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 */

Computers. They’re a part of our everyday lives. Most of us couldn’t imagine living a day without them. We use them for school, work, and fun and use them to stay connected to those we love and care about. Since the invention of the web cam, millions of us use webcams to communicate with loved-ones and business contacts far away.

Web camera use has leveled the playing field for business entrepreneurs and given teenagers a fun way to chat with friends. However, solid citizens aren’t the only ones who make use of this popular modern technology. Recently, there have been reports of criminals using a type of webcam spy hack to insert themselves unseen into the living rooms and bedrooms of millions of unsuspecting users.

The Webcam Spy Hack

The most popular way criminals gain access to your webcam is through innocent-looking emails. You may receive an e-card from someone in your contacts list. When you click on it, you’re directed to another website to view the e-card. While you’re listening to music and watching animated puppies scroll across the screen, a Trojan horse is silently installed into your computer’s hard drive.

Passbook is one of the newest features of the iPhone. What many people were offput by standards today is that we rely too much on disposable tickets, and the like, such as when you go to the airport for a boarding pass, or a movie ticket. Apple strove to solve that with a new application that is bundled with the newest update: Passbook.

Passbook offers everything you need, especially when a ticket, coupon, or gift card is needed. When you first open the application you are greeted by a sampling of applications that support Passbook, and its features. To begin, install the particular application you want to use. For example, we will be going with the Starbucks application to satiate our coffee needs every morning, as we have a gift card to spend.

Open up the freshly downloaded application, and get ready to be blown away. Like most applications, especially when it has to do with airlines, or coffee, you are almost always required to sign up for a respective account. Don’t worry, it is easy. All you will be asked is to fill out your email, a password, and other miscellaneous information to identify you when you lose your password or others.

Once you have finished signing up, you’re ready to roll. It will prompt you to enter a gift card that you already own, or begin a digital gift card. If you don’t have a gift card, you can start a digital gift card (or, as many may call it: a prepaid card), and pay for your coffee in a fast, and efficient way. Just tap on “Tap to Pay” when you are ready to pay, and tap again after you have paid. It’s really that easy.

The RSS feed, which commonly stands for Really Simple Syndication, is an internet protocol that helps spread the availability of frequently published or updated Internet content.

RSS Benefits for an Internet Content Provider or Blogger
The use of an RSS feed saves immeasurable time for a content provider. When an interested person subscribes to an RSS feed, the owner of that feed now has a way to reach large numbers of people without having to resort to spamming techniques. The RSS feed also allows a content provider to send the requested topical information without specifically asking, every time, to those people who have subscribed. The content provider uses a program, written in XML code to make the information they post available to each person that has requested a subscription to that particular RSS feed.

RSS Benefits for the Average Internet User
The Internet grows larger by the minute. It is easy for a person to have information overload. The use of an RSS feed gives an individual more control over what information they see while on the Internet. It is also very useful for anyone that wants to stay up to date. Subscribing to the RSS feed for a topic of interest automatically provides the subscriber continued availability of the latest information on that topic. The Internet user relies on a small program called an RSS Feeder to gather the information on the RSS feeds to which they have subscribed.

Most browsers these days have built in RSS readers making that gathering the desired information easier than ever to accomplish. Joining an RSS feed is a very simple thing to accomplish.
 

RSS Benefits for Small Businesses

More and more Small Business owners are adapting targeted online marketing campaigns such as RSS Feeds in order to provide relevant content to new and existing customers. Maintaining web content such as:  company news; contests; promotional events; related articles; notifications; product launches; directories; and newsletters are examples of ways of staying in touch with customers in any niche market.  As search engines retrieve information from RSS Feeds and content is syndicated to other websites, chances of increased traffic are inevitable.  For active websites, RSS feeds are invaluable tools for small business owners.

USA.gov Updates: News and Features

Search for RSS feeds (search topics)

Welcome to Google Reader (find and keep track of interesting stuff on the web.)

NPR public radio station (popular, news, program and topics RSS feeds)

RSS in Plain English (video)

10 Helpful Uses of RSS Feeds for Marketing

Incorporate Google RSS feeds onto your site

Adding RSS Content on Yahoo