BAEL-5900: Using Firebase Cloud Messaging in SpringBoot Applications (#13102)

* [BAEL-4849] Article code

* [BAEL-4968] Article code

* [BAEL-4968] Article code

* [BAEL-4968] Article code

* [BAEL-4968] Remove extra comments

* [BAEL-5258] Article Code

* [BAEL-2765] PKCE Support for Secret Clients

* [BAEL-5698] Article code

* [BAEL-5698] Article code

* [BAEL-5900] Initial commit

gcp-firebase/.gitignore

@@ -0,0 +1 @@
+/firebase-service-account.json

gcp-firebase/pom.xml

@@ -0,0 +1,48 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-boot-2</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../parent-boot-2</relativePath>
+    </parent>
+  <artifactId>gcp-firebase</artifactId>
+  
+  <properties>
+    <firebase-admin.version>9.1.1</firebase-admin.version>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>com.google.firebase</groupId>
+      <artifactId>firebase-admin</artifactId>
+      <version>${firebase-admin.version}</version>
+    </dependency>
+    
+    
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-web</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-test</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-configuration-processor</artifactId>
+        <optional>true</optional>
+    </dependency>
+  </dependencies>
+  
+  
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
+      </plugin>
+    </plugins>
+  </build>
+</project>

gcp-firebase/src/main/java/com/baeldung/gcp/firebase/publisher/FirebasePublisherApplication.java

@@ -0,0 +1,12 @@
+package com.baeldung.gcp.firebase.publisher;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class FirebasePublisherApplication {
+
+    public static void main(String[] args ) {
+        SpringApplication.run(FirebasePublisherApplication.class,args);
+    }
+}

gcp-firebase/src/main/java/com/baeldung/gcp/firebase/publisher/config/FirebaseConfiguration.java

@@ -0,0 +1,57 @@
+package com.baeldung.gcp.firebase.publisher.config;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import com.google.api.client.http.HttpTransport;
+import com.google.auth.oauth2.GoogleCredentials;
+import com.google.firebase.FirebaseApp;
+import com.google.firebase.FirebaseOptions;
+import com.google.firebase.messaging.FirebaseMessaging;
+
+@Configuration
+@EnableConfigurationProperties(FirebaseProperties.class)
+public class FirebaseConfiguration {
+
+    private final FirebaseProperties firebaseProperties;
+
+    public FirebaseConfiguration(FirebaseProperties firebaseProperties) {
+        this.firebaseProperties = firebaseProperties;
+    }
+
+    @Bean
+    GoogleCredentials googleCredentials() {
+        try {
+            if (firebaseProperties.getServiceAccount() != null) {
+                try( InputStream is = firebaseProperties.getServiceAccount().getInputStream()) {
+                    return GoogleCredentials.fromStream(is);
+                }                
+            } 
+            else {
+                // Use standard credentials chain. Useful when running inside GKE
+                return GoogleCredentials.getApplicationDefault();
+            }
+        } 
+        catch (IOException ioe) {
+            throw new RuntimeException(ioe);
+        }
+    }
+
+    @Bean
+    FirebaseApp firebaseApp(GoogleCredentials credentials) {
+        FirebaseOptions options = FirebaseOptions.builder()
+          .setCredentials(credentials)
+          .build();
+
+        return FirebaseApp.initializeApp(options);
+    }
+
+    @Bean
+    FirebaseMessaging firebaseMessaging(FirebaseApp firebaseApp) {
+        return FirebaseMessaging.getInstance(firebaseApp);
+    }
+}

gcp-firebase/src/main/java/com/baeldung/gcp/firebase/publisher/config/FirebaseProperties.java

@@ -0,0 +1,25 @@
+package com.baeldung.gcp.firebase.publisher.config;
+
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.core.io.Resource;
+
+@ConfigurationProperties(prefix = "gcp.firebase")
+public class FirebaseProperties {
+    private Resource serviceAccount;
+    
+
+    /**
+     * @return the serviceAccount
+     */
+    public Resource getServiceAccount() {
+        return serviceAccount;
+    }
+
+    /**
+     * @param serviceAccount the serviceAccount to set
+     */
+    public void setServiceAccount(Resource serviceAccount) {
+        this.serviceAccount = serviceAccount;
+    }
+
+}

gcp-firebase/src/main/java/com/baeldung/gcp/firebase/publisher/controller/ConditionMessageRepresentation.java

@@ -0,0 +1,35 @@
+package com.baeldung.gcp.firebase.publisher.controller;
+
+public class ConditionMessageRepresentation {
+    
+    private String condition;
+    private String data;
+    
+    /**
+     * @return the condition
+     */
+    public String getCondition() {
+        return condition;
+    }
+
+    /**
+     * @param condition the condition to set
+     */
+    public void setCondition(String condition) {
+        this.condition = condition;
+    }
+
+    /**
+     * @return the data
+     */
+    public String getData() {
+        return data;
+    }
+
+    /**
+     * @param data the data to set
+     */
+    public void setData(String data) {
+        this.data = data;
+    }
+}

gcp-firebase/src/main/java/com/baeldung/gcp/firebase/publisher/controller/FirebasePublisherController.java

@@ -0,0 +1,109 @@
+package com.baeldung.gcp.firebase.publisher.controller;
+
+
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import com.google.firebase.messaging.AndroidConfig;
+import com.google.firebase.messaging.AndroidFcmOptions;
+import com.google.firebase.messaging.ApnsConfig;
+import com.google.firebase.messaging.BatchResponse;
+import com.google.firebase.messaging.FcmOptions;
+import com.google.firebase.messaging.FirebaseMessaging;
+import com.google.firebase.messaging.FirebaseMessagingException;
+import com.google.firebase.messaging.Message;
+import com.google.firebase.messaging.MulticastMessage;
+import com.google.firebase.messaging.Notification;
+
+@RestController
+public class FirebasePublisherController {
+    
+    private final FirebaseMessaging fcm;
+    
+    public FirebasePublisherController(FirebaseMessaging fcm) {
+        this.fcm = fcm;        
+    }
+
+    @PostMapping("/topics/{topic}")
+    public ResponseEntity<String> postToTopic(@RequestBody String message, @PathVariable("topic") String topic) throws FirebaseMessagingException {
+        
+        Message msg = Message.builder()
+          .setTopic(topic)
+          .putData("body", message)
+          .build();
+
+        String id = fcm.send(msg);
+        return ResponseEntity
+          .status(HttpStatus.ACCEPTED)
+          .body(id);        
+    }
+    
+    @PostMapping("/condition")
+    public ResponseEntity<String> postToCondition(@RequestBody ConditionMessageRepresentation message ) throws FirebaseMessagingException {
+        
+        Message msg = Message.builder()
+          .setCondition(message.getCondition())
+          .putData("body", message.getData())
+          .build();
+
+        String id = fcm.send(msg);
+        return ResponseEntity
+          .status(HttpStatus.ACCEPTED)
+          .body(id);        
+    }
+    
+    
+    @PostMapping("/clients/{registrationToken}")
+    public ResponseEntity<String> postToClient(@RequestBody String message, @PathVariable("registrationToken") String registrationToken) throws FirebaseMessagingException {
+        
+        Message msg = Message.builder()
+          .setToken(registrationToken)
+          .putData("body", message)
+          .build();
+
+        String id = fcm.send(msg);
+        return ResponseEntity
+          .status(HttpStatus.ACCEPTED)
+          .body(id);        
+    }
+    
+    @PostMapping("/clients")
+    public ResponseEntity<List<String>> postToClients(@RequestBody MulticastMessageRepresentation message) throws FirebaseMessagingException {
+        
+        MulticastMessage msg = MulticastMessage.builder()
+          .addAllTokens(message.getRegistrationTokens())
+          .putData("body", message.getData())
+          .build();
+
+        BatchResponse response = fcm.sendMulticast(msg);
+        
+        List<String> ids = response.getResponses()
+          .stream()
+          .map(r->r.getMessageId())
+          .collect(Collectors.toList());
+        
+        return ResponseEntity
+          .status(HttpStatus.ACCEPTED)
+          .body(ids);        
+    }    
+    
+    @PostMapping("/subscriptions/{topic}")
+    public ResponseEntity<Void> createSubscription(@PathVariable("topic") String topic,@RequestBody List<String> registrationTokens) throws FirebaseMessagingException {        
+        fcm.subscribeToTopic(registrationTokens, topic);        
+        return ResponseEntity.ok().build();        
+    }
+    
+    @DeleteMapping("/subscriptions/{topic}/{registrationToken}")
+    public ResponseEntity<Void> deleteSubscription(@PathVariable String topic, @PathVariable String registrationToken) throws FirebaseMessagingException {
+        fcm.subscribeToTopic(List.of(registrationToken), topic);        
+        return ResponseEntity.ok().build();        
+    }
+}

gcp-firebase/src/main/java/com/baeldung/gcp/firebase/publisher/controller/MulticastMessageRepresentation.java

@@ -0,0 +1,33 @@
+package com.baeldung.gcp.firebase.publisher.controller;
+
+import java.util.List;
+
+public class MulticastMessageRepresentation {
+    
+    private String data;
+    private List<String> registrationTokens;
+    /**
+     * @return the message
+     */
+    public String getData() {
+        return data;
+    }
+    /**
+     * @param message the message to set
+     */
+    public void setData(String data) {
+        this.data = data;
+    }
+    /**
+     * @return the registrationTokens
+     */
+    public List<String> getRegistrationTokens() {
+        return registrationTokens;
+    }
+    /**
+     * @param registrationTokens the registrationTokens to set
+     */
+    public void setRegistrationTokens(List<String> registrationTokens) {
+        this.registrationTokens = registrationTokens;
+    }
+}

gcp-firebase/src/main/resources/application.properties

@@ -0,0 +1,2 @@
+# Service account location. Can be a filesystem path or a classpath resource
+gcp.firebase.service-account=file:firebase-service-account.json

gcp-firebase/src/test/java/com/baeldung/gcp/firebase/publisher/controller/FirebasePublisherControllerLiveTest.java

@@ -0,0 +1,48 @@
+package com.baeldung.gcp.firebase.publisher.controller;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import java.net.URI;
+import java.util.Map;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.boot.test.web.client.TestRestTemplate;
+import org.springframework.boot.test.web.server.LocalServerPort;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+
+@SpringBootTest(webEnvironment = WebEnvironment.RANDOM_PORT)
+class FirebasePublisherControllerLiveTest {
+    
+    @LocalServerPort
+    int serverPort;
+    
+    @Autowired
+    TestRestTemplate restTemplate;
+
+    @Test
+    void testWhenPostTopicMessage_thenSucess() throws Exception{
+        
+        URI uri = new URI("http://localhost:" + serverPort + "/topics/my-topic");
+        ResponseEntity<String> response = restTemplate.postForEntity(uri, "Hello, world", String.class);
+        
+        assertNotNull(response);
+        assertEquals(HttpStatus.ACCEPTED, response.getStatusCode());
+        assertNotNull(response.getBody());        
+    }
+
+    @Test
+    void testWhenPostClientMessage_thenSucess() throws Exception{
+        
+        URI uri = new URI("http://localhost:" + serverPort + "/clients/fake-registration1");
+        ResponseEntity<String> response = restTemplate.postForEntity(uri, "Hello, world", String.class);
+        
+        assertNotNull(response);
+        assertEquals(HttpStatus.ACCEPTED, response.getStatusCode());
+        assertNotNull(response.getBody());        
+    }
+    
+}

messaging-modules/rabbitmq/README.md

@@ -8,3 +8,4 @@ This module contains articles about RabbitMQ.
 - [Pub-Sub vs. Message Queues](https://www.baeldung.com/pub-sub-vs-message-queues)
 - [Channels and Connections in RabbitMQ](https://www.baeldung.com/java-rabbitmq-channels-connections)
 
+