Becoming a Master in Apache Maven 3

Writing programs in Java is cool, its a language thats very powerful which have right amount of flexibility that makes a developers life a hell easy. But when it comes to compiling, building and managing releases of a project its not that easy, it also has the same issues encountered by other programming languages.

To solve this problem, build tools like Apache ANT and Apache Maven have emerged. ANT is very flexible tool which allows users to do almost any thing when it comes to build, maintenance and releases. Having said that since its so flexible its quite hard to configure and manage, every project using ANT uses it in their own way and hence the projects using ANT looses their consistency. At the same time when we look at Apache Maven which is not flexible as ANT by default, but it follows an amazing concept "Convention over configuration" which give that right mix of convention and configuration for you to easily create, build, deploy and even manage releases at an enterprise level.

For examples Maven always works with defaults, and you can easily create and build a maven project just with the follow snippet in the pom.xml file of your project.

<project>
     <modelVersion>4.0.0</modelVersion>
     <groupId>org.example</groupId>
     <artifactId>sample-one</artifactId>
     <version>1.0.0</version>
</project>

And this little configuration is tied up with many conventions

• The Java source code is available at {base-dir}/src/main/java
• Test cases are available at {base-dir}/src/test/java
• A JAR file type of artifact is produced
• Compiled class files are copied into {base-dir}/target/classes
• The final artifact is copied into {base-dir}/target

But there are cases where we need to go a step ahead and break the rules with reasons ! And in any case if we need to change the above defaults its just a matter of adding the Maven Build Plugin and the artifact type to the project tag as below.

<project>
     <modelVersion>4.0.0</modelVersion>
     <groupId>org.example</groupId>
     <artifactId>sample-one</artifactId>
     <version>1.0.0</version>
     <packaging>jar</packaging>
     <build>
         <sourceDirectory>${basedir}/src/main/java</sourceDirectory>
         <testSourceDirectory>${basedir}/src/test/java</testSourceDirectory>
         <outputDirectory>${basedir}/target/classes</outputDirectory>
     </build>
</project>

I came across this great book "Mastering Apache Maven 3" by Prabath Siriwardena that give you all the bits and pieces from getting started to eventually becoming a master in Maven. From this you will get to know the fundamentals and when to break the conventions with reasons. This helps you to develop and manage large, complex projects with confidence by providing an enterprise level knowledge to manage the whole Maven infrastructure.

This book covers Maven Configuration from the basics, discussing how to construct and build a  Maven project, manage Build Lifecycles, introduce useful functionalities through Maven Plugins and helps you to write your own custom plugins when needed. It also provide steps on building distributable archives using Maven Assemblies which adheres to a user-defined layout and structure,   demonstrate the usage of  Maven Archetypes for easily construct Maven projects and steps to create new Archetypes to help your developers and customers to quickly start on your project type without any configurations and replicated work. Further it also helps you to host and manage your Maven artifacts in repositories using Maven Repository Management, and most importantly explains you the Best Practices to keep your projects in line with enterprise standards.

Adding Siddhi extensions when using Siddhi as a Java library

You can write Siddhi extensions and run them in WSO2 CEP as given : https://docs.wso2.com/display/CEP310/Writing+Extensions+to+Siddhi

But if you are using Siddhi as a Java library then you can add then to SiddhiManager as follows

        List extensionClasses = new ArrayList();

        extensionClasses.add(org.wso2.siddhi.core.query.processor.window.UniqueWindowProcessorExt.class);

        

        SiddhiConfiguration siddhiConfiguration = new SiddhiConfiguration();

        siddhiConfiguration.setSiddhiExtensions(extensionClasses);

        

        SiddhiManager siddhiManager = new SiddhiManager(siddhiConfiguration);  

Without restart: Enabling WSO2 ESB as a JMS Consumer of WSO2 MB

WSO2 ESB 4.8.1 & WSO2 MB 2.2.0 documentations have information on how to configure WSO2 ESB as a JMS Consumer of WSO2 MB queues and topics. But they do not point out a way to do this without restarting ESB server.

In this blog post we'll solve this issue.

With this method we will be able to create new queues in WSO2 MB and consume them from WSO2 ESB without restarting it.

Configure the WSO2 Message Broker

• Offset the port of WSO2 MB to '1'  
• Copy andes-client-*.jar and geronimo-jms_1.1_spec-*.jar from $MB_HOME/client-lib to $ESB_HOME/repository/components/lib 
• Start the WSO2 MB

Configure the WSO2 Enterprise Service Bus

• Edit the $ESB_HOME/repository/conf/jndi.properties file (comment or delete any existing configuration)

connectionfactory.QueueConnectionFactory = amqp://admin:admin@clientID/carbon?brokerlist='tcp://localhost:5673'
connectionfactory.TopicConnectionFactory = amqp://admin:admin@clientID/carbon?brokerlist='tcp://localhost:5673'

• Edit the $ESB_HOME/repository/conf/axis2.xml file and uncomment the JMS Sender and JMS Listener configuration for WSO2 Message Broker 
• Start the WSO2 ESB 

Create Proxy Service

The Proxy Service name will become the queue name in WSO2 MB. If you already have a queue in MB and if you want to listen to that queue, then set that queue name as the proxy service name. Here I'm using 'JMSConsumerProxy' as the queue name and the proxy service name.

<?xml version="1.0" encoding="UTF-8"?> 
<proxy xmlns="http://ws.apache.org/ns/synapse" 
       name="JMSConsumerProxy" 
       transports="jms" 
       statistics="disable" 
       trace="disable" 
       startOnLoad="true"> 
   <target> 
      <inSequence> 
         <property name="Action" 
                   value="urn:placeOrder" 
                   scope="default" 
                   type="STRING"/> 
         <log level="full"/> 
         <send> 
            <endpoint> 
               <address uri="http://localhost:9000/services/SimpleStockQuoteService"/> 
            </endpoint> 
         </send> 
      </inSequence> 
      <outSequence> 
         <drop/> 
      </outSequence> 
   </target> 
   <description/> 
</proxy> 

Testing the scenario

• Inside $ESB_HOME/samples/axis2Server/src/SimpleStockQuoteService run ant 
• Now start the Axis2 Server inside $ESB_HOME/samples/axis2Server (run the relevant command line script) 
• Log into the WSO2 Message Broker Management Console and navigate to Browse Queues 
• Find a Queue by the name JMSConsumerProxy 
• Publish 1 message to the JMSConsumerProxy with payload (this has to be done in the Message Broker Management Console) 

<ser:placeOrder xmlns:ser="http://services.samples" xmlns:xsd="http://services.samples/xsd"> 
    <ser:order> 
        <xsd:quantity>4</xsd:quantity> 
    </ser:order> 
</ser:placeOrder>

• Observe the output on the Axis2 Server and WSO2 ESB console.

Hope this helped you :) 

Getting inside out of Social Data using WSO2 BAM & WSO2 CEP

We engage in Social Media, but have we ever analysed the data it contains?

Why we need to analyse?
Can it help us to make prompt business decisions?
How we can do that?

I have done a screencast to answer all these,
using WSO2 Business Activity Monitor (2.4.0) and WSO2 Complex Event Processor (3.0.0).

Integrating WSO2 BAM & WSO2 CEP

This post demonstrate how we can integrate both WSO2 BAM and WSO2 CEP and run them as a single instance.

To integrate both WSO2 BAM and WSO2 CEP we need to download BAM and install the CEP features form the WSO2 p2repo. Here I have used WSO2 BAM 2.2.0 and 4.0.7 p2repo. Follow the wiki link to get to know how to install new features to existing products.

Testing the installation.
To test the instillation add broker-manager-config.xml to repository/conf/, and add axis2_client.xml to repository/conf/axis2/.
Here axis2_client.xml has the email sender information, and I'm using a demo email account for this.

Then create a directory called 'cepbuckets' in repository/deployment/server/ and add bam-cep-kpi-analyzer.xml there.
In bam-cep-kpi-analyzer.xml, you will be able to find a line

<cep:output brokerName="emailBroker" topic="wso2cep.demo@gmail.com/Phone Purchase Notification">

Change "wso2cep.demo@gmail.com" to the endpoint use email ID, who needs to receive the notification.

Now if you run the KIP-analyser sample of BAM all the events that have totalPrice>350000 and quantity>3 will be notified to the user.