Camel: transform message using Data formats

Camel provide a pluggable DataFormat for a wide range of data models.

At the time of writing this post, below data formats are supported by camel.

Standard JVM object marshalling

a.   Serialization

b.   String

Object marshalling

a.   Avro

b.   Boon

c.    Hessian

d.   JSON

e.   Protobuf

f.     YAML

Object/XML marshalling

a.   Castor

b.   JAXB

c.    XmlBeans

d.   XStream

e.   JiBX

f.     Jackson XML

Object/XML/Webservice marshalling

a.   SOAP

Direct JSON / XML marshalling

a.   XmlJson

Flat data structure marshalling

a.   BeanIO

b.   Bindy

c.    CSV

d.   EDI

e.   Flatpack DataFormat

f.     uniVocity-parsers formats

Domain specific marshalling

a.   HL7 DataFormat

Compression

a.   GZip data format

b.   Zip DataFormat

c.    Zip File DataFormat

d.   LZF Data Format

e.   Tar DataFormat

Security

a.   Crypto

b.   PGP

c.    XMLSecurity DataFormat

Misc.

a.   Base64

b.   Custom DataFormat - to use your own custom implementation

c.    MIME-Multipart

d.   RSS

e.   TidyMarkup

f.     Syslog

g.   ICal

h.   Barcode - to read and generate barcodes (QR-Code, PDF417, ...)

I will explain csv file marshalling example here. In later posts, I will cover couple of data formats followed by custom data format.

Let’s implement an application, such that it reads a csv file that contains number of orders (each row of csv file represents an order), we need to read each order and send them as list of orders to the jms queue.

I am going to use ActiveMQ for this tutorial.

Setup ActiveMQ

I would recommend you to go through my below post to setup the activeMQ.

https://self-learning-java-tutorial.blogspot.com/2018/08/installing-and-setting-up-activemq.html

Once you setup activeMQ, loginto the admin console by hitting below url.

http://localhost:8161/admin/

Use below credentials to login to the admin console.

UserName: admin

Password: admin

You can see below kind of user interface.

Setup Eclipse Maven Project

Create new maven project 'camelCSVDataFormat'. Project structure looks like below.

Open pom.xml and update maven dependencies.

pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 <modelVersion>4.0.0</modelVersion>
 <groupId>camelCSVDataFormat</groupId>
 <artifactId>camelCSVDataFormat</artifactId>
 <version>1</version>

 <dependencies>
  <!-- https://mvnrepository.com/artifact/org.apache.camel/camel-jms -->
  <dependency>
   <groupId>org.apache.camel</groupId>
   <artifactId>camel-jms</artifactId>
   <version>2.22.1</version>
  </dependency>

  <!-- https://mvnrepository.com/artifact/org.apache.camel/camel-core -->
  <dependency>
   <groupId>org.apache.camel</groupId>
   <artifactId>camel-core</artifactId>
   <version>2.22.1</version>
  </dependency>

  <!-- https://mvnrepository.com/artifact/org.apache.activemq/activemq-all -->
  <dependency>
   <groupId>org.apache.activemq</groupId>
   <artifactId>activemq-all</artifactId>
   <version>5.15.6</version>
  </dependency>

  <!-- https://mvnrepository.com/artifact/org.apache.camel/camel-csv -->
  <dependency>
   <groupId>org.apache.camel</groupId>
   <artifactId>camel-csv</artifactId>
   <version>2.22.1</version>
  </dependency>


 </dependencies>
</project>

Create new package com.sample.app.routes and define FileCopyRoute.java.

FileCopyRoute.java

package com.sample.app.routes;

import org.apache.camel.Exchange;
import org.apache.camel.Processor;
import org.apache.camel.builder.RouteBuilder;

public class FileCopyRoute extends RouteBuilder {

 @Override
 public void configure() throws Exception {
  String sourceFolder = "file:C:\\Users\\Public\\orders\\csvFiles";
  String jmsOrderQ = "demoJMS:queue:orderQueue";

  from(sourceFolder).unmarshal().csv().to(jmsOrderQ);

  from(jmsOrderQ).process(new Processor() {

   @Override
   public void process(Exchange exchange) throws Exception {
    String data = exchange.getIn().getBody(String.class);
    System.out.println("Received order : " + data);
   }

  });

 }

}

C:\\Users\\Public\\orders\\csvFiles contain one csv file 'orders.csv'.

orders.csv

order123,prod54,5

order123,prod768,1

order124,prod1,8

order125,prod1,2

Define class Application.java in package com.sample.app.

Application.java

package com.sample.app;

import java.util.concurrent.TimeUnit;

import javax.jms.ConnectionFactory;

import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.camel.CamelContext;
import org.apache.camel.component.jms.JmsComponent;
import org.apache.camel.impl.DefaultCamelContext;

import com.sample.app.routes.FileCopyRoute;

public class Application {
 public static void main(String args[]) throws Exception {
  CamelContext context = new DefaultCamelContext();

  ConnectionFactory connectionFactory = new ActiveMQConnectionFactory("tcp://localhost:61616");

  context.addComponent("demoJMS", JmsComponent.jmsComponentAutoAcknowledge(connectionFactory));

  context.addRoutes(new FileCopyRoute());

  context.start();

  TimeUnit.MINUTES.sleep(1);

  context.stop();
 }
}

unmarshal method read the csv file line by line and store all lines in the message body as a java.util.List<List> type.

Run Application.java, you can see below messages in console.

Received order : [[order123, prod54, 5], [order123, prod768, 1], [order124, prod1, 8], [order125, prod1, 2]]

You can observe the same in activeMq queues window.

Total project structure looks like below.

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