FcmJava is a library for working with the Firebase Cloud Messaging (FCM) API.
You can add the following dependencies to your pom.xml to include FcmJava in your project.
<dependency>
<groupId>de.bytefish.fcmjava</groupId>
<artifactId>fcmjava-core</artifactId>
<version>2.1</version>
</dependency>
<dependency>
<groupId>de.bytefish.fcmjava</groupId>
<artifactId>fcmjava-client</artifactId>
<version>2.1</version>
</dependency>The Quickstart shows you how to work with FcmJava.
// Copyright (c) Philipp Wagner. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.
package de.bytefish.fcmjava.integration;
import com.fasterxml.jackson.annotation.JsonProperty;
import de.bytefish.fcmjava.client.FcmClient;
import de.bytefish.fcmjava.constants.Constants;
import de.bytefish.fcmjava.http.options.IFcmClientSettings;
import de.bytefish.fcmjava.model.options.FcmMessageOptions;
import de.bytefish.fcmjava.model.topics.Topic;
import de.bytefish.fcmjava.requests.topic.TopicUnicastMessage;
import org.junit.Ignore;
import org.junit.Test;
import java.nio.charset.Charset;
import java.time.Duration;
public class FcmClientIntegrationTest {
private class PersonData {
private final String firstName;
private final String lastName;
public PersonData(String firstName, String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
@JsonProperty("firstName")
public String getFirstName() {
return firstName;
}
@JsonProperty("lastName")
public String getLastName() {
return lastName;
}
}
@Test
@Ignore("This is an Integration Test using system properties to contact the FCM Server")
public void SendTopicMessageTest() throws Exception {
// Create the Client using system-properties-based settings:
try (FcmClient client = new FcmClient(PropertiesBasedSettings.createFromDefault())) {
// Message Options:
FcmMessageOptions options = FcmMessageOptions.builder()
.setTimeToLive(Duration.ofHours(1))
.build();
// Send a Message:
TopicMessageResponse response = client.send(new TopicUnicastMessage(options, new Topic("news"), new PersonData("Philipp", "Wagner")));
// Assert Results:
Assert.assertNotNull(response);
// Make sure there are no errors:
Assert.assertNotNull(response.getMessageId());
Assert.assertNull(response.getErrorCode());
}
}
}The FcmClient can be instantiated with IFcmClientSettings to supply the API Key. By default the FcmClient uses the
PropertiesBasedSettings, which locate the settings in a default location. If you need to supply the API Key in a different
way, you can simply instantiate the FcmClient with a custom IFcmClientSettings implementation.
By default the FCM API Key is read from an external .properties file called fcmjava.properties to ensure the API Key
secret does not reside in code or leaks into the public. The default location of the fcmjava.properties is
System.getProperty("user.home") + "/.fcmjava/fcmjava.properties".
The file has to contain the FCM API Endpoint and the API Key:
fcm.api.url=https://fcm.googleapis.com/fcm/send
fcm.api.key=<YOUR_API_KEY_HERE>If the properties are available in the default location you can simply instantiate the FcmClientas seen in the example.
You can use the PropertiesBasedSettings class to read the Properties and pass them into the FcmClient, if the Properties path differs from the default path:
PropertiesBasedSettings.createFromDefault()- Uses the default file location of
System.getProperty("user.home") + "/.fcmjava/fcmjava.properties"to read the properties. This is the recommended way of reading your API Key.
- Uses the default file location of
PropertiesBasedSettings.createFromFile(Path path, Charset charset)- Uses a custom file location to read the settings from.
PropertiesBasedSettings.createFromSystemProperties()- Uses the System Properties to initialize the settings.
PropertiesBasedSettings.createFromProperties(Properties properties)- Uses the supplied Properties to build the FcmSettings.
It's not neccessary to use the PropertiesBasedSettings for supplying an API Key to the FcmClient. You can easily implement the IFcmClientSettings interface
and pass it into the FcmClient.
The following test shows a simple IFcmClientSettings implementation, that will be instantiated with the given API Key. Again I strongly suggest to not hardcode the
Firebase Cloud Messaging API Key in code. This makes it possible to accidentally leak your credentials into public.
// Copyright (c) Philipp Wagner. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.
package de.bytefish.fcmjava.client.tests.settings;
import de.bytefish.fcmjava.client.FcmClient;
import de.bytefish.fcmjava.constants.Constants;
import de.bytefish.fcmjava.http.client.IFcmClient;
import de.bytefish.fcmjava.http.options.IFcmClientSettings;
import org.junit.Test;
class FixedFcmClientSettings implements IFcmClientSettings {
private final String apiKey;
public FixedFcmClientSettings(String apiKey) {
this.apiKey = apiKey;
}
@Override
public String getFcmUrl() {
return Constants.FCM_URL;
}
@Override
public String getApiKey() {
return apiKey;
}
}
public class FcmClientSettingsTest {
@Test
public void testFixedClientSettings() {
// Construct the FCM Client Settings with your API Key:
IFcmClientSettings clientSettings = new FixedFcmClientSettings("your_api_key_here");
// Instantiate the FcmClient with the API Key:
IFcmClient client = new FcmClient(clientSettings);
}
}FcmJava uses Apache HttpClient for making requests to the Firebase Cloud Messaging server. So in order to configure
a proxy for the HTTP requests, you can configure the HttpClientBuilder used in FcmJava. This is done by instantiating
the DefaultHttpClient with your configured HttpClientBuilder.
The following test shows how to build the FcmClient with a custom HttpClient, which configures a Proxy for the HttpClientBuilder.
// Copyright (c) Philipp Wagner. All rights reserved.
// Licensed under the MIT license. See LICENSE file in the project root for full license information.
package de.bytefish.fcmjava.client.tests;
import de.bytefish.fcmjava.client.FcmClient;
import de.bytefish.fcmjava.client.http.apache.DefaultHttpClient;
import de.bytefish.fcmjava.http.client.IFcmClient;
import de.bytefish.fcmjava.http.options.IFcmClientSettings;
import org.apache.http.HttpHost;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.impl.client.ProxyAuthenticationStrategy;
import org.junit.Test;
class FakeFcmClientSettings implements IFcmClientSettings {
@Override
public String getFcmUrl() {
return "";
}
@Override
public String getApiKey() {
return "";
}
}
public class HttpBuilderConfigurationTest {
@Test
public void testFcmClientWithProxySettings() {
// Create Settings:
IFcmClientSettings settings = new FakeFcmClientSettings();
// Define the Credentials to be used:
BasicCredentialsProvider basicCredentialsProvider = new BasicCredentialsProvider();
// Set the Credentials (any auth scope used):
basicCredentialsProvider.setCredentials(AuthScope.ANY, new UsernamePasswordCredentials("your_username", "your_password"));
// Create the Apache HttpClientBuilder:
HttpClientBuilder httpClientBuilder = HttpClientBuilder.create()
// Set the Proxy Address:
.setProxy(new HttpHost("your_hostname", 1234))
// Set the Authentication Strategy:
.setProxyAuthenticationStrategy(new ProxyAuthenticationStrategy())
// Set the Credentials Provider we built above:
.setDefaultCredentialsProvider(basicCredentialsProvider);
// Create the DefaultHttpClient:
DefaultHttpClient httpClient = new DefaultHttpClient(settings, httpClientBuilder);
// Finally build the FcmClient:
IFcmClient client = new FcmClient(settings, httpClient);
}
}I have decided to clone the messaging quickstart sample of Google, which is available at:
Now first subscribe to the news topic, then execute the above FcmJava application.
The Android app will now receive a message with the sent data included:
09-17 21:10:45.250 10882-11300/com.google.firebase.quickstart.fcm D/MyFirebaseMsgService: From: /topics/news
09-17 21:10:45.251 10882-11300/com.google.firebase.quickstart.fcm D/MyFirebaseMsgService: Message data payload: {lastName=Wagner, firstName=Philipp}