Spring Integration Channels :Lab-1

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Here we will understand publisher and subscriber interaction b/w channels using java project with scenarios.

Pom.xml

<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>	<groupId>com.intertech.si</groupId>	<artifactId>lab1-channels</artifactId>	<version>0.0.1-SNAPSHOT</version>	<name>Spring Integration Lab 1</name>	<description>Lab 1 - using channels</description>	<properties>		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>		<springframework.version>4.0.4.RELEASE</springframework.version>		<spring.integration.version>4.0.0.RELEASE</spring.integration.version>		<spring.integration.xml.version>4.0.0.RELEASE</spring.integration.xml.version>		<log4j.version>1.2.17</log4j.version>	</properties>	<dependencies>		<dependency>			<groupId>org.springframework.integration</groupId>			<artifactId>spring-integration-core</artifactId>			<version>${spring.integration.version}</version>		</dependency>		<dependency>			<groupId>org.springframework.integration</groupId>			<artifactId>spring-integration-stream</artifactId>			<version>${spring.integration.version}</version>		</dependency>		<dependency>			<groupId>log4j</groupId>			<artifactId>log4j</artifactId>			<version>${log4j.version}</version>		</dependency>	</dependencies></project>

Spring integration channel registration

spring-integration-channels.xml

<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans"	xmlns:int="http://www.springframework.org/schema/integration"	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:int-stream="http://www.springframework.org/schema/integration/stream"	xsi:schemaLocation="	http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd	http://www.springframework.org/schema/integration http://www.springframework.org/schema/integration/spring-integration.xsd	http://www.springframework.org/schema/integration/stream http://www.springframework.org/schema/integration/stream/spring-integration-stream.xsd">	<!-- message producer / a Spring Integration wrapped Java Standard input 		stream -->	<int-stream:stdin-channel-adapter id="producer"		channel="messageChannel" />	<!-- a pair of message consumers / a pair of Spring Integration wrapped 		Java Standard output streams -->	<int-stream:stdout-channel-adapter		id="consumer1" channel="messageChannel" append-newline="true" />	<int-stream:stdout-channel-adapter		id="consumer2" channel="messageChannel" append-newline="true" />	<int:poller id="defaultPoller" default="true"		max-messages-per-poll="5" fixed-rate="200" />	<!-- a pub/sub message channel -->	<int:publish-subscribe-channel id="messageChannel" /></beans>

Main container loader class which will load all the beans

Startup.java

import org.springframework.context.support.ClassPathXmlApplicationContext;public class Startup {	@SuppressWarnings({ "resource", "unused" })	// @SuppressWarnings({ "resource" })	public static void main(String[] args) {		ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(				"/META-INF/spring/si-components.xml");		while (true) {		}			}}

Here If we run Sratup.java class then we have to enter message which means we are publishing message using console which is producer and If you see xml there are 2 consumers which are consuming messgae.

So if i enter deepak on console then deppak will be prited twice because there are 2 subscribers(consumers) here.

Output:

log4j:WARN No appenders could be found for logger (org.springframework.core.env.StandardEnvironment).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Contanier started…..
Deepak
Deepak
Deepak

Please find below GIT URL for source code of this Lab

https://github.com/techstudioonline/spring-integration/commit/af6a29342c5a39fa4e56f96b6342f3faec1310be

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