Spring Boot with Apache Pulsar (#14341)

* Add dead-letter configuration with code refactor

* Add String consumer

* Add customizers in message producers

* Reindent PulsarConsumer.java

* Reindent PulsarProducer.java

* Reindent pom.xml and remove readme

* Update log in PulsarConsumer

* Re-indent main class and remove test directory

spring-pulsar/src/main/java/com/baeldung/springpulsar/PulsarConsumer.java

@@ -0,0 +1,59 @@
+package com.baeldung.springpulsar;
+
+import org.apache.pulsar.client.api.DeadLetterPolicy;
+import org.apache.pulsar.client.api.SubscriptionType;
+import org.apache.pulsar.common.schema.SchemaType;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.context.annotation.Bean;
+import org.springframework.pulsar.annotation.PulsarListener;
+import org.springframework.pulsar.listener.AckMode;
+import org.springframework.stereotype.Service;
+
+@Service
+public class PulsarConsumer {
+
+    private static final String STRING_TOPIC = "string-topic";
+    private static final String USER_TOPIC = "user-topic";
+    private static final String USER_DEAD_LETTER_TOPIC = "user-dead-letter-topic";
+    private final Logger LOGGER = LoggerFactory.getLogger(PulsarConsumer.class);
+
+    @PulsarListener(
+      subscriptionName = "string-topic-subscription",
+      topics = STRING_TOPIC,
+      subscriptionType = SubscriptionType.Shared
+    )
+    public void stringTopicListener(String str) {
+        LOGGER.info("Received String message: {}", str);
+    }
+
+    @Bean
+    DeadLetterPolicy deadLetterPolicy() {
+        return DeadLetterPolicy.builder()
+          .maxRedeliverCount(10)
+          .deadLetterTopic(USER_DEAD_LETTER_TOPIC)
+          .build();
+    }
+
+    @PulsarListener(
+      subscriptionName = "user-topic-subscription",
+      topics = USER_TOPIC,
+      subscriptionType = SubscriptionType.Shared,
+      schemaType = SchemaType.JSON,
+      ackMode = AckMode.RECORD,
+      deadLetterPolicy = "deadLetterPolicy",
+      properties = {"ackTimeout=60s"}
+    )
+    public void userTopicListener(User user) {
+        LOGGER.info("Received user object with email: {}", user.getEmail());
+    }
+
+    @PulsarListener(
+      subscriptionName = "dead-letter-topic-subscription",
+      topics = USER_DEAD_LETTER_TOPIC,
+      subscriptionType = SubscriptionType.Shared
+    )
+    public void userDlqTopicListener(User user) {
+        LOGGER.info("Received user object in user-DLQ with email: {}", user.getEmail());
+    }
+}

spring-pulsar/src/main/java/com/baeldung/springpulsar/PulsarProducer.java

@@ -0,0 +1,37 @@
+package com.baeldung.springpulsar;
+
+import org.apache.pulsar.client.api.ProducerAccessMode;
+import org.apache.pulsar.client.api.PulsarClientException;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.pulsar.core.PulsarTemplate;
+import org.springframework.stereotype.Component;
+
+import java.util.concurrent.TimeUnit;
+
+@Component
+public class PulsarProducer {
+
+    @Autowired
+    private PulsarTemplate<User> template;
+    @Autowired
+    private PulsarTemplate<String> stringTemplate;
+
+    private static final String USER_TOPIC = "user-topic";
+    private static final String USER_TOPIC_STR = "string-topic";
+
+    public void sendMessageToPulsarTopic(User user) throws PulsarClientException {
+        template.newMessage(user)
+          .withProducerCustomizer(pc -> {
+              pc.accessMode(ProducerAccessMode.Shared);
+          })
+          .withMessageCustomizer(mc -> {
+              mc.deliverAfter(10L, TimeUnit.SECONDS);
+          })
+          .withTopic(USER_TOPIC)
+          .send();
+    }
+
+    public void sendStringMessageToPulsarTopic(String str) throws PulsarClientException {
+        stringTemplate.send(USER_TOPIC_STR, str);
+    }
+}

spring-pulsar/src/main/java/com/baeldung/springpulsar/SpringPulsarApplication.java

@@ -0,0 +1,15 @@
+package com.baeldung.springpulsar;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.pulsar.annotation.EnablePulsar;
+
+@EnablePulsar
+@SpringBootApplication
+public class SpringPulsarApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(SpringPulsarApplication.class, args);
+    }
+
+}

spring-pulsar/src/main/java/com/baeldung/springpulsar/User.java

@@ -0,0 +1,31 @@
+package com.baeldung.springpulsar;
+
+public class User {
+
+    private String email;
+    private String firstName;
+
+    public User() {
+    }
+
+    public User(String email, String firstName) {
+        this.email = email;
+        this.firstName = firstName;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    public String getFirstName() {
+        return firstName;
+    }
+
+    public void setFirstName(String firstName) {
+        this.firstName = firstName;
+    }
+}

spring-pulsar/src/main/resources/application.yaml

@@ -0,0 +1,12 @@
+server:
+  port: 8085
+
+spring:
+  pulsar:
+    client:
+      service-url: pulsar://localhost:6650
+    defaults:
+      type-mappings:
+        - message-type: com.baeldung.springpulsar.User
+          schema-info:
+            schema-type: JSON