Java Client for Google Maps Services

[!TIP]
If you are looking for Java client libraries for the following APIs, see the Google Maps Platform APIs in the Cloud Client Libraries for Java (releases).

• Address Validation API
• Datasets API
• Places API (New)
• Routes API

The new APIs will not be added to this client library.

Description

Use Java? Want to geocode something? Looking for directions?
Maybe matrices of directions? This library brings the Google Maps API Web
Services to your server-side Java application.

The Java Client for Google Maps Services is a Java Client library for the following Google Maps
APIs:

• Directions API
• Distance Matrix API
• Elevation API
• Geocoding API
• Maps Static API
• Places API
• Roads API
• Time Zone API

Requirements

• Java 1.8 or later
• A Cloud project with the relevant API(s) enabled
• An API key associated with the project above

API Key Security

The Java Client for Google Maps Services is designed for use in both server and Android applications.
In either case, it is important to add API key restrictions
to improve the security of your API key. Additional security measures, such as hiding your key
from version control, should also be put in place to further improve the security of your API key.

You can refer to API Security Best Practices to learn
more about this topic.

[!NOTE]
If you are using this library on Android, ensure that your application is using at least version 0.19.0 of this library so that API key restrictions can be enforced.

Installation

You can add the library to your project via Maven or Gradle.

[!NOTE]
Since 0.1.18 there is now a dependency on SLF4J. You need to add one of the adapter dependencies that makes sense for your logging setup. In the configuration samples below we are integrating slf4j-nop, but there are others like slf4j-log4j12 and slf4j-jdk14 that will make more sense in other configurations. This will stop a warning message being emitted when you start using google-maps-services.

Maven

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<dependency>
  <groupId>com.google.maps</groupId>
  <artifactId>google-maps-services</artifactId>
  <version>(insert latest version)</version>
</dependency>
<dependency>
  <groupId>org.slf4j</groupId>
  <artifactId>slf4j-simple</artifactId>
  <version>1.7.25</version>
</dependency>

Gradle

groovyCopy
repositories {
    mavenCentral()
}

dependencies {
    implementation 'com.google.maps:google-maps-services:(insert latest version)'
    implementation 'org.slf4j:slf4j-simple:1.7.25'
}

You can find the latest version at the top of this README or by searching
Maven Central.

Documentation

View the javadoc.

Additional documentation for the included web services is available at
https://developers.google.com/maps/.

• Directions API
• Distance Matrix API
• Elevation API
• Geocoding API
• Maps Static API
• Places API
• Roads API
• Time Zone API

Usage

This example uses the Geocoding API with an API key:

javaCopy
GeoApiContext context = new GeoApiContext.Builder()
    .apiKey("AIza...")
    .build();
GeocodingResponse response =  GeocodingApi.geocode(context,
    "1600 Amphitheatre Parkway Mountain View, CA 94043").await();
Gson gson = new GsonBuilder().setPrettyPrinting().create();
System.out.println(gson.toJson(response.results[0].addressComponents));

// Invoke .shutdown() after your application is done making requests
context.shutdown();

Note: The GeoApiContext is designed to be a Singleton
in your application. Please instantiate one on application startup, and continue to use it for the
life of your application. This will enable proper QPS enforcement across all of your requests.

At the end of the execution, call the shutdown() method of GeoApiContext,
otherwise the thread will remain instantiated in memory.

For more usage examples, check out the tests.

Features

Google App Engine Support

To use Google App Engine with this client library add the latest App Engine dependency
to your build.gradle file:

groovyCopy
dependencies {
    implementation 'com.google.appengine:appengine-api-1.0-sdk:<latest version>'
}

You can then use this client library on Google App Engine with the following code change:

javaCopy
new GeoApiContext.Builder(new GaeRequestHandler.Builder())
    .apiKey("AIza...")
    .build();

The new GaeRequestHandler.Builder() argument to GeoApiContext.Builder's requestHandlerBuilder
tells the Java Client for Google Maps Services to utilise the appropriate calls for making HTTP
requests from Google App Engine, instead of the default OkHttp3
based strategy.

Rate Limiting

Never sleep between requests again! By default, requests are sent at the expected rate limits for
each web service, typically 50 queries per second for free users. If you want to speed up or slow
down requests, you can do that too, using new GeoApiContext.Builder().queryRateLimit(qps).build().
Note that you still need to manually handle the delay between the initial request and successive pages when you're paging through multiple result sets.

Retry on Failure

Automatically retry when intermittent failures occur. That is, when any of the retriable 5xx errors
are returned from the API.

To alter or disable automatic retries, see these methods in GeoApiContext:

• .disableRetries()
• .maxRetries()
• .retryTimeout()
• .setIfExceptionIsAllowedToRetry()

POJOs

Native objects for each of the API responses.

Asynchronous or synchronous -- you choose

All requests support synchronous or asynchronous calling style.

javaCopy
GeocodingApiRequest req = GeocodingApi.newRequest(context).address("Sydney");

// Synchronous
try {
    req.await();
    // Handle successful request.
} catch (Exception e) {
    // Handle error
}

req.awaitIgnoreError(); // No checked exception.

// Async
req.setCallback(new PendingResult.Callback<GeocodingResponse>() {
  @Override
  public void onResult(GeocodingResponse result) {
    // Handle successful request.
  }

  @Override
  public void onFailure(Throwable e) {
    // Handle error.
  }
});

Building the Project

[!NOTE]
You will need an API key to run the tests.

bashCopy
# Compile and package the project
$ ./gradlew jar

# Run the tests
$ ./gradlew test

Terms

This library uses Google Maps Platform services. Use of Google Maps Platform services through this library is subject to the Google Maps Platform Terms of Service.

This library is not a Google Maps Platform Core Service. Therefore, the Google Maps Platform Terms of Service (e.g. Technical Support Services, Service Level Agreements, and Deprecation Policy) do not apply to the code in this library.

Support

This library is offered via an open source license. It is not governed by the Google Maps Platform Support Technical Support Services Guidelines, the SLA, or the Deprecation Policy (however, any Google Maps Platform services used by the library remain subject to the Google Maps Platform Terms of Service).

This library adheres to semantic versioning to indicate when backwards-incompatible changes are introduced. Accordingly, while the library is in version 0.x, backwards-incompatible changes may be introduced at any time.

If you find a bug, or have a feature request, please file an issue on GitHub. If you would like to get answers to technical questions from other Google Maps Platform developers, ask through one of our developer community channels. If you'd like to contribute, please check the Contributing guide in the GitHub repository.