How to "translate" the following XML configuration to the equivalent Spring integration java-dsl?
<int:publish-subscribe-channel id="channel" task-executor="myex">
</int:publish-subscribe-channel>
<task:executor id="myex" pool-size="10"></task:executor>
I've read the DSL Reference Guide, but still can't figure it out.
MessageChannels chapter points out to the MessageChannels factory. So, <publish-subscribe-channel> XML config translates to Java config like:
#Bean
public MessageChannel channel() {
return MessageChannels.publishSubscribe(myExecutor()).get();
}
Although you can reach the same just with raw Java config:
#Bean
public MessageChannel channel() {
return new PublishSubscribeChannel(myExecutor());
}
Related
I have successfully integrated kafka outbound channle adapter with fixed topic name. Now, i want to make the topic name configurable and hence, want to expose it via application properties.
application.properties contain one of the following entry:
kafkaTopic:testNewTopic
My configuration class looks like below:
#Configuration
#Component
public class KafkaConfig {
#Value("${kafkaTopic}")
private String kafkaTopicName;
#Bean
public String getTopic(){
return kafkaTopicName;
}
#Bean
public KafkaTemplate<String, String> kafkaTemplate() {
return new KafkaTemplate<>(producerFactory());
}
#Bean
public ProducerFactory<String, String> producerFactory() {
Map<String, Object> props = new HashMap<>();
props.put(ProducerConfig.BOOTSTRAP_SERVERS_CONFIG, "localhost:9092");//this.brokerAddress);
props.put(ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer");
props.put(ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringSerializer");
// set more properties
return new DefaultKafkaProducerFactory<>(props);
}
}
and in my si-config.xml, i have used the following (ex: topic="getTopic") :
<int-kafka:outbound-channel-adapter
id="kafkaOutboundChannelAdapter" kafka-template="kafkaTemplate"
auto-startup="true" sync="true" channel="inputToKafka" topic="getTopic">
</int-kafka:outbound-channel-adapter>
However, the configuration is unable to pick up the topic name when exposed via bean. But it works fine when i hard code the value of the topic name.
Can someone please suggest what i am doing wrong here?
Does topic within kafka outbound channel accept the value referred as bean?
How do i externalize it as every application using my utility will supply different kafka topic names
The topic attribute is for string value.
However it supports property placeholder resolution:
topic="${kafkaTopic}"
and also SpEL evaluation for aforementioned bean:
topic="#{getTopic}"
Just because this is allowed by the XML parser configuration.
However you may pay attention that KafkaTemplate, which you inject into the <int-kafka:outbound-channel-adapter> has defaultTopic property. Therefore you won't need to worry about that XML.
And one more option available for you is Spring Integration Annotations configuration. Where you can define a #ServiceActivator for the KafkaProducerMessageHandler #Bean:
#ServiceActivator(inputChannel = "inputToKafka")
#Bean
KafkaProducerMessageHandler kafkaOutboundChannelAdapter() {
kafkaOutboundChannelAdapter adapter = new kafkaOutboundChannelAdapter( kafkaTemplate());
adapter.setSync(true);
adapter.setTopicExpression(new LiteralExpression(this.kafkaTopicName));
return adapter;
}
I got a JmsConfig configuration class that handles JMS events from a topic in the following way:
It defines a #Bean ConnectionFactory, containing an ActiveMQ implementation
It defines a #Bean JmsListenerContainerFactory instantiating a DefaultJmsListenerContainerFactory and passing it through Boot's DefaultJmsListenerContainerFactoryConfigurer
It defines a #Bean MessageConverter containing a MappingJackson2MessageConverter and setting a custom ObjectMapper
I use #JmsListener annotation pointing to myfactory on a method of my service. This is the only use I have for the topic, subscription alone.
Now I want to move to Spring Integration. After reading a lot, and provided I don't need a bidirectional use (discarding Gateways) neither a polling mechanism (discarding #InboundChannelAdapter), I am going for a message-driven-channel-adapter, in traditional XML configuration wording. I found that Java idiom should be accomplished by means of the new Spring Integration DSL library, and thus, I look for the proper snippet.
It seems JmsMessageDrivenChannelAdapter is the proper equivalent, and I found a way:
IntegrationFlows.from(Jms.messageDriverChannelAdapter(...))
But the problem is that this only accepts the ActiveMQ ConnectionFactory or an AbstractMessageListenerContainer, but no my boot pre-configured JmsListenerContainerFactory !
How should this be implemented in an ultimate way?
JmsListenerContainerFactory is specific for the #JmsListener, it's a higher level abstraction used to configure a DefaultMessageListenerContainer. Boot does not provide an auto configuration option for a raw DefaultMessageListenerContainer; you have to wire it up yourself. But you can still use the Boot properties...
#Bean
public IntegrationFlow flow(ConnectionFactory connectionFactory,
JmsProperties properties) {
return IntegrationFlows.from(Jms.messageDrivenChannelAdapter(container(connectionFactory, properties)))
...
.get();
}
private DefaultMessageListenerContainer container(ConnectionFactory connectionFactory,
JmsProperties properties) {
DefaultMessageListenerContainer container = new DefaultMessageListenerContainer();
container.setConcurrentConsumers(properties.getListener().getConcurrency());
container.setMaxConcurrentConsumers(properties.getListener().getMaxConcurrency());
...
return container;
}
There is even a better approach. I am surprised Gary did not comment it.
There's an out-of-the-box builder called Jms.container(...).
#Bean
public IntegrationFlow jmsMyServiceMsgInboundFlow(ConnectionFactory connectionFactory, MessageConverter jmsMessageConverter, MyService myService, JmsProperties jmsProperties, #Value("${mycompany.jms.destination.my-topic}") String topicDestination){
JmsProperties.Listener jmsInProps = jmsProperties.getListener();
return IntegrationFlows.from(
Jms.messageDrivenChannelAdapter( Jms.container(connectionFactory, topicDestination)
.pubSubDomain(false)
.sessionAcknowledgeMode(jmsInProps .getAcknowledgeMode().getMode())
.maxMessagesPerTask(1)
.errorHandler(e -> e.printStackTrace())
.cacheLevel(0)
.concurrency(jmsInProps.formatConcurrency())
.taskExecutor(Executors.newCachedThreadPool())
.get()))
)
.extractPayload(true)
.jmsMessageConverter(jmsMessageConverter)
.destination(topicDestination)
.autoStartup(true)
//.errorChannel("NOPE")
)
.log(LoggingHandler.Level.DEBUG)
.log()
.handle(myService, "myMethod", e -> e.async(true).advice(retryAdvice()))
.get();
I have a java application written on top of Spring Boot and I can see the metrics being generated through the /metrics management API. I would like to filter the metrics that are being generated (based on metric prefix) and print to stdout OR send the selected metrics to a 3rd party aggregator (not the ones referenced here)
I tried the code suggested by this answer but it didn't result in any metrics being written to the stdout. This is what I added to my Application.java class:
#Bean
#ServiceActivator(inputChannel = "metricsChannel")
public MessageHandler metricsHandler() {
return System.out::println;
}
What is the best way to intercept the metrics on a preconfigured cadence so I can process and write them to stdout or publish them to an aggregator?
Thanks.
Looks like it's a bug in the Spring Boot: https://github.com/spring-projects/spring-boot/issues/5517.
We have to declare something like this ourselves as a workaround:
#Bean
public MessageChannel metricsChannel() {
return new DirectChannel();
}
#Bean
#ExportMetricWriter
public MessageChannelMetricWriter messageChannelMetricWriter() {
return new MessageChannelMetricWriter(metricsChannel());
}
#Bean
#ServiceActivator(inputChannel = "metricsChannel")
public MessageHandler metricsHandler() {
return System.out::println;
}
I'm trying to implement Togglz & Spring using #Configuration beans rather than XML. I'm not sure how to configure the return type of the Configuration bean. For example:
#Configuration
public class SystemClockConfig {
#Bean
public SystemClock plainSystemClock() {
return new PlainSystemClock();
}
#Bean
public SystemClock awesomeSystemClock() {
return new AwesomeSystemClock();
}
#Bean
public FeatureProxyFactoryBean systemClock() {
FeatureProxyFactoryBean proxyFactoryBean = new FeatureProxyFactoryBean();
proxyFactoryBean.setActive(awesomeSystemClock());
proxyFactoryBean.setInactive(plainSystemClock());
proxyFactoryBean.setFeature(Features.AWESOME_SYSTEM_CLOCK.name());
proxyFactoryBean.setProxyType(SystemClock.class);
return proxyFactoryBean;
}
}
The systemClock method returns a FeatureProxyFactoryBean but the clients of this bean require a SystemClock. Of course, the compiler freaks over this.
I imagine it just works when XML config is used. How should I approach it when using a configuration bean?
I'm not an expert for the Java Config configuration style of Spring, but I guess your systemClock() method should return a proxy created with the FeatureProxyFactoryBean. Something like this:
#Bean
public SystemClock systemClock() {
FeatureProxyFactoryBean proxyFactoryBean = new FeatureProxyFactoryBean();
proxyFactoryBean.setActive(awesomeSystemClock());
proxyFactoryBean.setInactive(plainSystemClock());
proxyFactoryBean.setFeature(Features.AWESOME_SYSTEM_CLOCK.name());
proxyFactoryBean.setProxyType(SystemClock.class);
return (SystemClock) proxyFactoryBean.getObject();
}
But I'm not sure if this is the common way to use FactoryBeans with Spring Java Config.
i am working on BIRT reporting tool. which is need to called by spring MVC.
i got one example from spring which is here. in this example, configuration is done via bean. can anyone help me convert this configuration in to xml based configuration ?
#EnableWebMvc
#ComponentScan({ "org.eclipse.birt.spring.core","org.eclipse.birt.spring.example" })
#Configuration
public class BirtWebConfiguration extends WebMvcConfigurerAdapter {
#Override
public void addViewControllers(ViewControllerRegistry registry) {
registry.addViewController("/reports").setViewName("birtView");
}
#Bean
public BirtView birtView() {
BirtView bv = new BirtView();
// bv.setReportFormatRequestParameter("ReportFormat");
// bv.setReportNameRequestParameter("ReportName");
bv.setBirtEngine(this.engine().getObject());
return bv;
}
#Bean
public BeanNameViewResolver beanNameResolver() {
BeanNameViewResolver br = new BeanNameViewResolver();
return br;
}
#Bean
protected BirtEngineFactory engine() {
BirtEngineFactory factory = new BirtEngineFactory();
return factory;
}
}
I wants a similar configuration in xml file.
There's really no tool for extracting Spring annotations to Spring bean context xml file. You'll have to do it by hand, shouldn't be too hard as all the Spring annotations functionality can be duplicated into Spring context xml tags.
if you want to use spingmvc, so no need the configuration files.
my solution is that in Birt Script i call the impl java file like this :
sampleService = new Packages.com.example.warlock.service.SampleServiceImpl();
pojo = new Packages.com.example.warlock.entity.Sample();
iterator = sampleService.getSamples().iterator();
because my SampleService is a interface and SampleServiceImpl is impl java, the two java file are not config as #Bean.
At first i want to get the data from ModelMap but failed, so i skip the controller and straight to call Service, then final call the DAO to get the Data from DB