Before to start understanding to configure the camel with
spring framework and you are new in camel so please go through the below post.
Configure Apache Camel with spring framework:
We will use the same example which we did in previous post.
This demo example ask to use to enter something at command prompt and reply
back to user to same string in capitalize letter.
We are going to create a java string maven project using eclipse Kepler.
1. First we will add the maven dependency
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-core</artifactId>
<version>2.13.0</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-spring</artifactId>
<version>2.13.0</version>
</dependency>
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-stream</artifactId>
<version>2.13.0</version>
</dependency>
</dependencies>
<properties>
<spring.version>4.0.1.RELEASE</spring.version>
</properties>
2.
Create a spring configuration file
<?xml version="1.0"
encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:camel="http://camel.apache.org/schema/spring"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://camel.apache.org/schema/spring
http://camel.apache.org/schema/spring/camel-spring.xsd">
<camelContext xmlns="http://camel.apache.org/schema/spring">
<route>
<from uri="stream:in?promptMessage=Enter
something: " />
<transform>
<simple>${body.toUpperCase()}</simple>
</transform>
<to uri="stream:out"
/>
</route>
</camelContext>
</beans>
As we all are well familiar
with spring configuration file so I just cover only apache camel context.
We
can see that I have added <camelContext> tag with in spring configuration
file.
This is a camel context file where we can add route. In this
example we have add a single route where <from> tag is start point of the
route.
Each route have only single <from> tag and multiple
<to> tag as mentioned below:
<camelContext xmlns="http://camel.apache.org/schema/spring">
<route>
<from uri="stream:in?promptMessage=Enter
something: " />
<to uri="transform"
/>
<to uri="changetojson"
/>
<to uri="stream:out"
/>
</route>
<route>
<from uri="stream:in?promptMessage=Enter
something: " />
<to uri="transform"
/>
<to uri="changetoXML"
/>
<to uri="stream:out"
/>
</route>
</camelContext>
3. Write the java class
public class MyFirstCamelExample
{
public static void main(String[] args)
{
//First load the spring configuration file
AbstractApplicationContext
camelContext = new ClassPathXmlApplicationContext("firstcamelexample.xml");
//Start the camel context
camelContext.start();
// Wait for few second to process the camel for
message exchange between endpoints. If we don’t add this so camel immediately
close the service.
try {
Thread.sleep(60000);
}
catch
(InterruptedException e) {
// TODO Auto-generated
catch block
e.printStackTrace();
}
//Stop the camel context
camelContext.stop();
}
}
Apache Camel: File Component:
Apache camel also provides a support for file operations. I
will write it another blog post to cover file operation but this example just
read the file from one location and write it to console.
<camelContext xmlns="http://camel.apache.org/schema/spring">
<route>
<!-- read input
from the file -->
<from uri="file://c:/test/jigar"
/>
<!-- Write it to
console -->
<to uri="stream:out"
/>
</route>
</camelContext>
We need to add route in camel context. When any file will trigger
at “c:/test/jigar” location, Apache camel file component will take that file
and pass it to next instruction ( print the
file content at console)
Java Class:
package
com.jigarnagar.camel.firstexample;
import
org.springframework.context.support.AbstractApplicationContext;
import
org.springframework.context.support.ClassPathXmlApplicationContext;
public class MyFirstCamelExample
{
public static void main(String[] args)
{
AbstractApplicationContext camelContext
= new
ClassPathXmlApplicationContext("firstcamelexample.xml");
camelContext.start();
try {
Thread.sleep(60000);
}
catch
(InterruptedException e) {
// TODO Auto-generated
catch block
e.printStackTrace();
}
camelContext.stop();
}
}
Happy to see your comment
