Camel as a_glue

Camelas a Glue

Project. How we planned it

Project. How we imagine it.

Project. In practice.

Integration project. In practice.

How to handle it?

RTFM.Enterprise Integration Patterns: Designing, Building, and Deploying Messaging Solutions

Specific tool

• Apache Camel• Spring Integration• Enterprise Service Bus (Mule ESB)

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Apache Camel. Pros.

Pros• Lighweight• A lot components• Support many Data Formats• Good community• DSL(XML, Java, Scala, Groovy)• Spring integration

Apache Camel. Cons.

• Messy documentations

Basic example. XML DSLcamel-config.xml<camelContext>………………………………………………….

<route><from uri="servlet:///my_url" /><bean ref=“urlHandler” method=“handle" /><transform><constant>DONE</constant></transform>

</route>………………………………………………….</camelContext>

Basic example. JAVA DSL

public class MyRouteBuilder extends RouteBuilder{

public void configure() { from(" servlet:///my_url "). process(new UrlHandler()).to("direct:b");

} };Orpublic class MyRouteBuilder extends RouteBuilder{

public void configure() { from(" servlet:///my_url "). processRef(“urlHandler”).to("direct:b");

} };

Processor

@Component(“urlHandler”)public class UrlHandler{

public void handle(Exchange ex){ex.getIn();//handle input

}}

More complex example

<route><from uri="activemq:queue:queueName" /><unmarshal ref="xstream-utf8" /><bean ref=“firstProcessor" method="process" /><bean ref=“secondProcessor" method="process" />

…………………………………………………………………………………….<bean ref=“lastProcessor" method="process" /><to uri="direct:anotherRoute" />

</route>

Components• Amazon stack• Apache stack(service miz, fop, cxf,)• DBs(jdbc, jpa, ibatis)• EJB• File(ftp, ftps, file, hdfs)• Google stack(gae, guice, gmail, gtask)• Hazelcast• JMS• JMX• Mail (IMAP, POP)• Queues• Twitter• Many others

Components example

To poll, every 5 sec., all statuses on your home timeline and send to gmail:

Java DSLfrom("twitter://timeline/home?

type=polling&delay=5&consumerKey=[s]&consumerSecret=[s]&accessToken=[s]&accessTokenSecret=[s]").to("gmail://account1@gmail.com")

XML DSL<route>

<from uri="twitter://timeline/home?type=polling&delay=5&consumerKey=[s]&consumerSecret=[s]&accessToken=[s]&accessTokenSecret=[s]"/> <to uri=" gmail://account1@gmail.com "/>

</route>

Data Formats• Standard java serialization• Object marshalling (json, protobuf)• Object xml marshalling (xstream, jaxb, jixb, castor, xmlbeans• Object/XML/Webservice marshalling (SOAP)• Direct JSON / XML marshalling• Flat data structure marshalling (BeanIO, bindy, csv, edi, flatpack

dataformat)• Domain specific marshalling (HL7)• Compression (gzip, zip)• Security (Crypto, PGP, XMLsecurity)• Misc (custom dataformat, rss, syslog, tidymarkup)• Dozer Type Conversion

Marshalling example

<route> <from uri="direct:start"/><marshal ref="myJaxb"/> <to uri="direct:marshalled"/>

</route> <route>

<from uri="direct:marshalled"/> <unmarshal ref="myJaxb"/> <to uri="mock:result"/>

</route>

EIP

• Dynamic Router

• Recipient List

• Message Filter

• Wire Tap• Throttler• Load Balancer• Multicast• Others

Summary

Questions?