This example implements a part of the ELS functionality dealing with linking a number of related messages, a counted correlation pattern, or an aggregator pattern.
Unlike the simple implementation from Example 1, this implementation will correlate a varying number of messages, statically set at design time. Thus the same implementation can be used to correlate 2, 3, 10 or 30 messages, by modifying the value of a single business process attribute. By obtaining the value of the business process attribute, which controls the message count, from the environment or the initial message, one will change the static implementation into a dynamic counted correlation solution.
Correlations are probably the single least understood area of eInsight functionality. The example discussed in the attached document implements one of the “Event Linking and Sequencing” patterns, present in e*Gate 4.5 and eGate SRE, that is alleged to have been lost in ICAN and Java CAPS. In as much as implementing ELS in eInsight 5.1 using correlation requires some development, rather then just configuration, one could argue that it was lost. In as much as implementing ELS in eInsight 5.1 is possible and relatively simple, one could also argue the opposite.
The example discussed in the document, and illustrated with the Java CAPS 5.1.3 project export, implements a part of the ELS functionality dealing with linking a specific number of related messages, a counted correlation pattern, or an aggregator pattern.
By default Java CAPS uses the Java Message Service infrastructure as its underlying messaging layer. Occasionally there is a requirement or a temptation to develop synchronous service, for example invoked as web services or as HTTP Request/Response services, that invoke some back-end component over JMS. In request/response scenarios the response must be delivered by the component which received the request, a JCD or a BP. If the request is passed to the nback-end infrastructure through a JMS Queue or Topic there arises an issue of getting the response back to the same instance of the JCD or a BP that sent the original request. The attached extract, JMS RequestReply, from an early draft of the “Java CAPS Basics – Implementing Common EAI Patterns“, discusses and illustrates how the JMS RequestReply() method of the JMS OTD can be used to implement this kind of functionality.
This note introduces the use of the Java Properties file, some locations where such a file can be put, a method to use a properties file residing in an arbitrary location without hardcoding the location, and the most basic method of access to the properties in the properties file.
This note walks through an example of configuring Java CAPS 5.1 through adding a custom property to system properties. Java collaboration developed in Note 1 is used to retrieve the value of the new property.
Java CAPS 5.1 developer may need to determine a runtime value of one or more system properties to, perhaps, use its vale for runtime flow control. This is the first in a series of notes on the use of Java Properties for controlling runtime behaviour of Java CAPS solutions.
This note walks through an example of configuring Java CAPS 5.1 and developing, and exercising, a Java Collaboration Definition that dumps all system properties to a file and that accesses the values of two specific properties, by name, and dumping them to a file as well.
Java CAPS solutions can selectively retrieve messages from JMS Destinations using static selector expressions, configured in Connectivity Maps. This configuration is performed at design time and is static – to change a selector value requires that the solution is re-built and redeployed.
After almost 2 years the Java CAPS Book I authored with Sebastian Krueger, Brendan Marry, Saurabh Sahai, Peter Vaneris and Andrew Walker, seems like finally seeing the light of day. The tentative print date for the book, “Java CAPS Basics – Implementing Common EAI Patterns”, Part I, is advertised as set at February 2008 at the pre-order page at Amazon.com.
Handling very large messages in a messaging solution may require memory resources many times greater than the size of the largest message to be handled. Frequently the architect has no choice but to consume or produce a very large message, a file containing a batch or related transactions, for example, or a large and complex XML message generated by, or intended for, an external application. Handling such messages poses special challenges.
Java CAPS can assist with Batch eWay support for data streaming when large messages are manifested as files in a file system.
If it is possible to break large messages up into components and process components individually, or collect components and assemble them into a large message. eTL, another of the products in the Java CAPS Suite, can assist in processing large volumes of data. Whilst ETL (Extract, Transfer and Load) is typically associated with one off batch extraction and load of data, Java CAPS’ eTL can be used both standalone and in-stream as part of a larger Java CAPS solution. In this in-stream mode it will be discussed as a possible means of streaming data between a flat file and database table or between
This extract from the soon–to-be-released book, “Java CAPS Basics – Implementing Common EAI Patterns”, discusses the Java CAPS 5.1 Batch eWay streaming facilities, and presents and compares a number of data streaming implementations, including an eTL implementation.
As at release 5.1 Java CAPS supports WS-Security 1.0 (2004) Username Token Profile. Java CAPS eInsight- and Java Collaboration-exposed web services can be configured to require and validate Username/Password credentials before performing their programmed function. Java CAPS eInsight-based and Java Colaboration-based web service consumers can be configured to supply WS-Security 1.0 (2004) Username Token SOAP Header.
Java CAPS 5.1.3_Notes_Using_WS-Security_1.0_Username_Token_Profile.pdf discusses configuration of the Username Token, creation of users, configuration of access to service and testing secured services. It illustrates the discussion with a step-by-step example of implementing, securing and exercising a web service consumer and a web service implementation which use the Username Token infrastructure.
WSDLWSUserAuth.wsdl is the WSDL interface specification document for a service developed in the example.
XSDWSUserAuthString.xsd is the XML Schema Document defining the data structure used as input and output of the example service.