(context.getApplicationContext(), Constants.PreferenceFlag.PROTOCOL, PROTOCOL_HTTPS); Preference.putString(context.getApplicationContext(), Constants.PreferenceFlag.PORT, getPortFromUrl(hostWithPort, PROTOCOL_HTTPS)); } else if (host.contains(COLON)) { Preference.putString(context.getApplicationContext(), Constants.PreferenceFlag.IP, getHostFromUrl(host)); Preference.putString(context.getApplicationContext(), Constants.PreferenceFlag.PORT, getPortFromUrl(host, PROTOCOL_HTTP)); } else { Preference.putString(context.getApplicationContext(), Constants.PreferenceFlag.IP, host); } } public static String getHostFromUrl(String url) { if (url.contains(COLON)) { return url.substring(0, url.indexOf(COLON)); } else { return url; } } public static String getPortFromUrl(String url, String protocol) { if (url.contains(COLON)) { return url.substring((url.indexOf(COLON) + 1), url.length()); } else { if (protocol.equals(PROTOCOL_HTTP)) { return String.valueOf(org.wso2.iot.agent.proxy.utils.Constants.HTTP); } else { return String.valueOf(org.wso2.iot.agent.proxy.utils.Constants.HTTPS); } } } public static boolean isServiceRunning(Context context, Class<?> serviceClass) { ActivityManager manager = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE); for (ActivityManager.RunningServiceInfo service : manager.getRunningServices(Integer.MAX_VALUE)) { if (serviceClass.getName().equals(service.service.getClassName())) { return true; } } return false; } public static Location getLocation(Context context) { Intent serviceIntent = new Intent(context, LocationService.class); context.startService(serviceIntent); return LocationUpdateReceiver.getLocation(); } public static void displayNotification(Context context, int icon, String title, String message, Class<?> sourceActivityClass, String tag, int id) { NotificationCompat.Builder mBuilder = new NotificationCompat.Builder(context); mBuilder.setSmallIcon(icon); mBuilder.setContentTitle(title); mBuilder.setContentText(message); mBuilder.setOngoing(true); mBuilder.setOnlyAlertOnce(true); Intent resultIntent = new Intent(context, sourceActivityClass); TaskStackBuilder stackBuilder = TaskStackBuilder.create(context); stackBuilder.addParentStack(sourceActivityClass); // Adds the Intent that starts the Activity to the top of the stack stackBuilder.addNextIntent(resultIntent); PendingIntent resultPendingIntent = stackBuilder.getPendingIntent(0, PendingIntent.FLAG_UPDATE_CURRENT); mBuilder.setContentIntent(resultPendingIntent); NotificationManager mNotificationManager = (NotificationManager) context .getSystemService(Context.NOTIFICATION_SERVICE); mNotificationManager.notify(tag, id, mBuilder.build()); } public static Date currentDate() { Calendar calendar = Calendar.getInstance(); return calendar.getTime(); } public static String getTimeAgo(long time, Context ctx) { Date curDate = currentDate(); long now = curDate.getTime(); if (time > now || time <= 0) { return null; } int dim = getTimeDistanceInMinutes(time); String timeAgo; if (dim == 0) { timeAgo = ctx.getResources().getString(R.string.date_util_term_less) + " " + ctx.getResources().getString(R.string.date_util_term_a) + " " + ctx.getResources().getString(R.string.date_util_unit_minute); } else if (dim == 1) { timeAgo = dim + ctx.getResources().getString(R.string.date_util_unit_minute); } else if (dim >= 2 && dim <= 44) { timeAgo = dim + " " + ctx.getResources().getString(R.string.date_util_unit_minutes); } else if (dim >= 45 && dim <= 89) { timeAgo = ctx.getResources().getString(R.string.date_util_prefix_about) + " " + ctx.getResources().getString(R.string.date_util_term_an) + " " + ctx.getResources().getString(R.string.date_util_unit_hour); } else if (dim >= 90 && dim <= 1439) { timeAgo = ctx.getResources().getString(R.string.date_util_prefix_about) + " " + (Math.round(dim / 60)) + " " + ctx.getResources().getString(R.string.date_util_unit_hours); } else if (dim >= 1440 && dim <= 2519) { timeAgo = "1 " + ctx.getResources().getString(R.string.date_util_unit_day); } else if (dim >= 2520 && dim <= 43199) { timeAgo = (Math.round(dim / 1440)) + " " + ctx.getResources().getString(R.string.date_util_unit_days); } else if (dim >= 43200 && dim <= 86399) { timeAgo = ctx.getResources().getString(R.string.date_util_prefix_about) + " " + ctx.getResources().getString(R.string.date_util_term_a) + " " + ctx.getResources().getString(R.string.date_util_unit_month); } else if (dim >= 86400 && dim <= 525599) { timeAgo = (Math.round(dim / 43200)) + " " + ctx.getResources().getString(R.string.date_util_unit_months); } else if (dim >= 525600 && dim <= 655199) { timeAgo = ctx.getResources().getString(R.string.date_util_prefix_about) + " " + ctx.getResources().getString(R.string.date_util_term_a) + " " + ctx.getResources().getString(R.string.date_util_unit_year); } else if (dim >= 655200 && dim <= 914399) { timeAgo = ctx.getResources().getString(R.string.date_util_prefix_over) + " " + ctx.getResources().getString(R.string.date_util_term_a) + " " + ctx.getResources().getString(R.string.date_util_unit_year); } else if (dim >= 914400 && dim <= 1051199) { timeAgo = ctx.getResources().getString(R.string.date_util_prefix_almost) + " 2 " + ctx.getResources().getString(R.string.date_util_unit_years); } else { timeAgo = ctx.getResources().getString(R.string.date_util_prefix_about) + " " + (Math.round(dim / 525600)) + " " + ctx.getResources().getString(R.string.date_util_unit_years); } return timeAgo + " " + ctx.getResources().getString(R.string.date_util_suffix); } private static int getTimeDistanceInMinutes(long time) { long timeDistance = currentDate().getTime() - time; return Math.round((Math.abs(timeDistance) / 1000) / 60); } }