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