As part of our Java Tutorials program, we will list a number of interview questions to aid in a better understaing of Java and J2EE and, hopefully, provide a greater likelihood of getting a job.  Let us begin with the basics:

1. What is meant by J2EE?

J2EE is an abreviation for Java 2 Platform Enterprise Edition

2.  What is the purpose of J2EE?

The purpose of J2EE is to provide a component based platform in a multitier application model with transaction management, web services and reusable component support.

3.  What is the tier structure of the typical J2EE application?

A typical J2EE application consists of the following tiers/machines:  the client machine (browser/non-browser application), the J2EE server (an application server such as Oracle, JBoss, GlassFish, Tomcat) and a database.

The importance of variables in any programming language can’t be emphasised enough. Even if you are a novice, the chances are good that you will have been using variables for quite a while now.

They are the cornerstone of any language and without them we would not be able to accomplish much of anything. However, most of you up until this point have probably only been working with standard variables, variables which can hold single values such as an integer, a single character, or a string of text.

In this tutorial we are going to take a look at a more special type of variable called an array. Arrays can seem quite daunting at first glance but once you get used to working with them you will wonder how you ever managed to program without them.

The reason arrays are special is because they can hold more than one value. Think about this: say you create a variable which contains a line of text like the code below:

I will begin our blog on Java Tutorial with an incredibly important aspect of java development:  memory management.  The importance of this topic should not be minimized as an application's performance and footprint size are at stake.

From the outset, the Java Virtual Machine (JVM) manages memory via a mechanism known as Garbage Collection (GC).  The Garbage collector

• Manages the heap memory.   All obects are stored on the heap; therefore, all objects are managed.  The keyword, new, allocates the requisite memory to instantiate an object and places the newly allocated memory on the heap.  This object is marked as live until it is no longer being reference.
• Deallocates or reclaims those objects that are no longer being referened. 
• Traditionally, employs a Mark and Sweep algorithm.  In the mark phase, the collector identifies which objects are still alive.  The sweep phase identifies objects that are no longer alive.
• Deallocates the memory of objects that are not marked as live.
• Is automatically run by the JVM and not explicitely called by the Java developer.  Unlike languages such as C++, the Java developer has no explict control over memory management.
• Does not manage the stack.  Local primitive types and local object references are not managed by the GC.

So if the Java developer has no control over memory management, why even worry about the GC?  It turns out that memory management is an integral part of an application's performance, all things being equal.  The more memory that is required for the application to run, the greater the likelihood that computational efficiency suffers. To that end, the developer has to take into account the amount of memory being allocated when writing code.  This translates into the amount of heap memory being consumed.

Memory is split into two types:  stack and heap.  Stack memory is memory set aside for a thread of execution e.g. a function.  When a function is called, a block of memory is reserved for those variables local to the function, provided that they are either a type of Java primitive or an object reference.  Upon runtime completion of the function call, the reserved memory block is now available for the next thread of execution.  Heap memory, on the otherhand, is dynamically allocated.  That is, there is no set pattern for allocating or deallocating this memory.  Therefore, keeping track or managing this type of memory is a complicated process. In Java, such memory is allocated when instantiating an object:

String s = new String();  // new operator being employed
String m = "A String";    /* object instantiated by the JVM and then being set to a value.  The JVM
calls the new operator */

IT Outsourcing came to foray as a means for corporations to focus on critical business operations while having a specialized IT company take over the responsibility of managing the IT infrastructure and application development. For corporations especially in the developed countries, IT outsourcing provided two fold advantages, one was access to a highly talented pool of engineers and that too at a lower cost since countries like India were quickly growing their stature as an IT outsourcing hub.

IT Outsourcing is now as mainstream as ever and almost every leading organization outsources some or all parts of its IT infrastructure to a specialized company. It makes pure business sense and with tightening budget controls, IT outsourcing has become one of the strategic cost reduction driver for most organizations. Moreover, IT outsourcing is no more restricted to companies in USA & Europe outsourcing their IT projects to countries like India. Domestic companies within India itself actively use IT outsourcing including the Indian government like the India Post project given to TCS.

Is it then a no brainer that IT Outsourcing is critical to your business? Well, if it is cheaper and does not seem to have any inherent disadvantages why not!! Not really, IT Outsourcing despite proven benefits has its limitations and you should be cognizant be of the same before considering outsourcing your IT operations.

·         Limitations in estimating the actual cost of IT outsourcing:Let’s tackle the biggest driver of IT Outsourcing-Cost Savings. For anyone to estimate the cost savings from IT Outsourcing one needs to be able to predict the cost of outsourcing which then helps understand the cost savings from the same. Yes, at a higher level it is a matter of a simple $ per man-hour costs and IT outsourcing will appear to be cheaper in almost all cases. However, “hidden costs” are commonplace with IT outsourcing and it can be immensely difficult to accurately predict these hidden costs. For example, you need to be able to identify the costs of transitioning your in-house IT to an outsourcer, management overhead needed to manage the outsourcing relationship etc. In addition, IT outsourcing contracts are fixed at the start of the contract and as a result any additional requirement/change tends to be charged additionally. It is no surprise that IT requirements can change frequently and if your outsourcing contract doesn’t account for flexibility, you might be limited in the actual cost savings you might make. There is no surprise that there have been so many instances of IT outsourcing projects overshooting their budgets by a huge margin such as the one government shared services project going 500 million pounds over budget