This client library is supported but in maintenance mode only. We are fixing necessary bugs and adding essential features to ensure this library continues to meet your needs for accessing Google APIs. Non-critical issues will be closed. Any issue may be reopened if it is causing ongoing problems.

If you're working with **Google Cloud Platform** APIs such as Datastore, Pub/Sub and many others, consider using the [Cloud Client Libraries for Java](https://github.com/GoogleCloudPlatform/google-cloud-java) instead. These are the new and idiomatic Java libraries targeted specifically at Google Cloud Platform Services.

The Google APIs Client Library for Java is a flexible, efficient, and powerful Java client library for accessing any HTTP-based API on the web, not just Google APIs.

- The core Google APIs Client Library for Java (google-api-java-client), which is the generic runtime library described here. This library provides functionality common to all APIs, for example HTTP transport, error handling, authentication, JSON parsing, media download/upload, and batching.

- An auto-generated Java library for the API you are accessing, for example the [generated Java library for the BigQuery API](https://github.com/google/google-api-java-client-samples/tree/master/bigquery-appengine-sample/src/main/java/com/google/api/client/sample/bigquery/appengine/dashboard). These generated libraries include API-specific information such as the root URL, and classes that represent entities in the context of the API. These classes are useful for making conversions between JSON objects and Java objects.

To find the generated library for a Google API, visit [Google APIs Client Library for Java](https://developers.google.com/api-client-library/java/apis/). The API-specific Java packages include both the core google-api-java-client and the client-specific libraries.

If you are developing for Android and the Google API you want to use is included in the [Google Play Services library](https://developer.android.com/google/play-services/index.html), you should use that library for the best performance and experience.

To access other Google APIs, you can use the Google APIs Client Library for Java, which supports [Android 1.5 (or higher)](https://developers.google.com/api-client-library/java/google-api-java-client/android).

In addition to Android 1.5 or higher, the Google APIs Client Library for Java supports the following Java environments:

- Java 5 (or higher), standard (SE) and enterprise (EE)

- [Google App Engine](https://developers.google.com/api-client-library/java/google-api-java-client/app-engine)

You can call Google APIs using Google service-specific generated libraries with the Google APIs Client Library for Java. Here's an example that makes a call to the [Google Calendar API](https://developers.google.com/google-apps/calendar/):

View.header("Show Calendars");

CalendarList feed = client.calendarList().list().execute();

View.display(feed);

The authentication library can reduce the amount of code needed to handle [OAuth 2.0](https://developers.google.com/api-client-library/java/google-api-java-client/oauth2), and sometimes a few lines is all you need. For example:

```java

/** Authorizes the installed application to access user's protected data. */

private static Credential authorize() throws Exception {

// load client secrets

GoogleClientSecrets clientSecrets = GoogleClientSecrets.load(JSON_FACTORY,

new InputStreamReader(CalendarSample.class.getResourceAsStream("/client_secrets.json")));

// set up authorization code flow

GoogleAuthorizationCodeFlow flow = new GoogleAuthorizationCodeFlow.Builder(

httpTransport, JSON_FACTORY, clientSecrets,

Collections.singleton(CalendarScopes.CALENDAR)).setDataStoreFactory(dataStoreFactory)

.build();

// authorize

return new AuthorizationCodeInstalledApp(flow, new LocalServerReceiver()).authorize("user");

}

```

The library offers helper classes for [batching](https://developers.google.com/api-client-library/java/google-api-java-client/batch), [media upload](https://developers.google.com/api-client-library/java/google-api-java-client/media-upload), and [media download](https://developers.google.com/api-client-library/java/google-api-java-client/media-download).

[App Engine-specific helpers](https://developers.google.com/api-client-library/java/google-api-java-client/app-engine) make quick work of authenticated calls to APIs, and you do not need to worry about exchanging code for tokens. For example:

```java

@Override

protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws IOException {

AppIdentityCredential credential =

new AppIdentityCredential(Arrays.asList(UrlshortenerScopes.URLSHORTENER));

Urlshortener shortener =

new Urlshortener.Builder(new UrlFetchTransport(), new JacksonFactory(), credential)

.build();

UrlHistory history = shortener.URL().list().execute();

...

}

```

If you are developing for Android and the Google API you want to use is included in the [Google Play Services library](https://developer.android.com/google/play-services/index.html), you should use that library for the best performance and experience.

To access other Google APIs, you can use the Google Client Library for Java's Android-specific helper classes, which are are well-integrated with [Android AccountManager](http://developer.android.com/reference/android/accounts/AccountManager.html ). For example:

```java

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

// Google Accounts

credential =

GoogleAccountCredential.usingOAuth2(this, Collections.singleton(TasksScopes.TASKS));

SharedPreferences settings = getPreferences(Context.MODE_PRIVATE);

credential.setSelectedAccountName(settings.getString(PREF_ACCOUNT_NAME, null));

// Tasks client

service =

new com.google.api.services.tasks.Tasks.Builder(httpTransport, jsonFactory, credential)

.setApplicationName("Google-TasksAndroidSample/1.0").build();

}

```

The Google APIs Client Library for Java is easy to install, and you can download the binary directly from the [Downloads page](https://developers.google.com/api-client-library/java/google-api-java-client/download), or you can use Maven or Gradle.

To use Maven, add the following lines to your pom.xml file:

```maven

<project>

<dependencies>

<dependency>

<groupId>com.google.api-client</groupId>

<artifactId>google-api-client</artifactId>

<version>1.23.0</version>

</dependency>

</dependencies>

</project>

```

To use Gradle, add the following lines to your build.gradle file:

This library is built on top of two common libraries, also built by Google, and also designed to work with any HTTP service on the web:

* [Google HTTP Client Library for Java](https://github.com/google/google-http-java-client)

* [Google OAuth Client Library for Java](https://github.com/google/google-oauth-java-client)

Deprecated non-beta features will be removed eighteen months after the release in which they are first deprecated. You must fix your usages before this time. If you don't, any type of breakage might result, and you are not guaranteed a compilation error.