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About author
• Apache CXF commiter and PMC member
• Apache Camel commiter and PMC member
Riding Apache Camel
•What's Camel
•EIP Examples
•Beans, Type Conversion , Data Format
•Some tips of Camel Riding
What is Camel?
•A Camel can carry 4 times as much load as other beasts of burden!
•Apache Camel is a powerful Spring based Integration Framework.
•Camel implements the Enterprise Integration Patterns allowing you to configure routing and mediation rules in either a Java based Domain Specific Language (or Fluent API) or via Spring based Xml Configuration files. Either approaches mean you get smart completion of routing rules in your IDE whether in your Java or XML editor.
•Apache Camel uses URIs so that it can easily work directly with any kind of Transport or messaging model such as HTTP, ActiveMQ, JMS, JBI, MINA or CXF together with working with pluggable Data Format options. Apache Camel is a small library which has minimal dependencies for easy embedding in any Java application.
Book by Gregor & Bobby!
Message Routing
Message Routing in EIP
Camel Components
Simple Routing
More Simple Routing
Pipeline
Multicast Routing
Some examples of the EIP implemation
Message Filter
<camelContext xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="activemq:topic:Quotes"/> <filter> <xpath>/quote/product = ‘widget’</xpath> <to uri="mqseries:WidgetQuotes"/> </filter> </route> </camelContext>
Message Filter
from("activemq:topic:Quotes). filter().xpath("/quote/product = ‘widget’"). to("mqseries:WidgetQuotes");
Language Support For Message Processing
• BeanShell
• Javascript
• Groovy
• Python
• PHP
• Ruby
• JSP EL
• OGNL
• SQL
• Xpath
• XQuery
<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd http://activemq.apache.org/camel/schema/spring http://activemq.apache.org/camel/schema/spring/camel-spring.xsd"> <camelContext xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="activemq:topic:Quotes"/> <filter> <xpath>/quote/product = ‘widget’</xpath> <to uri="mqseries:WidgetQuotes"/> </filter> </route> </camelContext>
</beans>
Message Filter : Spring XML
Message Filter : Java Complete
package com.acme.quotes;
import org.apache.camel.builder.RouteBuilder;
public class MyRouteBuilder extends RouteBuilder { public void configure() {
// forward widget quotes to MQSeries from("activemq:topic:Quotes). filter().xpath("/quote/product = ‘widget’"). to("mqseries:WidgetQuotes"); }}
CamelContext context = new DefaultCamelContext();context.addRoutes(new MyRouteBuilder());context.start();
Starting the CamelContext
<camelContext id="camel" xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="direct:start"/> <choice> <when> <xpath>$destination = 'firstChoice'</xpath> <to uri="mock:matched"/> </when> <otherwise> <to uri="mock:notMatched"/> </otherwise> </choice> </route> </camelContext>
Content Base Router
from("activemq:NewOrders”). choice().when("/quote/product = ‘widget’"). to("activemq:Orders.Widgets"). choice().when("/quote/product = ‘gadget’"). to("activemq:Orders.Gadgets"). otherwise().to("activemq:Orders.Bad");
<camelContext xmlns="http://activemq.apache.org/camel/schema/spring"> <route> <from uri="activemq:NewOrders"/> <choice> <when> <xpath>/order/product = 'widget'</xpath> <to uri="activemq:Orders.Widgets"/> </when> <when> <xpath>/order/product = 'gadget'</xpath> <to uri="activemq:Orders.Gadgets"/> </when> <otherwise> <to uri="activemq:Orders.Bad"/> </otherwise> </choice> </route> </camelContext>
Content Based Router
How camel do this routing work ?•Camel Components
•Camel Endpoints
•Camel Consumer
•Camel Producer
•Camel-Core
How camel do this routing work ?
http://activemq.apache.org/camel/architecture.html
Beans
Bean as a Message Translator
from("activemq:Incoming”). beanRef("myBeanName"). to("activemq:Outgoing");
Bean
public class Foo {
public void someMethod(String name) { ... }}
Bean as a Message Translator with method name
from("activemq:Incoming”). beanRef("myBeanName", "someMethod"). to("activemq:Outgoing");
public class Foo {
@MessageDriven(uri="activemq:cheese") public void onCheese(String name) { ... }}
Binding Beans to Camel Endpoints
public class Foo {
public void onCheese( @XPath("/foo/bar") String name, @Header("JMSCorrelationID") String id) { ... }}
Binding Method Arguments
for more annotations seehttp://activemq.apache.org/camel/bean-integration.html
Type Conversion
package com.acme.foo.converters;
import org.apache.camel.Converter;import java.io.*;
@Converterpublic class IOConverter {
@Converter public static InputStream toInputStream(File file) throws FileNotFoundException { return new BufferedInputStream(new FileInputStream(file)); }}
Type Conversion
# META-INF/services/org/apache/camel/TypeConverter
com.acme.foo.converters
protected RouteBuilder createRouteBuilder() { return new RouteBuilder() { public void configure() { from("direct:start").convertBodyTo(InputStream.class).to("mock:result"); } }; } protected RouteBuilder createRouteBuilder() { return new RouteBuilder() { public void configure() { from("direct:start").process(new Processor() { public void process(Exchange exchange) { Message in = exchange.getIn(); in.setBody(in.getBody(InputStream.class)); } }).to("mock:result"); }; }
Type Conversion
Data Format
from("activemq:QueueWithJavaObjects). marshal().jaxb(). to("mqseries:QueueWithXmlMessages");
from("activemq:QueueTestMessage). marshal().zip(). to("mqseries:QueueWithCompressMessage");
from("activemq:QueueWithXmlMessages). unmarshal().jaxb(). to("mqseries:QueueWithJavaObjects");
Riding tips of camel
Camel Riding from Java
•/META-INF/spring/camelContext.xml
•set the CLASSPATH
•java org.apache.camel.spring.Main
Maven Tooling
<project>... <build> <plugins> <plugin> <groupId>org.apache.camel</groupId> <artifactId>camel-maven-plugin</artifactId> </plugin> </plugins> </build> <reporting> <plugins> <plugin> <groupId>org.apache.camel</groupId> <artifactId>camel-maven-plugin</artifactId> </plugin> </plugins> </reporting></project>
mvn camel:run
Maven Plugin Site Report
Writing You Own Component
•Component
•Endpoint
•Consumer
•Provider
Where would I use Camel?
•standalone or in any Spring application
•inside ActiveMQ’s JMS client or the broker
•inside your ESB such as ServiceMix via the servicemix-camel Service Unit
•inside CXF either as a transport or reusing CXF inside Camel
How to write your routing rule in Camel
•What's the magic of from, to, choice ......
• /camel-core/src/main/java/org/apache/camel/model
•Implementing it in DSL way
• Defining the type class that you want
•Implementing it in a Spring configuration way
• Adding the annotation for JAXB consuming
Questions?
Let's take a look at Camel-CXF example
•Open eclipse and go to code please
•What does Camel-CXF example have ?
•Multi-binding and Multi-transport supporting
•LoadBalancing
•JAXWS WebSerivce Provider API
Where do I get more info?
please do take Camel for a ride!
http://activemq.apache.org/camel/
don’t get the hump! :-)
