ndemengel

@PostConstruct
public void createExchangesAndQueuesAndBindings() {
    // only one line left for each exchange/queues association!
    createAndBindQueuesToFanoutExchangeAndDeadLetter(EMAIL_UPDATED_EXCHANGE, MAILCHIMP_EMAIL_UPDATED_QUEUE);
    // ... other associations...
}

private void createAndBindQueuesToFanoutExchangeAndDeadLetter(String exchangeName, String... queueNames) {
    FanoutExchange exchangeBean = createExchangeBean(exchangeName);

ndemengel

// let's use our own annotation!
@RabbitEventListener(queue = "email.updated.mailchimp.queue", exchange = RabbitConfig.EMAIL_UPDATED_EXCHANGE)
public void emailUpdated(EmailUpdated event) {
    updateMailChimpMember(event.getOldEmail(), event.getNewEmail());
}

ndemengel

// the exchange is not mentioned anymore here
@RabbitEventListener(queue = "email.updated.mailchimp.queue")
public void emailUpdated(EmailUpdated event) {
    updateMailChimpMember(event.getOldEmail(), event.getNewEmail());
}

ndemengel

import lombok.Value;

// This code only works if compiling the code using javac's -parameters option (Java 8 only).
// With this option, Jackons can use the all-args constructor of our type.
// See https://gist.github.com/ndemengel/72f362bc31afe5fcaa0499af8f269651 for a more general solution.
@Value
public class EmailUpdated implements Event {

    public static final String EXCHANGE_NAME = "email.updated.exchange";

ndemengel

@Value
public class EmailUpdated implements Event {

    public static final String EXCHANGE_NAME = "email.updated.exchange";

    String accountId;
    String oldEmail;
    String newEmail;
}

ndemengel

import org.junit.runner.RunWith;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(classes = {
    // only populate the context with the classes that interest us for this test
    SomePublisher.class,
    JvmSynchronizedEventsService.class,
    SomeConsumer.class

ndemengel

import com.thoughtworks.qdox.JavaProjectBuilder;
import com.thoughtworks.qdox.model.*;
import org.junit.Test;

import java.io.*;
import java.text.MessageFormat;
import java.util.*;

import static java.util.Arrays.asList;
import static java.util.Arrays.stream;

ndemengel

@Component
class PushTransactionForInvoice(
        private val transactionPushService: TransactionPushService
) : Command(PushTransactionForInvoiceSpec::class) {

    override fun execute(arguments: Map<String, Any?>): CommandExecutionResult {
        val invoiceId = InvoiceId(arguments["invoiceId"] as String)
        val transactionId = TransactionId(arguments["transactionId"] as String)

        transactionPushService.pushTransactionForInvoice(transactionId, invoiceId)

ndemengel

@Component
class ClientCode(
        @Named(MY_QUEUE_NAME)
        private val commandScheduler: CommandScheduler
) {
    fun doSomething() {
        // ... some code ...
        val transactionId: TransactionId = ...
        val invoiceId: InvoiceId = ...
        commandScheduler.schedule(PushTransactionForInvoiceSpec(transactionId, invoiceId))

ndemengel

const val MY_QUEUE_NAME: String = "myServiceQueue"

@Configuration
class MyServiceQueueConfiguration {

    @Bean(MY_QUEUE_NAME)
    fun myServiceQueue(commandExecutionQueueFactory: CommandExecutionQueueFactory) =
        commandExecutionQueueFactory.createQueue(
                MY_QUEUE_NAME,