Ajit Sagar

This is the third in a series of articles focused on using Java and ColdFusion technologies to develop an Online Ticket Store application. In the July issue of JDJ we went through the ticket reservation system for our online store. We took a look at how the actual protocol used for communicating with the airline back offices could be abstracted at the Service Access tier. This month JDJ is focusing on XML, which brings us to an aspect of our store transactions that we haven't paid much attention to ­ data formatting. Let's pause to think about the type of data we're transporting across the different tiers of our architecture. Primarily, the end user submits his or her search criteria for an airline ticket and gets back a response from the airline back office. During this transaction the data goes through several tiers of a distributed application. Another part of ou... (more)

JT Router: Let Your Clients Tunnel Their Way Across The Internet

Consider an Internet client that wants to connect to a site which allows access only to trusted clients. Consider a trusted client that has access to the site. Wouldn't it be great if the trusted client could relay the Internet client's data to the restricted-access site? In other words, it could act as a "channel", or a "router", for a restricted site. This article describes JTRouter - a multi-threaded Java program that acts as a tunnel for socket communication between an Internet client and a remote server. JTRouter allows a machine to initiate as well as accept Internet conne... (more)

Take a Ride on the InfoBus

Components transcend the programming language and support a very high degree of reuse. They greatly simplify the construction of large and complicated software architectures. One of the main reasons why Java promises such a bright future for the computing world is because of its inherent support for component architectures. Some examples of Java's component support are JavaBeansª, Java Foundation Classes (JFC), JavaBeans Activation Framework (JAF) and the InfoBus. This article introduces the InfoBus, a specification for interconnecting JavaBeans by defining the interfaces and th... (more)

Splitting Tiers

The story about how the n-tier architectures evolved from the single-tier mainframe model has probably been told umpteen times by now (in fact, I retold it myself in last month's e-Java column). Nowadays the trend is to distribute functionality. Modularize everything. Components provide the means to successfully replicate your product in a gazillion scenarios. Client/server is old news. Think distributed architectures. Personalized Webtops. That's the name of the game today. It's easy to get caught up in the hype and lose touch with reality. The Internet fosters a new type of dy... (more)

The Blind Men, the Elephant, and App Server Migration

The six blind men* who attempted to describe the elephant eventually described it only from their perspectives - the parts and not the whole. The same malady can be found lurking in one of the problems that faces many organizations that have adopted J2EE as their platform of choice: the migration of these applications between J2EE application servers - be it vendors or versions. The number of migration initiatives that have come up in the past few years is substantial. There are several reasons for this: Java, as ever, is rapidly evolving. Although the splitting of Java into thre... (more)