BAEL-4908 added code for pubsub vs message queues tutorial

rabbitmq/src/main/java/com/baeldung/pubsubmq/client/ClientApplication.java

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+package com.baeldung.pubsubmq.client;
+
+import org.springframework.amqp.core.Queue;
+import org.springframework.amqp.rabbit.connection.ConnectionFactory;
+import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer;
+import org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+
+@SpringBootApplication
+public class ClientApplication {
+    private static final String MESSAGE_QUEUE = "pizza-message-queue";
+
+    @Bean
+    public Queue queue() {
+        return new Queue(MESSAGE_QUEUE);
+    }
+
+    @Bean
+    public SimpleMessageListenerContainer container(ConnectionFactory connectionFactory, MessageListenerAdapter listenerAdapter) {
+        SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
+        container.setConnectionFactory(connectionFactory);
+        container.setQueueNames(MESSAGE_QUEUE);
+        container.setMessageListener(listenerAdapter);
+        return container;
+    }
+
+    @Bean
+    public Consumer consumer() {
+        return new Consumer();
+    }
+
+    @Bean
+    public MessageListenerAdapter listenerAdapter(Consumer consumer) {
+        return new MessageListenerAdapter(consumer, "receiveOrder");
+    }
+
+    public static void main(String[] args) {
+        SpringApplication.run(ClientApplication.class, args);
+    }
+}

rabbitmq/src/main/java/com/baeldung/pubsubmq/client/Consumer.java

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+package com.baeldung.pubsubmq.client;
+
+public class Consumer {
+    public void receiveOrder(String message) {
+        System.out.printf("Order received: %s%n", message);
+    }
+}

rabbitmq/src/main/java/com/baeldung/pubsubmq/server/Publisher.java

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+package com.baeldung.pubsubmq.server;
+
+import org.springframework.amqp.rabbit.core.RabbitTemplate;
+
+import javax.annotation.PostConstruct;
+
+public class Publisher {
+
+    private RabbitTemplate rabbitTemplate;
+    private String queue;
+    private String topic;
+
+    public Publisher(RabbitTemplate rabbitTemplate, String queue, String topic) {
+        this.rabbitTemplate = rabbitTemplate;
+        this.queue = queue;
+        this.topic = topic;
+    }
+
+    @PostConstruct
+    public void postMessages() {
+        rabbitTemplate.convertAndSend(queue, "1 Pepperoni");
+        rabbitTemplate.convertAndSend(queue, "3 Margarita");
+        rabbitTemplate.convertAndSend(queue, "1 Ham and Pineapple (yuck)");
+
+        rabbitTemplate.convertAndSend(topic, "notification", "New Deal on T-Shirts: 95% off!");
+        rabbitTemplate.convertAndSend(topic, "notification", "2 for 1 on all Jeans!");
+    }
+}

rabbitmq/src/main/java/com/baeldung/pubsubmq/server/ServerApplication.java

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+package com.baeldung.pubsubmq.server;
+
+import org.springframework.amqp.core.Binding;
+import org.springframework.amqp.core.BindingBuilder;
+import org.springframework.amqp.core.Queue;
+import org.springframework.amqp.core.TopicExchange;
+import org.springframework.amqp.rabbit.core.RabbitTemplate;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+@SpringBootApplication
+public class ServerApplication {
+    private static final String MESSAGE_QUEUE = "pizza-message-queue";
+    private static final String PUB_SUB_TOPIC = "notification-topic";
+    private static final String PUB_SUB_EMAIL_QUEUE = "email-queue";
+    private static final String PUB_SUB_TEXT_QUEUE = "text-queue";
+
+    @Bean
+    public Queue queue() {
+        return new Queue(MESSAGE_QUEUE);
+    }
+
+    @Bean
+    public Queue emailQueue() {
+        return new Queue(PUB_SUB_EMAIL_QUEUE);
+    }
+
+    @Bean
+    public Queue textQueue() {
+        return new Queue(PUB_SUB_TEXT_QUEUE);
+    }
+
+    @Bean
+    public TopicExchange exchange() {
+        return new TopicExchange(PUB_SUB_TOPIC);
+    }
+
+    @Bean
+    public Binding emailBinding(Queue emailQueue, TopicExchange exchange) {
+        return BindingBuilder.bind(emailQueue).to(exchange).with("notification");
+    }
+
+    @Bean
+    public Binding textBinding(Queue textQueue, TopicExchange exchange) {
+        return BindingBuilder.bind(textQueue).to(exchange).with("notification");
+    }
+
+    @Bean
+    public Publisher publisher(RabbitTemplate rabbitTemplate) {
+        return new Publisher(rabbitTemplate, MESSAGE_QUEUE, PUB_SUB_TOPIC);
+    }
+
+    public static void main(String[] args) {
+        SpringApplication.run(ServerApplication.class, args);
+    }
+}