Support RxJava module
- Add a way to enable `RxJava` module
- Add `EnableRxJavaModule` annotation that inherits `EnableModule` for `Processor` type.
- It also registers the custom `MessageHandler` that sets up RxJava `Observable/Subscriber` to process the incoming message reactively.
- Introduce `RxJavaProcessor` that is expected to be implemented by the module author with the input/output being `Observable`. This processor is autowired into the message handler registered above.
- Add moving average sample
Add project `spring-cloud-stream-rxjava`
- This project extends `spring-cloud-stream` so that any RxJava processing module would have this as a dependency
This commit is contained in:
Ilayaperumal Gopinathan
committed by
Marius Bogoevici
Marius Bogoevici
parent
0debc7aec3
commit
2b1ccc4c7c
32
spring-cloud-stream-rxjava/pom.xml
Normal file
32
spring-cloud-stream-rxjava/pom.xml
Normal file
@@ -0,0 +1,32 @@
|
||||
<?xml version="1.0" encoding="UTF-8"?>
|
||||
<project xmlns="http://maven.apache.org/POM/4.0.0"
|
||||
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
|
||||
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
|
||||
<modelVersion>4.0.0</modelVersion>
|
||||
|
||||
<artifactId>spring-cloud-stream-rxjava</artifactId>
|
||||
<packaging>jar</packaging>
|
||||
<name>spring-cloud-stream-rxjava</name>
|
||||
<description>RxJava support for spring cloud stream modules</description>
|
||||
|
||||
<parent>
|
||||
<groupId>org.springframework.cloud</groupId>
|
||||
<artifactId>spring-cloud-stream-parent</artifactId>
|
||||
<version>1.0.0.BUILD-SNAPSHOT</version>
|
||||
</parent>
|
||||
|
||||
<dependencies>
|
||||
<dependency>
|
||||
<groupId>org.springframework.cloud</groupId>
|
||||
<artifactId>spring-cloud-stream</artifactId>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>org.springframework.integration</groupId>
|
||||
<artifactId>spring-integration-core</artifactId>
|
||||
</dependency>
|
||||
<dependency>
|
||||
<groupId>io.reactivex</groupId>
|
||||
<artifactId>rxjava</artifactId>
|
||||
</dependency>
|
||||
</dependencies>
|
||||
</project>
|
||||
@@ -0,0 +1,43 @@
|
||||
/*
|
||||
* Copyright 2015 the original author or authors.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
|
||||
package org.springframework.cloud.stream.annotation.rxjava;
|
||||
|
||||
import java.lang.annotation.Documented;
|
||||
import java.lang.annotation.ElementType;
|
||||
import java.lang.annotation.Inherited;
|
||||
import java.lang.annotation.Retention;
|
||||
import java.lang.annotation.RetentionPolicy;
|
||||
import java.lang.annotation.Target;
|
||||
|
||||
import org.springframework.cloud.stream.annotation.EnableBinding;
|
||||
import org.springframework.cloud.stream.messaging.Processor;
|
||||
import org.springframework.context.annotation.Import;
|
||||
|
||||
/**
|
||||
* Annotation that identifies the class as RxJava processor module. The class that has {@link EnableRxJavaProcessor}
|
||||
* annotated is expected to provide a bean that implements {@link RxJavaProcessor}.
|
||||
*
|
||||
* @author Ilayaperumal Gopinathan
|
||||
*/
|
||||
@Target(ElementType.TYPE)
|
||||
@Retention(RetentionPolicy.RUNTIME)
|
||||
@Documented
|
||||
@Inherited
|
||||
@EnableBinding(Processor.class)
|
||||
@Import(RxJavaProcessorConfiguration.class)
|
||||
public @interface EnableRxJavaProcessor {
|
||||
}
|
||||
@@ -0,0 +1,30 @@
|
||||
/*
|
||||
* Copyright 2015 the original author or authors.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
|
||||
package org.springframework.cloud.stream.annotation.rxjava;
|
||||
|
||||
import rx.Observable;
|
||||
|
||||
/**
|
||||
* Marker interface that RxJava processor module uses to provide the implementation bean.
|
||||
*
|
||||
* @author Mark Pollack
|
||||
* @author Ilayaperumal Gopinathan
|
||||
*/
|
||||
public interface RxJavaProcessor<I, O> {
|
||||
|
||||
Observable<O> process(Observable<I> input);
|
||||
}
|
||||
@@ -0,0 +1,43 @@
|
||||
/*
|
||||
* Copyright 2015 the original author or authors.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
package org.springframework.cloud.stream.annotation.rxjava;
|
||||
|
||||
import org.springframework.beans.factory.annotation.Autowired;
|
||||
import org.springframework.cloud.stream.messaging.Processor;
|
||||
import org.springframework.context.annotation.Bean;
|
||||
import org.springframework.context.annotation.Configuration;
|
||||
import org.springframework.integration.annotation.ServiceActivator;
|
||||
import org.springframework.messaging.MessageHandler;
|
||||
|
||||
/**
|
||||
* Configuration class for RxJava module support.
|
||||
*
|
||||
* @author Ilayaperumal Gopinathan
|
||||
*/
|
||||
@Configuration
|
||||
public class RxJavaProcessorConfiguration {
|
||||
|
||||
@Autowired
|
||||
RxJavaProcessor processor;
|
||||
|
||||
@ServiceActivator(inputChannel = Processor.INPUT)
|
||||
@Bean
|
||||
public MessageHandler subjectMessageHandler() {
|
||||
SubjectMessageHandler messageHandler = new SubjectMessageHandler(processor);
|
||||
messageHandler.setOutputChannelName(Processor.OUTPUT);
|
||||
return messageHandler;
|
||||
}
|
||||
}
|
||||
@@ -0,0 +1,116 @@
|
||||
/*
|
||||
* Copyright 2015 the original author or authors.
|
||||
*
|
||||
* Licensed under the Apache License, Version 2.0 (the "License");
|
||||
* you may not use this file except in compliance with the License.
|
||||
* You may obtain a copy of the License at
|
||||
*
|
||||
* http://www.apache.org/licenses/LICENSE-2.0
|
||||
*
|
||||
* Unless required by applicable law or agreed to in writing, software
|
||||
* distributed under the License is distributed on an "AS IS" BASIS,
|
||||
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
||||
* See the License for the specific language governing permissions and
|
||||
* limitations under the License.
|
||||
*/
|
||||
|
||||
package org.springframework.cloud.stream.annotation.rxjava;
|
||||
|
||||
import org.slf4j.Logger;
|
||||
import org.slf4j.LoggerFactory;
|
||||
|
||||
import org.springframework.beans.factory.DisposableBean;
|
||||
import org.springframework.integration.handler.AbstractMessageProducingHandler;
|
||||
import org.springframework.messaging.Message;
|
||||
import org.springframework.messaging.support.MessageBuilder;
|
||||
import org.springframework.util.Assert;
|
||||
import org.springframework.util.ClassUtils;
|
||||
|
||||
import rx.Observable;
|
||||
import rx.Subscription;
|
||||
import rx.functions.Action0;
|
||||
import rx.functions.Action1;
|
||||
import rx.subjects.PublishSubject;
|
||||
import rx.subjects.SerializedSubject;
|
||||
import rx.subjects.Subject;
|
||||
|
||||
/**
|
||||
* Adapts the item at a time delivery of a {@link org.springframework.messaging.MessageHandler}
|
||||
* by delegating processing to a {@link Observable}.
|
||||
* <p/>
|
||||
* The outputStream of the processor is used to create a message and send it to the output channel. If the
|
||||
* input channel and output channel are connected to the {@link org.springframework.cloud.stream.binder.Binder},
|
||||
* then data delivered to the input stream via a call to onNext is invoked on the dispatcher thread of the binder
|
||||
* and sending a message to the output channel will involve IO operations on the binder.
|
||||
* <p/>
|
||||
* The implementation uses a SerializedSubject. This has the advantage that the state of the Observabale
|
||||
* can be shared across all the incoming dispatcher threads that are invoking onNext. It has the disadvantage
|
||||
* that processing and sending to the output channel will execute serially on one of the dispatcher threads.
|
||||
* <p/>
|
||||
* The use of this handler makes for a very natural first experience when processing data. For example given
|
||||
* the stream <code></code>http | rxjava-processor | log</code> where the <code>rxjava-processor</code> does a
|
||||
* <code>buffer(5)</code> and then produces a single value. Sending 10 messages to the http source will
|
||||
* result in 2 messages in the log, no matter how many dispatcher threads are used.
|
||||
* <p/>
|
||||
* You can modify what thread the outputStream subscriber, which does the send to the output channel,
|
||||
* will use by explicitly calling <code>observeOn</code> before returning the outputStream from your processor.
|
||||
* <p/>
|
||||
|
||||
* All error handling is the responsibility of the processor implementation.
|
||||
*
|
||||
* @author Mark Pollack
|
||||
* @author Ilayaperumal Gopinathan
|
||||
*/
|
||||
@SuppressWarnings({"unchecked", "rawtypes"})
|
||||
public class SubjectMessageHandler extends AbstractMessageProducingHandler implements DisposableBean {
|
||||
|
||||
private final Logger logger = LoggerFactory.getLogger(getClass());
|
||||
|
||||
@SuppressWarnings("rawtypes")
|
||||
private final RxJavaProcessor processor;
|
||||
|
||||
private final Subject subject;
|
||||
|
||||
private final Subscription subscription;
|
||||
|
||||
@SuppressWarnings({"unchecked", "rawtypes"})
|
||||
public SubjectMessageHandler(RxJavaProcessor processor) {
|
||||
Assert.notNull(processor, "RxJava processor must not be null.");
|
||||
this.processor = processor;
|
||||
subject = new SerializedSubject(PublishSubject.create());
|
||||
Observable<?> outputStream = processor.process(subject);
|
||||
subscription = outputStream.subscribe(new Action1<Object>() {
|
||||
@Override
|
||||
public void call(Object outputObject) {
|
||||
if (ClassUtils.isAssignable(Message.class, outputObject.getClass())) {
|
||||
getOutputChannel().send((Message) outputObject);
|
||||
}
|
||||
else {
|
||||
getOutputChannel().send(MessageBuilder.withPayload(outputObject).build());
|
||||
}
|
||||
}
|
||||
}, new Action1<Throwable>() {
|
||||
@Override
|
||||
public void call(Throwable throwable) {
|
||||
logger.error(throwable.getMessage(), throwable);
|
||||
}
|
||||
}, new Action0() {
|
||||
@Override
|
||||
public void call() {
|
||||
logger.error("Subscription close for [" + subscription + "]");
|
||||
}
|
||||
});
|
||||
}
|
||||
|
||||
|
||||
@Override
|
||||
//todo: support module input type
|
||||
protected void handleMessageInternal(Message<?> message) throws Exception {
|
||||
subject.onNext(message.getPayload());
|
||||
}
|
||||
|
||||
@Override
|
||||
public void destroy() throws Exception {
|
||||
subscription.unsubscribe();
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user