Kafkastream - spring cloud stream - custom tolopogy without bindings in configuration file - apache-kafka-streams

This projects don't describe classic bindings in application config file, we override the StreamsBuilderFactoryBean definition like this to be able to generate the topology manually.
#Bean
public StreamsBuilderFactoryBean createSBFB(){
StreamsBuilderFactoryBean streamsBuilderFactoryBean = new StreamsBuilderFactoryBean(streamConfiguration);
streamsBuilderFactoryBean.setInfrastructureCustomizer(
new KafkaStreamsInfrastructureCustomizer() {
#Override
public void configureBuilder(StreamsBuilder builder) {
builder.stream(...) // here we append our topology
}
}
}
This is perfectly working but we are loosing healthcheck mecanism, and kafkastream actuator metrics.
Is there a way to work around ?
the main goal is to retrieve the topology from a rest service. Can we use spring cloud stream in this context ?

Related

Spring 6: Spring Cloud Stream Kafka - Replacement for #EnableBinding

I was reading "Spring Microservices In Action (2021)" because I wanted to brush up on Microservices.
Now with Spring Boot 3 a few things changed. In the book, an easy example of how to push messages to a topic and how to consume messages to a topic were presented.
The Problem is: The examples presented do just not work with Spring Boot 3. Sending Messages from a Spring Boot 2 Project works. The underlying project can be found here:
https://github.com/ihuaylupo/manning-smia/tree/master/chapter10
Example 1 (organization-service):
Consider this Config:
spring.cloud.stream.bindings.output.destination=orgChangeTopic
spring.cloud.stream.bindings.output.content-type=application/json
spring.cloud.stream.kafka.binder.zkNodes=kafka #kafka is used as a network alias in docker-compose
spring.cloud.stream.kafka.binder.brokers=kafka
And this Component(Class) which can is injected in a service in this project
#Component
public class SimpleSourceBean {
private Source source;
private static final Logger logger = LoggerFactory.getLogger(SimpleSourceBean.class);
#Autowired
public SimpleSourceBean(Source source){
this.source = source;
}
public void publishOrganizationChange(String action, String organizationId){
logger.debug("Sending Kafka message {} for Organization Id: {}", action, organizationId);
OrganizationChangeModel change = new OrganizationChangeModel(
OrganizationChangeModel.class.getTypeName(),
action,
organizationId,
UserContext.getCorrelationId());
source.output().send(MessageBuilder.withPayload(change).build());
}
}
This code fires a message to the topic (destination) orgChangeTopic. The way I understand it, the firsttime a message is fired, the topic is created.
Question 1: How do I do this Spring Boot 3? Config-Wise and "Code-Wise"?
Example 2:
Consider this config:
spring.cloud.stream.bindings.input.destination=orgChangeTopic
spring.cloud.stream.bindings.input.content-type=application/json
spring.cloud.stream.bindings.input.group=licensingGroup
spring.cloud.stream.kafka.binder.zkNodes=kafka
spring.cloud.stream.kafka.binder.brokers=kafka
And this code:
#SpringBootApplication
#RefreshScope
#EnableDiscoveryClient
#EnableFeignClients
#EnableEurekaClient
#EnableBinding(Sink.class)
public class LicenseServiceApplication {
public static void main(String[] args) {
SpringApplication.run(LicenseServiceApplication.class, args);
}
#StreamListener(Sink.INPUT)
public void loggerSink(OrganizationChangeModel orgChange) {
log.info("Received an {} event for organization id {}",
orgChange.getAction(), orgChange.getOrganizationId());
}
What this method is supposed to do is to fire whenever a message is fired in orgChangeTopic, we want the method loggerSink to fire.
How do I do this in Spring Boot 3?
In Spring Cloud Stream 4.0.0 (the version used if you are using Boot 3), a few things are removed - such as the EnableBinding, StreamListener, etc. We deprecated them before in 3.x and finally removed them in the 4.0.0 version. The annotation-based programming model is removed in favor of the functional programming style enabled through the Spring Cloud Function project. You essentially express your business logic as java.util.function.Funciton|Consumer|Supplier etc. for a processor, sink, and source, respectively. For ad-hoc source situations, as in your first example, Spring Cloud Stream provides a StreamBridge API for custom sends.
Your example #1 can be re-written like this:
#Component
public class SimpleSourceBean {
#Autowired
StreamBridge streamBridge
public void publishOrganizationChange(String action, String organizationId){
logger.debug("Sending Kafka message {} for Organization Id: {}", action, organizationId);
OrganizationChangeModel change = new OrganizationChangeModel(
OrganizationChangeModel.class.getTypeName(),
action,
organizationId,
UserContext.getCorrelationId());
streamBridge.send("output-out-0", MessageBuilder.withPayload(change).build());
}
}
Config
spring.cloud.stream.bindings.output-out-0.destination=orgChangeTopic
spring.cloud.stream.kafka.binder.brokers=kafka
Just so you know, you no longer need that zkNode property. Neither the content type since the framework auto-converts that for you.
StreamBridge send takes a binding name and the payload. The binding name can be anything - but for consistency reasons, we used output-out-0 here. Please read the reference docs for more context around the reasoning for this binding name.
If you have a simple source that runs on a timer, you can express this simply as a supplier as below (instead of using a StreamBrdige).
#Bean
public Supplier<OrganizationChangeModel> ouput() {
return () -> {
// return the payload
};
}
spring.cloud.function.definition=output
spring.cloud.bindings.output-out-0.destination=...
Example #2
#Bean
public Consumer<OrganizationChangeModel> loggerSink() {
return model -> {
log.info("Received an {} event for organization id {}",
orgChange.getAction(), orgChange.getOrganizationId());
};
}
Config:
spring.cloud.function.definition=loggerSink
spring.cloud.stream.bindings.loggerSink-in-0.destination=orgChangeTopic
spring.cloud.stream.bindings.loggerSinnk-in-0.group=licensingGroup
spring.cloud.stream.kafka.binder.brokers=kafka
If you want the input/output binding names to be specifically input or output rather than with in-0, out-0 etc., there are ways to make that happen. Details for this are in the reference docs.

Reload consumer properties with spring kafka

We have developed live reloading of config properties with spring boot applications. I have a spring-kafka consumer and I wanted to leverage the live reloading where if I change the consumer property I should be able to start the container without rebooting the application. I used:
KafkaListenerEndpointRegistry.stop()
KafkaListenerEndpointRegistry.start()
I thought the above actually creates a new container but that is not the case. So I wanted to find out if I have to start a container with new config properties how do I do that
#Bean
#ConfigurationProperties(prefix = "container.config.properties")
#ConditionalOnMissingBean
#RefreshScope
ContainerConfigProperties containerConfigProperties() {
return new ContainerConfigProperties();
}
#Bean
#ConditionalOnMissingBean
#ConditionalOnBean(value = {ContainerConfigProperties.class})
#RefreshScope
<K, V> ConcurrentKafkaListenerContainerFactory<K, ValueDeserializerContainer<V>> kafkaListenerContainerFactory(final ConsumerFactory<K, ValueDeserializerContainer<V>> consumerFactory,
final ContainerConfigProperties containerConfigProperties,
final Optional<IAMIdentity> iamIdentity) {
val factory = new ConcurrentKafkaListenerContainerFactory<K, ValueDeserializerContainer<V>>();
factory.setBatchListener(true);
factory.setBatchErrorHandler(new SeekToCurrentBatchErrorHandler());
factory.setConsumerFactory(consumerFactory);
factory.getContainerProperties().setAckMode(containerConfigProperties.getAckMode());
factory.setConcurrency(containerConfigProperties.getConcurrency());
factory.getContainerProperties().setConsumerRebalanceListener(simpleConsumerRebalanceListener());
// update kafka consumer properties. Default is taken from the config file
iamIdentity.ifPresent(identity -> consumerFactory.updateConfigs(addIAMIdentity(identity)));
log.info("kafkaListenerContainerFactory");
return factory;
}
Exactly which properties are you changing? The child containers are indeed recreated when stopping/starting the parent container so any ContainerProperties changes will be picked up.
If you are talking about kafka consumer properties, you either need to reconfigure the consumer factory, or set the changed properties via the ContainerProperties.kafkaConsumerProperties to override the consumer factory settings.
EDIT
Something like this might work:
#Bean
#RefreshScope
Object containerReconfigurer(KafkaListenerEndpointRegistry registry) {
registry.getListenerContainers().forEach(container -> {
container.stop();
// reconfigure container
container.start();
});
return null;
}

Issues migrating a Spring AMQP consumer/producer service to a Spring Stream source

I am migrating a Spring Boot microservice that consumes data from 3 RabbitMQ queues on server A, saves it into Redis and finally produces messages into an exchange in a different RabbitMQ on server B so these messages can be consumed by another microservice. This flow is working fine but I would like to migrate it to Spring Cloud Stream using the RabbitMQ binder. All Spring AMQP configuration is customised in the properties file and no spring property is used to create connections, queues, bindings, etc...
My first idea was setting up two bindings in Spring Cloud Stream, one connected to server A (consumer) and the other connected to server B (producer), and migrate the existing code to a Processor but I discarded it because it seems connection names cannot be set yet if multiple binders are used and I need to add several bindings to consume from server A's queues and bindingRoutingKey property does not support a list of values (I know it can be done programmately as explained here).
So I decided to only refactor the part of code related to the producer to use Spring Cloud Stream over RabbitMQ so the same microservice should consume via Spring AMQP from server A (original code) and should produce into server B via Spring Cloud Stream.
The first issue I found was a NonUniqueBeanDefinitionException in Spring Cloud Stream because a org.springframework.messaging.handler.annotation.support.MessageHandlerMethodFactory bean was defined twice with handlerMethodFactory and integrationMessageHandlerMethodFactory names.
org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'org.springframework.messaging.handler.annotation.support.MessageHandlerMethodFactory' available: expected single matching bean but found 2: handlerMethodFactory,integrationMessageHandlerMethodFactory
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveNamedBean(DefaultListableBeanFactory.java:1144)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveBean(DefaultListableBeanFactory.java:411)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:344)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBean(DefaultListableBeanFactory.java:337)
at org.springframework.context.support.AbstractApplicationContext.getBean(AbstractApplicationContext.java:1123)
at org.springframework.cloud.stream.binding.StreamListenerAnnotationBeanPostProcessor.injectAndPostProcessDependencies(StreamListenerAnnotationBeanPostProcessor.java:317)
at org.springframework.cloud.stream.binding.StreamListenerAnnotationBeanPostProcessor.afterSingletonsInstantiated(StreamListenerAnnotationBeanPostProcessor.java:113)
at org.springframework.beans.factory.support.DefaultListableBeanFactory.preInstantiateSingletons(DefaultListableBeanFactory.java:862)
at org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization(AbstractApplicationContext.java:877)
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:549)
at org.springframework.boot.web.servlet.context.ServletWebServerApplicationContext.refresh(ServletWebServerApplicationContext.java:141)
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:743)
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:390)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:312)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1214)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1203)
It seems the former bean is created by Spring AMQP and the latter by Spring Cloud Stream so I created my own primary bean:
#Bean
#Primary
public MessageHandlerMethodFactory messageHandlerMethodFactory() {
return new DefaultMessageHandlerMethodFactory();
}
Now the application is able to start but the output channel is created by Spring Cloud Stream in server A instead of server B. It seems that Spring Cloud Stream configuration is using the connection created by Spring AMQP instead of using its own configuration.
The configuration of Spring AMQP is this:
#Bean
public SimpleRabbitListenerContainerFactory priceRabbitListenerContainerFactory(
ConnectionFactory consumerConnectionFactory) {
return
getSimpleRabbitListenerContainerFactory(
consumerConnectionFactory,
rabbitProperties.getConsumer().getListeners().get(LISTENER_A));
}
#Bean
public SimpleRabbitListenerContainerFactory maxbetRabbitListenerContainerFactory(
ConnectionFactory consumerConnectionFactory) {
return
getSimpleRabbitListenerContainerFactory(
consumerConnectionFactory,
rabbitProperties.getConsumer().getListeners().get(LISTENER_B));
}
#Bean
public ConnectionFactory consumerConnectionFactory() throws Exception {
return
new CachingConnectionFactory(
getRabbitConnectionFactoryBean(
rabbitProperties.getConsumer()
).getObject()
);
}
private SimpleRabbitListenerContainerFactory getSimpleRabbitListenerContainerFactory(
ConnectionFactory connectionFactory,
RabbitProperties.ListenerProperties listenerProperties) {
//return a SimpleRabbitListenerContainerFactory set up from external properties
}
/**
* Create the AMQ Admin.
*/
#Bean
public AmqpAdmin consumerAmqpAdmin(ConnectionFactory consumerConnectionFactory) {
return new RabbitAdmin(consumerConnectionFactory);
}
/**
* Create the map of available queues and declare them in the admin.
*/
#Bean
public Map<String, Queue> queues(AmqpAdmin consumerAmqpAdmin) {
return
rabbitProperties.getConsumer().getListeners().entrySet().stream()
.map(listenerEntry -> {
Queue queue =
QueueBuilder
.nonDurable(listenerEntry.getValue().getQueueName())
.autoDelete()
.build();
consumerAmqpAdmin.declareQueue(queue);
return new AbstractMap.SimpleEntry<>(listenerEntry.getKey(), queue);
}).collect(
Collectors.toMap(
AbstractMap.SimpleEntry::getKey,
AbstractMap.SimpleEntry::getValue
)
);
}
/**
* Create the map of available exchanges and declare them in the admin.
*/
#Bean
public Map<String, TopicExchange> exchanges(AmqpAdmin consumerAmqpAdmin) {
return
rabbitProperties.getConsumer().getListeners().entrySet().stream()
.map(listenerEntry -> {
TopicExchange exchange =
new TopicExchange(listenerEntry.getValue().getExchangeName());
consumerAmqpAdmin.declareExchange(exchange);
return new AbstractMap.SimpleEntry<>(listenerEntry.getKey(), exchange);
}).collect(
Collectors.toMap(
AbstractMap.SimpleEntry::getKey,
AbstractMap.SimpleEntry::getValue
)
);
}
/**
* Create the list of bindings and declare them in the admin.
*/
#Bean
public List<Binding> bindings(Map<String, Queue> queues, Map<String, TopicExchange> exchanges, AmqpAdmin consumerAmqpAdmin) {
return
rabbitProperties.getConsumer().getListeners().keySet().stream()
.map(listenerName -> {
Queue queue = queues.get(listenerName);
TopicExchange exchange = exchanges.get(listenerName);
return
rabbitProperties.getConsumer().getListeners().get(listenerName).getKeys().stream()
.map(bindingKey -> {
Binding binding = BindingBuilder.bind(queue).to(exchange).with(bindingKey);
consumerAmqpAdmin.declareBinding(binding);
return binding;
}).collect(Collectors.toList());
}).flatMap(Collection::stream)
.collect(Collectors.toList());
}
Message listeners are:
#RabbitListener(
queues="${consumer.listeners.LISTENER_A.queue-name}",
containerFactory = "priceRabbitListenerContainerFactory"
)
public void handleMessage(Message rawMessage, org.springframework.messaging.Message<ModelPayload> message) {
// call a service to process the message payload
}
#RabbitListener(
queues="${consumer.listeners.LISTENER_B.queue-name}",
containerFactory = "maxbetRabbitListenerContainerFactory"
)
public void handleMessage(Message rawMessage, org.springframework.messaging.Message<ModelPayload> message) {
// call a service to process the message payload
}
Properties:
#
# Server A config (Spring AMQP)
#
consumer.host=server-a
consumer.username=
consumer.password=
consumer.port=5671
consumer.ssl.enabled=true
consumer.ssl.algorithm=TLSv1.2
consumer.ssl.validate-server-certificate=false
consumer.connection-name=local:microservice-1
consumer.thread-factory.thread-group-name=server-a-consumer
consumer.thread-factory.thread-name-prefix=server-a-consumer-
# LISTENER_A configuration
consumer.listeners.LISTENER_A.queue-name=local.listenerA
consumer.listeners.LISTENER_A.exchange-name=exchangeA
consumer.listeners.LISTENER_A.keys[0]=*.1.*.*
consumer.listeners.LISTENER_A.keys[1]=*.3.*.*
consumer.listeners.LISTENER_A.keys[2]=*.6.*.*
consumer.listeners.LISTENER_A.keys[3]=*.8.*.*
consumer.listeners.LISTENER_A.keys[4]=*.9.*.*
consumer.listeners.LISTENER_A.initial-concurrency=5
consumer.listeners.LISTENER_A.maximum-concurrency=20
consumer.listeners.LISTENER_A.thread-name-prefix=listenerA-consumer-
# LISTENER_B configuration
consumer.listeners.LISTENER_B.queue-name=local.listenerB
consumer.listeners.LISTENER_B.exchange-name=exchangeB
consumer.listeners.LISTENER_B.keys[0]=*.1.*
consumer.listeners.LISTENER_B.keys[1]=*.3.*
consumer.listeners.LISTENER_B.keys[2]=*.6.*
consumer.listeners.LISTENER_B.initial-concurrency=5
consumer.listeners.LISTENER_B.maximum-concurrency=20
consumer.listeners.LISTENER_B.thread-name-prefix=listenerB-consumer-
#
# Server B config (Spring Cloud Stream)
#
spring.rabbitmq.host=server-b
spring.rabbitmq.port=5672
spring.rabbitmq.username=
spring.rabbitmq.password=
spring.cloud.stream.bindings.outbound.destination=microservice-out
spring.cloud.stream.bindings.outbound.group=default
spring.cloud.stream.rabbit.binder.connection-name-prefix=local:microservice
So my question is: is it possible to use in the same Spring Boot application code that consumes data from RabbitMQ via Spring AMQP and produces messages into a different server via Spring Cloud Stream RabbitMQ? If it is, could somebody tell me what I am doing wrong, please?
Spring AMQP version is the one provided by Boot version 2.1.7 (2.1.8-RELEASE) and Spring Cloud Stream version is the one provided by Spring Cloud train Greenwich.SR2 (2.1.3.RELEASE).
EDIT
I was able to make it work configuring the binder via multiple configuration properties instead of the default one. So with this configuration it works:
#
# Server B config (Spring Cloud Stream)
#
spring.cloud.stream.binders.transport-layer.type=rabbit
spring.cloud.stream.binders.transport-layer.environment.spring.rabbitmq.host=server-b
spring.cloud.stream.binders.transport-layer.environment.spring.rabbitmq.port=5672
spring.cloud.stream.binders.transport-layer.environment.spring.rabbitmq.username=
spring.cloud.stream.binders.transport-layer.environment.spring.rabbitmq.password=
spring.cloud.stream.bindings.stream-output.destination=microservice-out
spring.cloud.stream.bindings.stream-output.group=default
Unfortunately it is not possible to set the connection-name yet in multiple binders configuration: A custom ConnectionNameStrategy is ignored if there is a custom binder configuration.
Anyway, I still do not understand why it seems the contexts are "mixed" when using Spring AMQP and Spring Cloud Stream RabbitMQ. It is still necessary to set a primary MessageHandlerMethodFactory bean in order the implementation to work.
EDIT
I found out that the NoUniqueBeanDefinitionException was caused because the microservice itself was creating a ConditionalGenericConverter to be used by Spring AMQP part to deserialize messages from Server A.
I removed it and added some MessageConverters instead. Now the problem is solved and the #Primary bean is no longer necessary.
Unrelated, but
consumerAmqpAdmin.declareQueue(queue);
You should never communicate with the broker within a #Bean definition; it is too early in application context lifecycle. It might work but YMMV; also if the broker is not available it will prevent your app from starting.
It's better to define beans of type Declarables containing the lists of queues, channels, bindings and the Admin will automatically declare them when the connection is first opened successfully. See the reference manual.
I have never seen the MessageHandlerFactory problem; Spring AMQP declares no such bean. If you can provide a small sample app that exhibits the behavior, that would be useful.
I'll see if I can find a work around to the connection name issue.
EDIT
I found a work around to the connection name issue; it involves a bit of reflection but it works. I suggest you open a new feature request against the binder to request a mechanism to set the connection name strategy when using multiple binders.
Anyway; here's the work around...
#SpringBootApplication
#EnableBinding(Processor.class)
public class So57725710Application {
public static void main(String[] args) {
SpringApplication.run(So57725710Application.class, args);
}
#Bean
public Object connectionNameConfigurer(BinderFactory binderFactory) throws Exception {
setConnectionName(binderFactory, "rabbit1", "myAppProducerSide");
setConnectionName(binderFactory, "rabbit2", "myAppConsumerSide");
return null;
}
private void setConnectionName(BinderFactory binderFactory, String binderName,
String conName) throws Exception {
binderFactory.getBinder(binderName, MessageChannel.class); // force creation
#SuppressWarnings("unchecked")
Map<String, Map.Entry<Binder<?, ?, ?>, ApplicationContext>> binders =
(Map<String, Entry<Binder<?, ?, ?>, ApplicationContext>>) new DirectFieldAccessor(binderFactory)
.getPropertyValue("binderInstanceCache");
binders.get(binderName)
.getValue()
.getBean(CachingConnectionFactory.class).setConnectionNameStrategy(queue -> conName);
}
#StreamListener(Processor.INPUT)
#SendTo(Processor.OUTPUT)
public String listen(String in) {
System.out.println(in);
return in.toUpperCase();
}
}
and
spring.cloud.stream.binders.rabbit1.type=rabbit
spring.cloud.stream.binders.rabbit1.environment.spring.rabbitmq.host=localhost
spring.cloud.stream.binders.rabbit1.environment.spring.rabbitmq.port=5672
spring.cloud.stream.binders.rabbit1.environment.spring.rabbitmq.username=guest
spring.cloud.stream.binders.rabbit1.environment.spring.rabbitmq.password=guest
spring.cloud.stream.bindings.output.destination=outDest
spring.cloud.stream.bindings.output.producer.required-groups=outQueue
spring.cloud.stream.bindings.output.binder=rabbit1
spring.cloud.stream.binders.rabbit2.type=rabbit
spring.cloud.stream.binders.rabbit2.environment.spring.rabbitmq.host=localhost
spring.cloud.stream.binders.rabbit2.environment.spring.rabbitmq.port=5672
spring.cloud.stream.binders.rabbit2.environment.spring.rabbitmq.username=guest
spring.cloud.stream.binders.rabbit2.environment.spring.rabbitmq.password=guest
spring.cloud.stream.bindings.input.destination=inDest
spring.cloud.stream.bindings.input.group=default
spring.cloud.stream.bindings.input.binder=rabbit2
and

Send and receive files from FTP in Spring Boot

I'm new to Spring Framework and, indeed, I'm learning and using Spring Boot. Recently, in the app I'm developing, I made Quartz Scheduler work, and now I want to make Spring Integration work there: FTP connection to a server to write and read files from.
What I want is really simple (as I've been able to do so in a previous java application). I've got two Quartz Jobs scheduled to fired in different times daily: one of them reads a file from a FTP server and another one writes a file to a FTP server.
I'll detail what I've developed so far.
#SpringBootApplication
#ImportResource("classpath:ws-config.xml")
#EnableIntegration
#EnableScheduling
public class MyApp extends SpringBootServletInitializer {
#Autowired
private Configuration configuration;
//...
#Bean
public DefaultFtpsSessionFactory myFtpsSessionFactory(){
DefaultFtpsSessionFactory sess = new DefaultFtpsSessionFactory();
Ftp ftp = configuration.getFtp();
sess.setHost(ftp.getServer());
sess.setPort(ftp.getPort());
sess.setUsername(ftp.getUsername());
sess.setPassword(ftp.getPassword());
return sess;
}
}
The following class I've named it as a FtpGateway, as follows:
#Component
public class FtpGateway {
#Autowired
private DefaultFtpsSessionFactory sess;
public void sendFile(){
// todo
}
public void readFile(){
// todo
}
}
I'm reading this documentation to learn to do so. Spring Integration's FTP seems to be event driven, so I don't know how can I execute either of the sendFile() and readFile() from by Jobs when the trigger is fired at an exact time.
The documentation tells me something about using Inbound Channel Adapter (to read files from a FTP?), Outbound Channel Adapter (to write files to a FTP?) and Outbound Gateway (to do what?):
Spring Integration supports sending and receiving files over FTP/FTPS by providing three client side endpoints: Inbound Channel Adapter, Outbound Channel Adapter, and Outbound Gateway. It also provides convenient namespace-based configuration options for defining these client components.
So, I haven't got it clear as how to follow.
Please, could anybody give me a hint?
Thank you!
EDIT:
Thank you #M. Deinum. First, I'll try a simple task: read a file from the FTP, the poller will run every 5 seconds. This is what I've added:
#Bean
public FtpInboundFileSynchronizer ftpInboundFileSynchronizer() {
FtpInboundFileSynchronizer fileSynchronizer = new FtpInboundFileSynchronizer(myFtpsSessionFactory());
fileSynchronizer.setDeleteRemoteFiles(false);
fileSynchronizer.setPreserveTimestamp(true);
fileSynchronizer.setRemoteDirectory("/Entrada");
fileSynchronizer.setFilter(new FtpSimplePatternFileListFilter("*.csv"));
return fileSynchronizer;
}
#Bean
#InboundChannelAdapter(channel = "ftpChannel", poller = #Poller(fixedDelay = "5000"))
public MessageSource<File> ftpMessageSource() {
FtpInboundFileSynchronizingMessageSource source = new FtpInboundFileSynchronizingMessageSource(inbound);
source.setLocalDirectory(new File(configuracion.getDirFicherosDescargados()));
source.setAutoCreateLocalDirectory(true);
source.setLocalFilter(new AcceptOnceFileListFilter<File>());
return source;
}
#Bean
#ServiceActivator(inputChannel = "ftpChannel")
public MessageHandler handler() {
return new MessageHandler() {
#Override
public void handleMessage(Message<?> message) throws MessagingException {
Object payload = message.getPayload();
if(payload instanceof File){
File f = (File) payload;
System.out.println(f.getName());
}else{
System.out.println(message.getPayload());
}
}
};
}
Then, when the app is running, I put a new csv file intro "Entrada" remote folder, but the handler() method isn't run after 5 seconds... I'm doing something wrong?
Please add #Scheduled(fixedDelay = 5000) over your poller method.
You should use SPRING BATCH with tasklet. It is far easier to configure bean, crone time, input source with existing interfaces provided by Spring.
https://www.baeldung.com/introduction-to-spring-batch
Above example is annotation and xml based both, you can use either.
Other benefit Take use of listeners and parallel steps. This framework can be used in Reader - Processor - Writer manner as well.

Camel: use datasource configured by spring-boot

I have a project and in it I'm using spring-boot-jdbc-starter and it automatically configures a DataSource for me.
Now I added camel-spring-boot to project and I was able to successfully create routes from Beans of type RouteBuilder.
But when I'm using sql component of camel it can not find datasource. Is there any simple way to add Spring configured datasource to CamelContext? In samples of camel project they use spring xml for datasource configuration but I'm looking for a way with java config. This is what I tried:
#Configuration
public class SqlRouteBuilder extends RouteBuilder {
#Bean
public SqlComponent sqlComponent(DataSource dataSource) {
SqlComponent sqlComponent = new SqlComponent();
sqlComponent.setDataSource(dataSource);
return sqlComponent;
}
#Override
public void configure() throws Exception {
from("sql:SELECT * FROM tasks WHERE STATUS NOT LIKE 'completed'")
.to("mock:sql");
}
}
I have to publish it because although the answer is in the commentary, you may not notice it, and in my case such a configuration was necessary to run the process.
The use of the SQL component should look like this:
from("timer://dbQueryTimer?period=10s")
.routeId("DATABASE_QUERY_TIMER_ROUTE")
.to("sql:SELECT * FROM event_queue?dataSource=#dataSource")
.process(xchg -> {
List<Map<String, Object>> row = xchg.getIn().getBody(List.class);
row.stream()
.map((x) -> {
EventQueue eventQueue = new EventQueue();
eventQueue.setId((Long)x.get("id"));
eventQueue.setData((String)x.get("data"));
return eventQueue;
}).collect(Collectors.toList());
})
.log(LoggingLevel.INFO,"******Database query executed - body:${body}******");
Note the use of ?dataSource=#dataSource. The dataSource name points to the DataSource object configured by Spring, it can be changed to another one and thus use different DataSource in different routes.
Here is the sample/example code (Java DSL). For this I used
Spring boot
H2 embedded Database
Camel
on startup spring-boot, creates table and loads data. Then camel route, runs "select" to pull the data.
Here is the code:
public void configure() throws Exception {
from("timer://timer1?period=1000")
.setBody(constant("select * from Employee"))
.to("jdbc:dataSource")
.split().simple("${body}")
.log("process row ${body}")
full example in github

Resources