#161 - Publish Subscribe Channel realisation.Heavily based on iluwatars Message Channel implementation (#143).

This commit is contained in:
JaXt0r 2015-10-25 07:11:34 +01:00
parent 0a9879a277
commit ac5c1967df
8 changed files with 333 additions and 0 deletions

View File

@ -80,6 +80,7 @@
<module>message-channel</module>
<module>fluentinterface</module>
<module>reactor</module>
<module>publish-subscribe</module>
</modules>
<dependencyManagement>

1
publish-subscribe/.gitignore vendored Normal file
View File

@ -0,0 +1 @@
/target/

Binary file not shown.

After

Width:  |  Height:  |  Size: 27 KiB

View File

@ -0,0 +1,218 @@
<?xml version="1.0" encoding="UTF-8"?>
<class-diagram version="1.1.8" icons="true" always-add-relationships="false" generalizations="true" realizations="true"
associations="true" dependencies="false" nesting-relationships="true">
<class id="1" language="java" name="org.apache.camel.builder.RouteBuilder" project="message-channel"
file="D:/Users/mdaehner/.m2/repository/org/apache/camel/camel-core/2.15.3/camel-core-2.15.3.jar" binary="true"
corner="BOTTOM_RIGHT">
<position height="-1" width="-1" x="269" y="526"/>
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="false"
sort-features="false" accessors="true" visibility="true">
<attributes public="false" package="false" protected="false" private="false" static="true"/>
<operations public="false" package="false" protected="false" private="false" static="false"/>
</display>
</class>
<interface id="2" language="java" name="org.apache.camel.RoutesBuilder" project="message-channel"
file="D:/Users/mdaehner/.m2/repository/org/apache/camel/camel-core/2.15.3/camel-core-2.15.3.jar" binary="true"
corner="BOTTOM_RIGHT">
<position height="-1" width="-1" x="270" y="406"/>
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="false"
sort-features="false" accessors="true" visibility="true">
<attributes public="false" package="false" protected="false" private="false" static="true"/>
<operations public="false" package="false" protected="false" private="false" static="false"/>
</display>
</interface>
<class id="3" language="java" name="org.apache.camel.model.RouteDefinition" project="message-channel"
file="D:/Users/mdaehner/.m2/repository/org/apache/camel/camel-core/2.15.3/camel-core-2.15.3.jar" binary="true"
corner="BOTTOM_RIGHT">
<position height="-1" width="-1" x="574" y="421"/>
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="false"
sort-features="false" accessors="true" visibility="true">
<attributes public="false" package="false" protected="false" private="false" static="true"/>
<operations public="false" package="false" protected="false" private="false" static="false"/>
</display>
</class>
<class id="4" language="java" name="org.apache.camel.model.RoutesDefinition" project="message-channel"
file="D:/Users/mdaehner/.m2/repository/org/apache/camel/camel-core/2.15.3/camel-core-2.15.3.jar" binary="true"
corner="BOTTOM_RIGHT">
<position height="-1" width="-1" x="574" y="526"/>
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="false"
sort-features="false" accessors="true" visibility="true">
<attributes public="false" package="false" protected="false" private="false" static="true"/>
<operations public="false" package="false" protected="false" private="false" static="false"/>
</display>
</class>
<class id="5" language="java" name="org.apache.camel.model.MulticastDefinition" project="message-channel"
file="D:/Users/mdaehner/.m2/repository/org/apache/camel/camel-core/2.15.3/camel-core-2.15.3.jar" binary="true"
corner="BOTTOM_RIGHT">
<position height="-1" width="-1" x="574" y="68"/>
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="false"
sort-features="false" accessors="true" visibility="true">
<attributes public="false" package="false" protected="false" private="false" static="true"/>
<operations public="false" package="false" protected="false" private="false" static="false"/>
</display>
</class>
<class id="6" language="java" name="org.apache.camel.model.OutputDefinition" project="message-channel"
file="D:/Users/mdaehner/.m2/repository/org/apache/camel/camel-core/2.15.3/camel-core-2.15.3.jar" binary="true"
corner="BOTTOM_RIGHT">
<position height="-1" width="-1" x="576" y="164"/>
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="false"
sort-features="false" accessors="true" visibility="true">
<attributes public="false" package="false" protected="false" private="false" static="true"/>
<operations public="false" package="false" protected="false" private="false" static="false"/>
</display>
</class>
<class id="7" language="java" name="org.apache.camel.model.ProcessorDefinition" project="message-channel"
file="D:/Users/mdaehner/.m2/repository/org/apache/camel/camel-core/2.15.3/camel-core-2.15.3.jar" binary="true"
corner="BOTTOM_RIGHT">
<position height="-1" width="-1" x="575" y="284"/>
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="false"
sort-features="false" accessors="true" visibility="true">
<attributes public="false" package="false" protected="false" private="false" static="true"/>
<operations public="false" package="false" protected="false" private="false" static="false"/>
</display>
</class>
<interface id="8" language="java" name="org.apache.camel.CamelContext" project="message-channel"
file="D:/Users/mdaehner/.m2/repository/org/apache/camel/camel-core/2.15.3/camel-core-2.15.3.jar" binary="true"
corner="BOTTOM_LEFT">
<position height="-1" width="-1" x="1086" y="346"/>
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="false"
sort-features="false" accessors="true" visibility="true">
<attributes public="false" package="false" protected="false" private="false" static="true"/>
<operations public="false" package="false" protected="false" private="false" static="false"/>
</display>
</interface>
<interface id="9" language="java" name="org.apache.camel.model.ModelCamelContext" project="message-channel"
file="D:/Users/mdaehner/.m2/repository/org/apache/camel/camel-core/2.15.3/camel-core-2.15.3.jar" binary="true"
corner="BOTTOM_LEFT">
<position height="-1" width="-1" x="1086" y="526"/>
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="false"
sort-features="false" accessors="true" visibility="true">
<attributes public="false" package="false" protected="false" private="false" static="true"/>
<operations public="false" package="false" protected="false" private="false" static="false"/>
</display>
</interface>
<class id="10" language="java" name="org.apache.camel.impl.DefaultCamelContext" project="message-channel"
file="D:/Users/mdaehner/.m2/repository/org/apache/camel/camel-core/2.15.3/camel-core-2.15.3.jar" binary="true"
corner="BOTTOM_RIGHT">
<position height="-1" width="-1" x="885" y="421"/>
<display autosize="true" stereotype="true" package="true" initial-value="false" signature="false"
sort-features="false" accessors="true" visibility="true">
<attributes public="false" package="false" protected="false" private="false" static="true"/>
<operations public="false" package="false" protected="false" private="false" static="false"/>
</display>
</class>
<realization id="11">
<end type="SOURCE" refId="10"/>
<end type="TARGET" refId="9"/>
</realization>
<generalization id="12">
<end type="SOURCE" refId="6"/>
<end type="TARGET" refId="7"/>
</generalization>
<association id="13">
<end type="SOURCE" refId="6" navigable="false">
<attribute id="14" name="outputs">
<position height="0" width="0" x="0" y="0"/>
</attribute>
<multiplicity id="15" minimum="0" maximum="2147483647">
<position height="0" width="0" x="0" y="0"/>
</multiplicity>
</end>
<end type="TARGET" refId="7" navigable="true"/>
<display labels="true" multiplicity="true"/>
</association>
<realization id="16">
<end type="SOURCE" refId="1"/>
<end type="TARGET" refId="2"/>
</realization>
<generalization id="17">
<end type="SOURCE" refId="3"/>
<end type="TARGET" refId="7"/>
</generalization>
<association id="18">
<end type="SOURCE" refId="4" navigable="false">
<attribute id="19" name="camelContext">
<position height="0" width="0" x="0" y="0"/>
</attribute>
<multiplicity id="20" minimum="0" maximum="1">
<position height="0" width="0" x="0" y="0"/>
</multiplicity>
</end>
<end type="TARGET" refId="9" navigable="true"/>
<display labels="true" multiplicity="true"/>
</association>
<association id="21">
<end type="SOURCE" refId="7" navigable="false">
<attribute id="22" name="parent">
<position height="0" width="0" x="0" y="0"/>
</attribute>
<multiplicity id="23" minimum="0" maximum="1">
<position height="0" width="0" x="0" y="0"/>
</multiplicity>
</end>
<end type="TARGET" refId="7" navigable="true"/>
<display labels="true" multiplicity="true"/>
</association>
<association id="24">
<end type="SOURCE" refId="1" navigable="false">
<attribute id="25" name="routeCollection">
<position height="0" width="0" x="0" y="0"/>
</attribute>
<multiplicity id="26" minimum="0" maximum="1">
<position height="0" width="0" x="0" y="0"/>
</multiplicity>
</end>
<end type="TARGET" refId="4" navigable="true"/>
<display labels="true" multiplicity="true"/>
</association>
<association id="27">
<end type="SOURCE" refId="10" navigable="false">
<attribute id="28" name="routeDefinitions">
<position height="0" width="0" x="0" y="0"/>
</attribute>
<multiplicity id="29" minimum="0" maximum="2147483647">
<position height="0" width="0" x="0" y="0"/>
</multiplicity>
</end>
<end type="TARGET" refId="3" navigable="true"/>
<display labels="true" multiplicity="true"/>
</association>
<association id="30">
<end type="SOURCE" refId="3" navigable="false">
<attribute id="31" name="outputs">
<position height="0" width="0" x="0" y="0"/>
</attribute>
<multiplicity id="32" minimum="0" maximum="2147483647">
<position height="0" width="0" x="0" y="0"/>
</multiplicity>
</end>
<end type="TARGET" refId="7" navigable="true"/>
<display labels="true" multiplicity="true"/>
</association>
<generalization id="33">
<end type="SOURCE" refId="9"/>
<end type="TARGET" refId="8"/>
</generalization>
<association id="34">
<end type="SOURCE" refId="4" navigable="false">
<attribute id="35" name="routes">
<position height="0" width="0" x="0" y="0"/>
</attribute>
<multiplicity id="36" minimum="0" maximum="2147483647">
<position height="0" width="0" x="0" y="0"/>
</multiplicity>
</end>
<end type="TARGET" refId="3" navigable="true"/>
<display labels="true" multiplicity="true"/>
</association>
<generalization id="37">
<end type="SOURCE" refId="5"/>
<end type="TARGET" refId="6"/>
</generalization>
<classifier-display autosize="true" stereotype="true" package="true" initial-value="false" signature="false"
sort-features="false" accessors="true" visibility="true">
<attributes public="false" package="false" protected="false" private="false" static="true"/>
<operations public="false" package="false" protected="false" private="false" static="false"/>
</classifier-display>
<association-display labels="true" multiplicity="true"/>
</class-diagram>

View File

@ -0,0 +1,17 @@
---
layout: pattern
title: Publish Subscribe
folder: publish-subscribe
permalink: /patterns/publish-subscribe/
categories: Integration
tags: Java
---
**Intent:** When applications communicate using a messaging system they do it by using logical addresses
of the system, so called Publish Subscribe Channel. The publisher broadcasts a message to all registered Subscriber.
![alt text](./etc/publish-subscribe.png "Publish Subscribe Channel")
**Applicability:** Use the Publish Subscribe Channel pattern when
* two or more applications need to communicate using a messaging system for broadcasts.

24
publish-subscribe/pom.xml Normal file
View File

@ -0,0 +1,24 @@
<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>
<parent>
<groupId>com.iluwatar</groupId>
<artifactId>java-design-patterns</artifactId>
<version>1.7.0</version>
</parent>
<artifactId>publish-subscribe</artifactId>
<dependencies>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-core</artifactId>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-stream</artifactId>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
</dependency>
</dependencies>
</project>

View File

@ -0,0 +1,55 @@
package com.iluwatar.publish.subscribe;
import org.apache.camel.CamelContext;
import org.apache.camel.builder.RouteBuilder;
import org.apache.camel.impl.DefaultCamelContext;
/**
*
* When applications communicate with each other using a messaging system
* they first need to establish a communication channel that will carry the
* data. Message Channel decouples Message producers (publisher) and consumers (subscriber).
* <p>
* The sending application doesn't necessarily know what particular applications
* will end up retrieving it, but it can be assured that the application that
* retrieves the information is interested in that information. This is because
* the messaging system has different Message Channels for different types of
* information the applications want to communicate. When an application sends
* information, it doesn't randomly add the information to any channel available;
* it adds it to a channel whose specific purpose is to communicate that sort of
* information. Likewise, an application that wants to receive particular information
* doesn't pull info off some random channel; it selects what channel to get information
* from based on what type of information it wants.
* <p>
* In this example we use Apache Camel to establish different Message Channels. The first
* one reads from standard input and delivers messages to Direct endpoints (Publish; Broadcast). The other Message
* Channels are established from the Direct component to different Endpoints (Subscriber). No actual messages are sent,
* only the established routes are printed to standard output.
*
*/
public class App {
/**
* Program entry point
*
* @param args command line args
* @throws Exception
*/
public static void main(String[] args) throws Exception {
CamelContext context = new DefaultCamelContext();
context.addRoutes(new RouteBuilder() {
@Override
public void configure() throws Exception {
from("stream:in")
.multicast()
.to("direct:greetings1", "direct:greetings2", "direct:greetings3");
}
});
context.start();
context.getRoutes().stream().forEach((r) -> System.out.println(r));
context.stop();
}
}

View File

@ -0,0 +1,17 @@
package com.iluwatar.publish.subscribe;
import org.junit.Test;
/**
*
* Application test
*
*/
public class AppTest {
@Test
public void test() throws Exception {
String[] args = {};
App.main(args);
}
}