Saturday, July 9, 2011

Weblogic JMS Basics

Slide 28
    The Java Messaging Service (JMS) is a Java Message Oriented Middleware (MOM) API for sending messages between two or more clients. To use JMS, we should have a JMS provider that can manage the sessions and queues. In OSB, weblogic server is the JMS provider.
JMS Provider - An implementation of the JMS interface for a Message Oriented Middleware (MOM)
JMS Client - An application / process which can either produce or consume messages
JMS Message - The data which is transferred between JMS clients
JMS Queue - A space where the messages will be saved for sending or receiving. It will be either saved in the  Filestore or JDBC store.

JMS Topic - A mechanism for delivering messages to multiple subscribers.
JMS Point-to-Point model - Here the sender posts messages to the receiver queue.
JMS Publish/Subscribe Model - Here the message will be posted to multiple subscribers. We use 'topic' rather that 'queue' here.
JMS Server – To host different set of modules and any associated persistent storage that reside on a weblogic server instance. 
lJMS Modules – Contains configuration resources like queues, topics and connection factories 
lConnectionFactory – encapsulates connection configuration information , and enables JMS applications to create a connection 
lJNDI (Java Naming and Directory Interface) – resource lookup of JMS resources like connection factories and destinations (queues or topics) which are configured with a JNDI name. 
lWeblogic persistent storage – To store persistent message data.
     Eg : Filestore or JDBC-accessible. 

Logical diagram

JMS API architecture diagram

How to create a distributed JMS Queue

 I have seen a very good topic for this. Go through the below link

How to create a distributed JMS Queue


Friday, July 8, 2011

Getting Started - XQuery Dev inside OSB Eclipse

  • Should have installed OSB 
  • Basics understanding of middleware technology.
       We can use XQuery/XSL in OSB to do the message transformation. But XQuery is preferred over the XSL because of the  performance advantage. In this post I will show how to develop an xquery using the osb workshop eclipse.

XQuery - Introduction
       XQuery is a light weight language which has got an xml like syntax. XQuery has 3 important parts as below
  1. Namespace declaration
  2. Set of function with their implementations
  3. Declaration of variables
  4. Mentioning the function with which the execution begins.
          For further understanding of the XQuery you can refer

Sample XQuery

Listing-1    xquery version "1.0" encoding "Cp1252";
Listing-2    (:: pragma  parameter="$anyType1" type="xs:anyType" ::)
Listing-3    (:: pragma  type="xs:anyType" ::)
Listing-4    declare namespace xf = "";
Listing-5    declare namespace ns1 = "";
Listing-6    declare namespace ns2 = "";
Listing-8    declare function xf:sample($requestDoc as element(*))
Listing-9                    as element(*)
Listing-10    {
Listing-11                <ns2:Address>
Listing-12                  <ns2:name>
Listing-13                  {
Listing-14                  $requestDoc/ns1:FirstName/text()
Listing-15                  }
Listing-16                  </ns2:name>
Listing-17                  <ns2:phone>
Listing-18                  {
Listing-19                  $requestDoc/ns1:PhoneNumber/text()
Listing-20                  }
Listing-21                  </ns2:phone>
Listing-22                </ns2:Address>
Listing-23    };
Listing-25    declare variable $requestDoc as element(*) external;
Listing-27    xf:sample($requestDoc)


Listing 1 - declaration of xquery
Listing 2 to 3 - comments
Listing 4 to 6 - Namespace declarations
Listing 8 to 9
     This is the code snippet for the function 'sample' which takes 'requestDoc' which is of type element(*),             that is the xml. It returns the type element(*) which is also an xml.

Listing 10 - shows the start of the xquery function
Listing 23 - shows the end of the xquery function
Listing 11 to 22 - the body of the function 'sample'
 Here we are doing the transformation.  What ever we write it in these lines will be the final output of the 
 xquery tranformation
Listing 14 or 19 - Here we are assigning the data obtained from request xml to the output response xml.

Listing 25 - declaring the request variable 'requestDoc' as 'external' as type 'element(*)'. So when we test this xquery from the OSB flow, we will bind the request xml with 'requestDoc' variable and we can transform the request xml to the response xml. 

Listing 27 - This is the last line of the xquery where the execution of the xquery begins. Suppose if we have multiple functions, what ever function is given in the last line of xquery will be the entry point of execution.

Development of XQuery in OSB Workshop - Eclipse
          Open the eclipse and create a project . Right click on the project and create a new xquery

Give some name

Now give the request binding variables.
Here I have added only one variable.
Give the 'Parameter Name' as 'requestDoc'  and click on 'Add' so that we can add the request binding variable.

Similarly mention the response also

Now we have created the xquery. It will be now opened in the osb eclipse editor. The editor has 3 parts.
  1. Design
  2. Source
  3. Test
We can use 'Design' part if we have the source and destination schemas.

Now click on 'Source' and you can see the xquery source code.

Now modify the xquery as below

xquery version "1.0" encoding "Cp1252";
(:: pragma  parameter="$anyType1" type="xs:anyType" ::)
(:: pragma  type="xs:anyType" ::)
declare namespace xf = "";
declare namespace ns1 = "";
declare namespace ns2 = "";
declare function xf:sample($requestDoc as element(*))
    as element(*)
declare variable $requestDoc as element(*) external;

Sample request xml for Testing

<ns1:AddressDetails xmlns:ns1="">

Testing the application

Now Click on the 'Test' tab inside the xquery editor for testing

Now we have successfully created an xquery and tested it. 

 Testing the XQuery inside OSB Message Flow

      Create a new sample osb project. If you are a beginner you can refer the below post

 In the request flow drag one 'replace' node 

     Click on 'XPath' and enter the value as '*'

     In Variable : body
     Now click on 'Expresssion' and click on 'XQuery Resource' and browse to the sample xquery
     and enter $body/* into the 'requestDoc'.

Now you  can deploy the application and test it.

   This topic is intended to give an introduction to Xquery development and using the same inside the osb message flow. You can better explore more.


    please contact Sajeev Ramakrishnan



Saturday, July 2, 2011

OSB Dev using Eclipse - Getting Started

   I hope that you have installed OSB 11g and created domain. Now it is the time to make your hands dirty. I will explain to you how to create a basic http-http flow using eclipse. So why to wait, open your eclipse and go on!!.  


  • Oracle Service Bus Configuration Project - After opening the eclipse create the osb configuration project which hold multiple osb projects.
  • OSB project - holds the actual application which consists of proxy services and business services.
  • Proxy Service - which holds the actual flow implementation. It can perform routing, transformation,sercurity, monitoring and reporting
  • Business Service , which acts as an abstract access layer for the end system component where we configure the interface. Proxy service calls the end system using business service. Business services can be of HTTP, JMS, MQ, File , FTP etc.
Sample Flow (HTTP-HTTP)

Open the Eclipse and create Oracle Service Bus Configuration Project

Right click on the Oracle Service Bus Configuration project and create a new Oracle Service Bus project

Give some proper name

Right click on the Oracle Service Bus project and create new proxy service.

Open the new proxy service and click on the 'Transport' section. Select the protocol as 'http' and give a proper HTTP access URI.

Click on the 'Message Flow' section on the proxy service and drag a 'pipeline pair' to the message flow.

You can see 'Request pipeline' and 'Response pipeline' inside the pipeline pair.

Drag a 'stage' into the Request pipeline. Stage is used just to group different nodes in the flow.

Now Right click on the Oracle Service Bus Project and create a new 'business service'

Open the new business service and click on 'Transport' section . Configure 'http' as protocol and add one proper end system URI. In the figure given below, it is configured as Instead please configure any tomcat stub which gives any xml as the output.

Go back to the proxy service. Drag 'Service call out' to the 'stage'. The service call out is used to initiate a request to the end system with the help of business service and get back the response.

Click on the service call out and then click on the 'Browse' button below and select the business service.

Enter the Request variable as 'body' and response variable as 'response'. You can use any name for the response variable. But for the request variable you should use 'body' as the request xml resides in the 'body' variable.

Drag a 'replace' node to the response pipeline pair and configure it. This will copy the response obtained from the downstream to the body variable so that the response will be returned to the client.

Now the application is ready and it need to be deployed. For that we have to add the server to the workspace. 

Select the appropriate server

Select the domain directory

Finish creating the server and right click on the server created and select 'Add and Remove' and add your Oracle Service Bus Configuration Project to the server.

Right click on the 'Server' and click on 'start'. After some time the server will go to the 'Running' state.

Right click on the server and click on 'publish' so that your application will be deployed .

Testing the application
    Right click on the proxy service and select 'Run As' and select 'Run on Server' . A new window will be opened and paste some xml and hit run. If there are no errors in the end system stub, you will get proper output.

Note : Make sure that your managed server is running before testing the application.

Paste one xml on the 'Payload' section and hit 'Execute'

If your stub is working properly, You can see the proper response.

    This topic is just intended to kick start the development. There are more things ahead. Any way you have taken the first step of OSB application development. Try to explore more in it.


    please contact Sajeev Ramakrishnan