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 */

Viruses, trojans, and other malicious programs are everywhere. There's always a new threat to your computer's security, and many of these threats invade your computer without you even knowing. Most viruses aren't going to loudly announce themselves, so it's important to know the hidden ways in which your computer can become infected.


Infected Files from Other Computers

Whether you're borrowing someone's flash drive or grabbing a file from their computer, your computer can become infected if the file or device you're using already contains a virus, trojan, or other form of malware.

This is a very common issue, and you won't even know there's a problem most of the time. For example, if your computer is connected to other devices on a network, and you decide to pull an important file off of another computer on the network, your computer will become infected if the file you took has a virus attached to it.

Also, if you forgot your flash drive, and you need to use your friend or coworker's device for the day, then even plugging the device into your computer can cause the infection in the flash drive to be transmitted.


Downloading Legitimate Programs

Another way your computer can be secretly infected is when you download a legitimate program and run it. There are numerous legitimate programs on the internet that can help you in many ways. The programs themselves could be infected, though.

Also, one of the most common ways your computer can become infected is when you don't read the fine print before you download a program. Some of them may insist that you install another small program in addition to the one you initially chose. The boxes that you are supposed to click to give your consent may already be clicked.

This small extra program is the one that may carry an infection that will spread to your computer when you run the main program. You may get a lot of good use out of the legitimate program, but the virus attached to the extra hidden program can cause you a lot of trouble.


Using Vulnerable Applications

Security is a serious matter. If even one of the applications you use on your computer is vulnerable to becoming hacked or infected, then your entire computer is at risk and could become secretly infected. Anything from PDF viewing applications to your operating system can become infected if you don't download the latest security patches and keep everything up-to-date.


Not Using Antivirus Software

Antivirus software can protect your computer from a number of viruses, trojans, and other problems. Your computer can become infected in a number of ways, so you need to have good antivirus software to provide strong protection from hidden attacks.


Viruses, trojans, and other malware can infect your computer in a variety of hidden ways. To prevent infection and problems, you need to be careful about what you download, and you should keep your applications secure. Also, find reliable antivirus software to help.

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I suspect that many of you are familiar with the term "hard coding a value" whereby the age of an individual or their location is written into the condition (or action) of a business rule (in this case) as shown below:

if customer.age > 21 and customer.city == 'denver'

then ...

Such coding practices are perfectly expectable provided that the conditional values, age and city, never change. They become entirely unacceptable if a need for different values could be anticipated. A classic example of where this practice occurred that caused considerable heartache in the IT industry was the Y2K issue where dates were updated using only the last 2 digits of a four digit number because the first 2 digits were hard-coded to 19 i.e. 1998, 1999. All was well provided that the date did not advance to a time beyond the 1900’s since no one could be certain of what would happen when the millennia arrived (2000). A considerably amount of work (albeit boring) and money, approximately $200 billion, went into revising systems by way of software rewrites and computer chip replacements in order to thwart any detrimental outcomes. It is obvious how a simple change or an assumption can have sweeping consequences.

You may wonder what Y2K has to do with Business Rule Management Systems (BRMS). Well, what if we considered rules themselves to be hard-coded. If we were to write 100s of rules in Java, .NET or whatever language that only worked for a given scenario or assumption, would that not constitute hard-coded logic? By hard-coded, we obviously mean compiled. For example, if a credit card company has a variety of bonus campaigns, each with their own unique list of rules that may change within a week’s time, what would be the most effective way of writing software to deal with these responsibilities?

1. The IRS is enabling taxpayers to download their tax transcripts over the internet from the Internal Revenue Service. The official secure URL for the transcripts download followed immediately after The White House fact sheet confirmed the decision. According to the Tech Crunch You Can Now Download Your Tax Returns From The IRS  article, there are some minor bug issues when registering. Given that security has long been problematic with the IRS, the best course of action for the public is to take some precautions when downloading personal information on mobile devices, pc’s and laptops. Installing disk encryption software on all your devices will protect your files reduce risk
2. Have an awesome Start-Up with products in ‘stealth or private beta” that you want like to pitch for a chance to get a table at Disrupt NY? TechCrunch is heading to Atlanta and New Orleans February 18^th and 20^th 2014 and will host a beer fest night in exchange for your thoughts and pitches. Tickets are $5, and all entrepreneurs, investors, dreamers or tech enthusiast are welcome.
3. Cloutex, a cloud computing future enabler has just secured their first round of seed funding.  Cloutex is an Estonian tech startup, which connects and syncs various web applications such as e-marketing, CRM and accounting tools under one convenient hub. The United Partners, SmartCap and EstBan business angels seeded the start-up with $6000, 000.
4. Could you get everything important that you need to know about living successfully from a computer program? Ryan Dube seems to think so. In his 6 Life Habits That Programming Could Teach You Today  he speaks in flow charts, loops and program modules, in the same breath as paying off debt or buying a house.  How can your programming skills help in life skills by modeling some of the same principles?
5. 10 Incredibly Simple Things You Can Do To Protect Your PrivacyPassword protect your devices.  Put alerts on your name in Google; simple tasks that can be significant in protecting your privacy.
6. Adobe Brings 3D Printing Support to PhotoshopAmong the latest updates in Adobe, Photoshop users have the ability to design 3D models from scratch as well as being able to toy around with color, shape and angles.