Android studio rest api авторизация

To get the SHA1 fingerprint for your app, run the following command in a terminal:

For example, you’re using a debug-key with Eclipse, then the command looks like this:

Then the keystore password is «android».

The Credentials page then provides the available credentials such as an OAuth 2.0 client ID and an Android Key, but you don’t need these to authorize your Android users. Simply registering your app with the package name and SHA1 makes the Google services accessible by your app.

To acquire the OAuth 2.0 token that will grant you access to Google APIs over HTTP, you need to first identify the user’s Google account with which you’ll query the servers. For this task, the Google Play services library provides a convenient account picker dialog you can invoke using AccountPicker . The result delivered to your activity from the account picker is the account name you’ll use to request the OAuth 2.0 token in the next lesson.

Note: In order to use the APIs discussed here, you must include the Google Play services library with your project. If you haven’t set up your project with the library yet, read the guide to Setup Google Play Services SDK.

Invoke the Account Picker

To open the account picker dialog that’s managed by the Google Play services library, call startActivityForResult() using an Intent returned by AccountPicker.newChooseAccountIntent .

When this code executes, a dialog appears for the user to pick an account. When the user selects the account, your activity receives the result in the onActivityResult() callback.

Most apps should pass the newChooseAccountIntent() method the same arguments shown in the above example, which indicate that:

• There is no currently selected account.
• There is no restricted list of accounts.
• The dialog should list only accounts from the «com.google» domain.
• Don’t prompt the user to pick an account if there’s only one available account (just use that one). However, even if only one account currently exists, the dialog may include an option for the user to add a new account.
• There is no custom title for the dialog.
• There is no specific auth token type required.
• There are no restrictions based on account features.
• There are no authenticator-specific options.

For more details about these arguments, see the newChooseAccountIntent() method documentation.

Retrieve the Account Name

Once the user selects an account, your activity receives a call to its onActivityResult() method. The received Intent includes an extra for KEY_ACCOUNT_NAME , specifying the account name (an email address) you must use to acquire the OAuth 2.0 token.

Here’s an example implementation of the callback onActivityResult() that receives the selected account:

You can now pass the account name held by mEmail to GoogleAuthUtil.getToken() (which is what the getUsername() method does), but because it performs network transactions, this method should not be called from the UI thread. The next lesson shows how to create an AsyncTask to get the auth token on a separate thread.

Once you have retrieved the account name for the user’s Google account, you can call GoogleAuthUtil.getToken() , which returns the access token string required by Google API services.

Calling this method is generally a straightforward procedure, but you must be aware that:

• The GoogleAuthUtil.getToken() method requires a network connection, so your app must acquire the INTERNET permission. You should also check whether the device has a network connection at runtime by querying NetworkInfo , which requires that your app also acquire the ACCESS_NETWORK_STATE permissions—for more details, read Connecting to the Network.
• Because the GoogleAuthUtil.getToken() method performs a synchronous network transaction, you should always perform this call from a worker thread to avoid blocking your app’s UI thread.
• As is true when performing any network transaction, you should be prepared to handle exceptions that may occur. There are also specific exceptions that GoogleAuthUtil.getToken() may throw, defined as GoogleAuthException objects.

This lesson shows how you can gracefully handle these concerns by performing authentication in an AsyncTask and providing users with the appropriate information and available actions during known exceptions.

Note: The code shown in this lesson, using GoogleAuthUtil.getToken() , is appropriate when you will be requesting the OAuth token from an Activity . However, if you need to request the OAuth token from a Service , then you should instead use getTokenWithNotification() . This method works the same as GoogleAuthUtil.getToken() , but if an error occurs, it also creates an appropriate notification that allows the user can recover from the error. The sample available for download above includes code showing how to use this method instead.

Extend AsyncTask to Get the Auth Token

The AsyncTask class provides a simple way to create a worker thread for jobs that should not run on your UI thread. This lesson focuses on how to create such a thread to get your auth token; for a more complete discussion about AsyncTask , read Keeping Your App Responsive and the AsyncTask class reference.

The doInBackground() method in your AsyncTask class is where you should call the GoogleAuthUtil.getToken() method. You can also use it to catch some of the generic exceptions that may occur during your network transactions.

For example, here’s part of an AsyncTask subclass that calls GoogleAuthUtil.getToken() :

In order to call GoogleAuthUtil.getToken() , you must provide the app Context , the account name retrieved from the account picker, and the scope for your auth token request. The above sample code (and the attached sample) defines these arguments with class members that the host activity passes to the AsyncTask class constructor. For more information about setting the scope, see the Specifying Scopes section below.

Note: As shown by the fetchToken() method above, you must handle special exceptions that may occur during the GoogleAuthUtil.getToken() method. The next section shows how you should respond to these exceptions.

Once you have an AsyncTask subclass defined, you can instantiate and execute an instance after you get the user’s account name from the account picker. For example, back in the Activity class you can do something like this:

The pickUserAccount() method is shown in the first lesson, Picking the User’s Account.

For information about how to check whether the device is currently online (as performed by the isDeviceOnline() method above), see the attached sample app or the Connecting to the Network lesson.

The only part left is how you should handle the exceptions that may occur when you call GoogleAuthUtil.getToken() .

Specifying scopes

The scope string is used to specify which Google services can be accessed by an app using the requested auth token. An auth token can be associated with multiple scopes.

When specifying the scopes in your auth token request, prefix the scope string with «oauth2:» followed by a list of one or more OAuth scope values. Use a space to separate each scope value in the list. To see a list of valid OAuth scope values for Google services, browse the OAuth 2.0 Playground.

Tip: Specify «oauth2: » for a single scope. Specify «oauth2: » for multiple scopes (using a space to separate each scope).

For example, to access the Google Books API, the scope is «oauth2:https://www.googleapis.com/auth/books» . To add an additional scope, say for Google+ login, your code might look like this:

Handle Exceptions

As shown in the fetchToken() method above, you must catch all occurrences of GoogleAuthException when you call GoogleAuthUtil.getToken() .

To provide users information and a proper solution to issues that may occur while acquiring the auth token, it’s important that you properly handle the following subclasses of GoogleAuthException :

UserRecoverableAuthException This is an error that users can resolve through some verification. For example, users may need to confirm that your app is allowed to access their Google data or they may need to re-enter their account password. When you receive this exception, call getIntent() on the instance and pass the returned Intent to startActivityForResult() to give users the opportunity to solve the problem, such as by logging in. GooglePlayServicesAvailabilityException This is a specific type of UserRecoverableAuthException indicating that the user’s current version of Google Play services is outdated. Although the recommendation above for UserRecoverableAuthException also works for this exception, calling startActivityForResult() will immediately send users to Google Play Store to install an update, which may be confusing. So you should instead call getConnectionStatusCode() and pass the result to GooglePlayServicesUtil.getErrorDialog() . This returns a Dialog that includes an appropriate message and a button to take users to Google Play Store so they can install an update.

For example, the fetchToken() method in the above sample code catches any occurrence of UserRecoverableAuthException and passes it back to the activity with a method called handleException() . Here’s what that method in the activity may look like:

Notice that in both cases, the REQUEST_CODE_RECOVER_FROM_PLAY_SERVICES_ERROR request code is passed with the request to handle the exception with a dialog or activity. This way, when the user completes the appropriate action to resolve the exception, your onActivityResult() method receives an intent that includes this request code and you can try to acquire the auth token again.

For example, the following code is a complete implementation of onActivityResult() that handles results for both the REQUEST_CODE_PICK_ACCOUNT action (shown in the previous lesson, Picking the User’s Account) and the REQUEST_CODE_RECOVER_FROM_PLAY_SERVICES_ERROR action, which occurs after the user completes one of the actions above to resolve an exception.

For a complete set of code that acquires the OAuth token and queries a Google service over HTTP (including how to use getTokenWithNotification() when you need to acquire the token from a Service ), see the sample app available for download at the top of this page.

Источник

Блог Виктора Деревянко

О жизни, о программировании. Все публикуемые исходные коды можно взять здесь

пятница, 24 января 2014 г.

REST под Android. Часть 2: разрабатываем API

Прежде чем переходить к разработке тестового проекта на RoboSpice, необходимо определиться с API для тестового проекта. Разумеется, можно взять одно из готовых API — благо их сейчас сотни. Однако гораздо интереснее написать свое, тем более, что это нетривиальный процесс. Рассмотрим, как пишутся REST API, какие инструменты для этого существуют, и попробуем реализовать простейшее тестовое API.

Принципы разработки REST API

Apigee

Там же на отдельной странице собраны примеры готовых REST API (github, twitter и т.д.). Специальная консоль позволяет поработать с выбранным API прямо из браузера.

Другие ресурсы

• Книга RESTful Web APIs (2013) by Leonard Richardson, Mike Amundsen, Sam Ruby.
• REST+JSON API Design — Best Practices for Developers: slides, video
• Best Practices for Designing a Pragmatic RESTful API by Vinay Sahni
• REST and JSON API guidelines and best practices by Niels Krijger — удобная шпаргалка, краткая компиляция из других источников.
• HTTP: The Definitive Guide by David Gourley, Brian Totty, Marjorie Sayer, Anshu Aggarwal, Sailu Reddy. В книге детально рассмотрен HTTP протокол, на котором в большинстве случаев реализуются REST API. Так же HTTP посвящена отдельная глава «HTTP for APIs» в книге «RESTful Web APIs».

Тестовый пример: набор книг

Первая попытка описания API: список URL в текстовом файле

Договоримся, что для формат представления ресурсов можно задавать следующим образом:

Теперь зафиксируем способ обработки ошибок. Будем считать, что в случае успеха сервер возвращает код 200 — OK , в случае ошибки один из следующих кодов: 400 — Bad Request, 500 — Internal Server Error . Для наших целей вполне достаточно, хотя можно задействовать и другие коды.

В случае ошибки сервер обязан вернуть сообщение с расшифровкой ошибки в формате:

Осталось описать формат представления ресурса и списков ресурсов.

• [1] получить полный список книг
• [2] получить информацию о книге
• [3] добавить книгу в набор
• [4] удалить книгу из набора
• [5] редактировать информацию о книге
• [6] провести поиск книг по автору, по названию — аналогично [1]

Инструменты для описания API

Вторая попытка описания API: Apiary.io

В целом, работа с API Blueprint Language не вызвала каких-то особых проблем. Смутил только один момент, с которым так и не удалось разобраться. Я создал ресурс Book: и действия к нему Параметр fields может использоваться только с GET, а в PATCN и DELETE его быть не может. Набор параметров я задаю отдельно для каждого действия. Тем не менее, в документации для Edit и Delete параметр fields присутствует в URL, что несколько сбивает с толку. Причем ниже, в списке возможных параметров, он отсутствует.

Выводы

• Прежде чем разрабатывать собственное REST API, имеет смысл ознакомиться как минимум с Web API Design. Crafting Interfaces that Developers Love (pdf), чтобы не наделать грубых ошибок.
• Сервис apiary.io — весьма функционален. Разрабатывать REST API на нем гораздо удобнее, чем в просто фиксировать список URL в текстовом файле. Возможность проверки реализации на соответствие спецификации и Mock-сервер стоят того, чтобы потратить время на изучение API Blueprint Language.

Цель достигнута — BooksSet REST API для тестового проекта создано. Переходим к разработке проекта. Об этом — в следующий раз.

Mindmap, созданный в процессе работы над этой статьей, можно скачать здесь, в формате Freemind 1.0 (портативная версия: freemind-bin-1.0.0.zip).

Update Mock-сервер Apiary не поддерживает компрессию gzip. Может когда-нибудь сделают, особенно если за эту функцию проголосует достаточное количество пользователей.

Источник