Weblog for the AMIS Technology corner
Posts tagged soa
Using the MetaData Services (MDS) in a SOA environment – part 1
Feb 10th
Before I talk about the advantages en methods of using the MDS, I want to introduce myself, because this is my first public post on the AMIS technology blog. My name is Robert van Mölken and I’m 26 years old. I’m now actively working, as a SOA Consultant / Developer, for nearly 5 years. My main toolstack is SOA Suite (3,5 years 10gR3 and 1,5 years 11gR1), but also have experience with opensource BPEL / ESB alternatives from Apache.
In many big SOA application all the composites use the same canonical1 data model (message definitions) for their service contracts. Many entities and elements (complex- and simple types) are reused. Therefor it is not a good choice to use a local copy for the service contracts (WSDLs) and message definition files (XSDs) in each SOA composite project.
If you do so and a mayor (common) part of the message definitions changes then you need to update all the SOA composite projects, where these files are used, with the new version of the files. Oracle created the MDS to solve this issue. MDS stands for MetaData Services. The MDS holds all kind of xml-based files, like WSDLs, XSDs, Domain Values Maps but can also hold fault policies and event definitions (for Event Delivery Network).
Review of Oracle Service Bus 11g Development Cookbook (Packt Publishing) by Edwin Biemond, Guido Schmutz, Eric Elzinga et. al.
Feb 5th
Recently I gained access to an electronic copy of the just released Oracle Service Bus 11g Development Cookbook, written by five authors – all experts on OSB and three personal acquaintances of mine. I was very interested in learning about the final result after hearing many intermediate comments during the writing process as well as reading the occasional remark on Twitter. Knowing Guido, Eric and Edwin and assuming the same expert level for the other two authors, I anticipated a very interesting read.
Below I will share my impressions from browsing through this solid 500+ page volume. Note: the homepage for the book can be found here: http://www.packtpub.com/oracle-service-bus-11g-development-cookbook/book .
Jouw toekomst als Oracle professional – AMIS !!EXTRA!! informatieavond over jouw ontwikkelingspad
Jan 24th
Als je dit leest en je bent Oracle professional – ontwikkelaar of administrator – is de kans groot dat je jouw carriere bent gestart in de jaren ‘90, in het tijdperk van Oracle7, Oracle Forms en Client/Server applicaties – net voor de opkomst van Java, internet, mobiel en SOA. Misschien ligt je start daar nog wel voor en misschien ben je van een tikje later. Maar in elk geval: je hebt een solide fundament en al vele jaren ervaring in Oracle technologie.
Nu is het 2012. En de afgelopen jaren is de technologie in hoog tempo ontwikkeld. Web 2.0 applicaties en multi-tier architecturen dienden zich aan en SOA, Service Bus en BPM zijn opgekomen. Java is overal – en HTML 5 staat op het punt om Flash en Silverlight te verdringen, in desktop browsers en in mobiele devices. Eindgebruikers worden mondiger en veel-eisender en real-time, push-enabled, BI-gedreven dashboards en multi-channel takenlijsten worden in snel itererende agile-projecten gerealiseerd.
Oracle 11g Database doet alle simpele DBA taken zelf – en de uitdaging voor de Database Administrator is verschoven naar groter en interessanter, zeker als 24/7 beschikbaarheid, virtualisatie en de cloud als infrastructuur opduiken. Middleware administratie en integrale security zijn zomaar twee nieuwe uitdagingen op de weg van de administrator, naast een verdergaande consolidatie en professionalisering van deployment en monitoring.
De uitdaging voor de Oracle professional lijkt duidelijk: hoe kies je je weg naar de toekomst? Om interessante klussen te blijven (gaan?) doen is het nodig om aansluiting te vinden bij de ontwikkelingen in de markt. Eerst moet je natuurlijk goed inzicht hebben in wat die ontwikkelingen zijn – in de markt in het algemeen en binnen de Oracle technology stack in het bijzonder. Dan moet je uitvinden hoe je vanuit je huidige kennis en ervaring de aansluiting vindt en jezelf prepareert voor het werken met de huidige en komende technologie. En tenslotte moet je het gaan doen – kennis vergaren, ervaring opdoen en je profileren om de passende klussen op te kunnen pakken.
Business Validation in Oracle SOA Suite 11g using Schematron
Jan 5th
In a previous post I’ve explained the Schematron standard, how it works and how to use it. In the Oracle SOA Suite you can ‘Validate Semantic’ on the input (request) of a routing rule in a Mediator component by selecting a Schematron file. This is the Schemtron xml file in which you define your validation rules. The SOA Suite takes care of applying them on the request by executing the double transformation.
However, to be able to get the Schematron file working you need to declare the namespaces of the input message and rewrite a report rule to an assert rule. In this post I will show you how to do this with the same business rules (so the same Schematron rules and Schematron file) as the last example in a previous blog explaining Schematron.
Read the rest of this entry »
Difficulties with a more complex Business Rule Engine in Oracle SOA Suite
Dec 23rd
In my previous post I’ve shown how to create a composite in the Oracle SOA Suite with a simple decision table in a Business Rule Engine component. For that post I had used quite a simple data model resulting in a small xml/xsd tree. For our project I wanted to repeat the exercise with the real data model, so a larger xml tree defined by multiple imported xsd files. Unfortunately it wasn’t as easy as I hoped for. In this second blog post about the Business Rule Engine I’ll show you about the difficulties I had and how I’ve solved them. Read the rest of this entry »
Cookbook creating Business Rule Engine with a simple Decision Table in Oracle SOA Suite
Dec 13th
For educational purposes I’ve created a cookbook in powerpoint format on how to create a simple decision table in Oracle SOA Suite with a Business Rule engine.
To share this I’ve uploaded it to slideshare and post it here in the Amis blog as well. Read the rest of this entry »
How to call a webservice directly from Java (without webservice library)
Jun 29th
In this blog I will show you how you can call a webservice programmatically in Java without using a webservice library like JAX-WS or Apache Axis. Normally you would use of course a webservice library, but in some cases this can be useful and quick; for example when you have problems generating a client proxy with a webservice library or if you only need some small specific parts of the SOAP response XML tree. It shows that a SOAP call is just XML over HTTP, from a plain piece of Java code. Then, I will show you an example how you can use this and make your own servlet webservice-tester like a simple SoapUI in JDeveloper 11.1.1.3.
Choosing the best way for SOA Suite and Oracle Service Bus to interact with the Oracle Database
Jun 21st
In the past few weeks, I have encountered a similar discussion in various organisations. Each organisation uses either SOA Suite (11g) or Oracle Service Bus (11g) at the core of their SOA infrastructure – either for integration purposes, for workflow and process orchestration or for both. In each organisation, the role of one or more databases is crucial and interaction between the SOA environment and the database is one of the most common and therefore important functions in their enterprise IT environment.
Given the importance, it is only logical that the way(s) chosen for linking the SOA component to the database is carefully selected – and evaluated every now and again. Technology may have progressed, experience may have taught us a lesson or two, the knowledge and skills may have evolved.
Interestingly enough, the number of ways for SOA Suite and OSB to communicate with the database is quite high. This article includes an illustration that shows over 20 different interaction channels that we can choose from with a fairly wild variation of attributes, required skills, productivity and performance characteristics.
Among the choices we face is the question of the communication protocol to use for accessing the database. Roughly speaking, we can go through JDBC (via a JDBC Data Source on the WebLogic Server), via HTTP or using ‘another’ channel such as File System, FTP, Email, XMPP (Chat) etc. The communication protocol may in part determine another choice that awaits us: what will be the format and nature of the messages that we exchange: text based (XML, JSON, CSV) or strongly (Oracle-ly) typed. We know that on the one hand we have the world of XML in the SOA middleware components, and on the other side the relation world of the Oracle database – at least relational and strongly typed at the core.
So when choosing the method for having the SOA components interact with the database, we have to decide on the communication protocol and we have to determine where in the route from table to SOA component (and vv.) the conversion from Relation to XML or from XML to Relational will take place.
Considerations when making that decision include the question who has to do the work of making the XML <=> Relational conversion at design time and at run time – what is the productivity of an approach and what the performance impact. Other considerations include robustness and agility or ability to maintain and evolve the implementation. Of course the required skills factor into this decision as well as the complexity of the architecture, the design, development, test and deployment process and the nature of the interaction: read only, data manipulation, small or large documents, synchronous or asynchronous (or even fire and forget) etc.
Android puts Oracle on the (Google) map.
Mar 24th
For a couple of months I have been discovering the Android platform. As an original Oracle developer I was wondering how an Android app can be connected to an Oracle database.
For this purpose I developed an Android app that stores speed traps that users may hit while driving, into an Oracle database. The app also retrieves these speed traps from the database and draws them onto a Google map:
Fig. 1 After pressing the Android device’s menu button, two menu options ‘Retrieve’ and ‘Report’ (speed traps) appear.
Fig. 2 After pressing the ‘Retrieve’ option all speed traps already stored in the database appear as markers on the map.
Oracle 11g SOA Suite – Service-enable a Query Using the Database Adapter’s Execute Pure SQL Option
Dec 23rd
The Database Adapter is a powerful tool to expose data and PL/SQL code in your service applications. If you want to quickly service-enable a custom-made query, you definitely may want to explore the “Execute Pure SQL” option of the Database Adapter.
This tutorial will show how to service-enable a query step by step using the Database Adapter with Pure SQL.
Business Case: Retrieving Department Information
Assume you have written a query that retrieves information for departments in your database and you want to service-enable this query. The query optionally accepts two arguments: a department ID and a department name. Selection on a part of the department name is possible and selection is case-insensitive. If the arguments are both empty, all departments will be returned by the query.
The query we are talking about here does not only contain columns that are mapped 1-on-1 on database columns but also a concatenation expression and calculated columns using analytical functions. Therefore the “Execute Pure SQL” option of the Database Adapter is a logical choice to expose this custom-made query.
