1. Taking Apache Camel
For a Ride
Bruce Snyder
bsnyder@apache.org
3 June 2008 1

2. Integration is Messy!
2

3. System Integration
3

4. Data Formats
4

5. Apache Camel
http://activemq.apache.org/camel/
5

6. What is
Apache
Camel?
6

7. Enterprise Integration Patterns
http://enterpriseintegrationpatterns.com/
7

8. Patterns
8

9. Message Routing
9

10. Language Support
• BeanShell • SQL
• Javascript • XPath
• Groovy • XQuery
• Python • OGNL
• PHP • JSR 223 scripting
• Ruby
10

11. Apache Camel Components
http://activemq.apache.org/camel/components.html
11

12. History of Apache Camel
12

13. The Camel Context
CamelContext context = new DefaultCamelContext();
context.addRoutes(new MyRouteBuilder());
context.start();
<camelContext
xmlns="http://activemq.apache.org/camel/schema/spring">
<package>com.acme.quotes</package>
</camelContext>
13

14. Pattern
Examples
14

15. Patterns Again
15

16. Content Based Router
RouteBuilder builder = new RouteBuilder() {
public void configure() {
from("seda:a").choice().when(header("foo")
.isEqualTo("bar")).to("seda:b")
.when(header("foo").isEqualTo("cheese"))
.to("seda:c").otherwise().to("seda:d");
}
};
16

17. Content Based Router
<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>
17

18. Message Filter
public class MyRouteBuilder extends RouteBuilder {
public void configure() {
from("activemq:topic:Quotes).
filter().xpath("/quote/product = ‘widget’").
to("mqseries:WidgetQuotes");
}
}
18

19. 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>
19

20. Splitter
public class MyRouteBuilder extends RouteBuilder {
public void configure() {
from("file://orders").
splitter(body().tokenize("n")).
to("activemq:Order.Items");
}
}
20

21. Splitter Using XQuery
public class MyRouteBuilder extends RouteBuilder {
public void configure() {
from("file://orders").
splitter().xquery("/order/items").
to("activemq:Order.Items");
}
}
21

22. Aggregator
public class MyRouteBuilder extends RouteBuilder {
public void configure() {
from("activemq:Inventory.Items").
aggregator().xpath("/order/@id").
to("activemq:Inventory.Order");
}
}
22

23. Message Translator
public class MyRouteBuilder extends RouteBuilder {
public void configure() {
from("file://incoming”).
to("xslt:com/acme/mytransform.xsl").
to("http://outgoing.com/foo");
}
}
23

24. Resequencer
public class MyRouteBuilder extends RouteBuilder {
public void configure() {
from("direct:a”).
resequencer(header("JMSPriority")).
to("seda:b");
}
}
24

25. Throttler
public class MyRouteBuilder extends RouteBuilder {
public void configure() {
from("seda:a”).
throttler(3).timePeriodMillis(30000).
to("seda:b");
}
}
25

26. Delayer
public class MyRouteBuilder extends RouteBuilder {
public void configure() {
from("seda:a”).
delayer(header("JMSTimestamp", 3000).
to("seda:b");
}
}
26

27. Combine Patterns
public class MyRouteBuilder extends RouteBuilder {
public void configure() {
from("seda:a”).
resequencer(header("JMSPriority")).
delayer(3000).
to("seda:b");
}
}
27

28. Beans
28

29. Bean
package com.mycompany.beans;
public class MyBean {
public void someMethod(String name) {
...
}
}
<camelContext
xmlns="http://activemq.apache.org/camel/schema/spring">
<package>com.mycompany.beans</package>
</camelContext>
29

30. Bean as a Message Translator
public class MyRouteBuilder extends RouteBuilder {
public void configure() {
from("activemq:Incoming”).
beanRef("myBean").
to("activemq:Outgoing");
}
}
30

31. Bean as a Message Translator
*With Method Name
public class MyRouteBuilder extends RouteBuilder {
public void configure() {
from("activemq:Incoming”).
beanRef("myBean", "someMethod").
to("activemq:Outgoing");
}
}
31

32. Type Conversion
32

33. Type Conversion
@Converter
public class IOConverter {
@Converter
public static InputStream toInputStream(File file)
throws FileNotFoundException {
return new BufferedInputStream(
new FileInputStream(file));
}
}
33

34. Binding Beans to Camel Endpoints
public class Foo {
@MessageDriven(uri="activemq:cheese")
public void onCheese(String name) {
...
}
}
34

35. Binding Method Arguments
public class Foo {
public void onCheese(
@XPath("/foo/bar") String name,
@Header("JMSCorrelationID") String id) {
...
}
}
http://activemq.apache.org/camel/bean-integration.html
35

36. Injecting Endpoints Into Beans
public class Foo {
@EndpointInject(uri="activemq:foo.bar")
ProducerTemplate producer;
public void doSomething() {
if (whatever) {
producer.sendBody("<hello>world!</hello>");
}
}
}
36

37. Spring Remoting - Server Side
<camelContext
xmlns="http://activemq.apache.org/camel/schema/spring">
<export id="sayService"
uri="activemq:MyService"
serviceRef="sayImpl"
serviceInterface="com.acme.MyServiceInterface"/>
</camelContext>
<bean id="sayImpl" class="com.acme.MyServiceImpl"/>
37

38. Spring Remoting - Client Side
<camelContext
xmlns="http://activemq.apache.org/camel/schema/spring">
<proxy id="sayService" serviceUrl="activemq:MyService"
serviceInterface="com.acme.MyServiceInterface"/>
</camelContext>
38

39. Dependency Injection
<camelContext
xmlns="http://activemq.apache.org/camel/schema/spring">
...
</camelContext>
<bean id="activemq"
class="org.apache.camel.component.jms.JmsComponent">
<property name="connectionFactory">
<bean class="org.apache.activemq.ActiveMQConnectionFactory">
<property name="brokerURL"
value="vm://localhost?broker.persistent=false"/>
</bean>
</property>
</bean>
39

40. Business Activity Monitoring (BAM)
40

41. Business Activity Monitoring (BAM)
public class MyActivities extends ProcessBuilder {
public void configure() throws Exception {
// lets define some activities, correlating on an
// XPath query of the message body
ActivityBuilder purchaseOrder = activity("activemq:PurchaseOrders")
.correlate(xpath("/purchaseOrder/@id").stringResult());
ActivityBuilder invoice = activity("activemq:Invoices")
.correlate(xpath("/invoice/@purchaseOrderId").stringResult());
// now lets add some BAM rules
invoice.starts().after(purchaseOrder.completes())
.expectWithin(seconds(1))
.errorIfOver(seconds(2)).to("activemq:FailedProcesses");
}
}
41

42. Ride the Camel!
42

43. Questions?
43