Axon 4 configuration

// Axon dependencies in pom.xml

    <dependency>
			<groupId>org.axonframework</groupId>
			<artifactId>axon-eventsourcing</artifactId>
			<version>${axon.version}</version>
		</dependency>
		<dependency>
			<groupId>org.axonframework</groupId>
			<artifactId>axon-modelling</artifactId>
			<version>${axon.version}</version>
		</dependency>
		<dependency>
			<groupId>org.axonframework</groupId>
			<artifactId>axon-messaging</artifactId>
			<version>${axon.version}</version>
		</dependency>
		<dependency>
			<groupId>org.axonframework</groupId>
			<artifactId>axon-configuration</artifactId>
			<version>${axon.version}</version>
		</dependency>
		<dependency>
			<groupId>org.axonframework</groupId>
			<artifactId>axon-spring</artifactId>
			<version>${axon.version}</version>
		</dependency>
		<dependency>
			<groupId>org.axonframework</groupId>
			<artifactId>axon-test</artifactId>
			<version>${axon.version}</version>
		</dependency>


// context configuration
@Configuration
public class AppConfiguration {

    @Bean
    public DataSource dataSource() {
        return DataSourceBuilder
                .create()
                .username("sa")
                .password("")
                .url("jdbc:h2:mem:exploredb")
                .driverClassName("org.h2.Driver")
                .build();
    }

    @Bean
    EventProcessingModule eventProcessingModule() {
        return new EventProcessingModule();
    }

    @Bean
    EventStore embeddedEventStore() throws SQLException {
        return EmbeddedEventStore.builder()
                .storageEngine(new InMemoryEventStorageEngine())
                .build();
    }

    @Bean
    public SimpleCommandBus commandBus() {
        return SimpleCommandBus.builder().build();
    }


    @Bean
    public DefaultCommandGateway commandGateway() {
        return DefaultCommandGateway.builder()
                .commandBus(commandBus())
                .build();
    }
    
    @Bean
    public Repository<Account> eventSourcingRepository() throws SQLException {
        return EventSourcingRepository.builder(Account.class)
                .eventStore(embeddedEventStore())
                .build();
    }

    @Bean
    public AggregateAnnotationCommandHandler aggregateAnnotationCommandHandler() throws SQLException {

        AggregateAnnotationCommandHandler<Account> handler = AggregateAnnotationCommandHandler.<Account>builder()
                .aggregateType(Account.class)
                .repository(eventSourcingRepository())
                .build();

        for (String supportedCommand : handler.supportedCommandNames()) {
            commandBus().subscribe(supportedCommand, handler);
        }
        return handler;
    }
    
// main class
@SpringBootApplication
public class ExploringAxonApplication {

    @Autowired
    public void configure(EventProcessingConfigurer configurer) {
        // some Event Handlers are annotated with @ProcessingGroup("normalProcessor")
        configurer.registerTrackingEventProcessor("normalProcessor");
    }


    public static void main(String[] args) {
        SpringApplication.run(ExploringAxonApplication.class, args);
    }
}