Loose Coupling and Message-based Integration WS 2012 ... - IAAS

Task 2.5 – JMS Message Selectors
A message selector allows the JMS consumer to filter undesired, incoming JMS
messages before they are processed. A selector is defined as a boolean
expression combining header fields and properties in a way reminiscent of the
WHERE statement of an SQL query.
Assume the following scenarios:
1. An insurance application uses a message queue to collect complains from
its clients. The application needs to select from the queue all the messages
that are come from chemists and physicists that work for the University of
Stuttgart.
2. A producer wants to receive a message as soon as it is posted to his
queue an order of at least 100 pieces of the article with the inventory
number “SFW374556-02”.
Define for each of the above scenarios a selector and describe which header
fields and properties have to be included in the message.
Task 2.6 – JMS Topics
Define a hierarchy of JMS topics that describes the German stock market. The
topic German stock market should include the indexes (DAX, MDAX, TECDAX,…)
as well as different industrial sectors as (sub-)topics. The companies enlisted in
the stock market can be represented in different sectors, e.g. a company can
publish its messages over the Topic DAX, as well as over a topic “Diversified
industrials”.
In the scope of the JMS Topic hierarchy resulting from above, consider the
following cases:
● BMW wants to publish messages about its stocks. To which (sub-)topics
should those messages be published?
● A customer wants to receive the messages from every company listed in
the DAX index, as well as from Puma (which is listed in MDAX). Which
topics has the customer to subscribe to?
Task 2.7 Chat Application 1
For this task you may use NetBeans IDE 7.0.1 Java EE Bundle (comes already
with GlassFish Server Open Source Edition 3.1.1:
http://netbeans.org/downloads/index.html) or any other tooling of your choice.
Your task is to develop a chat application that run from command-line using JMS
pub/sub API1. In a nutshell, the chat application receives the name of the user
as launch parameter (i.e. as args[] in the method main). After its launch, the
chat application reads the messages given input by the user from command line
(System.in). Each message is terminated by a carriage return (i.e. the message
is not processed by the chat application unless the user presses the “return”
button). The messages are published on a predefined JMS topic. Incoming
messages are pulled by the very same JMS topic, which the chat application
must subscribe. All incoming and outgoing messages should be also displayed on
the console in the form: [name of the originating user]: [message text]
The following hints should help you while developing your chat application:
1 This task is based on the Chapter 2 from the book “Java Message Service” by Richard Monson and
David A. Chappell