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 */

As much as we love to assume free Wi-Fi is secure, this is far from the truth. Because you are attaching to a service many others are connected to as well, without security measures, your device can be hacked, especially if the network is unencrypted. Because this encryption involves handing out a 26-character hexadecimal key to every individual wanting to use that network, most places opt for ease of access over security. And even with a secure network, your information is vulnerable to everyone else who has the password and is on the network.

This may not seem like such a big deal and many people don’t believe they have anything to hide on their personal devices, but remember what you use on those devices. Chances are your e-mail is attached as well as all other social media sites. You may have apps that track your finances or private messages to certain others that you would never want anyone else to see. Luckily, there are steps that can be taken to reduce and prevent any unwanted information grabbers from accessing your personal information.

To start, go through your computer’s settings in order to verify your operating system’s security functions are all set to offer the highest protection. Open up the Control Panel and double check that your Firewall is enabled for both private and public networks. Then, go to Network and Sharing to open Change advanced sharing settings. In here, you can turn off file and printer sharing and network discovery for public networks.

One of the most important things to watch for is HTTPS. Hypertext Transfer Protocol Secure ensures secure communication across the web. Many of the major email systems use this when you log in (as another layer of password protection) but drop the security as soon as the login is complete. To keep this going, HTTPS Everywhere is a browser extension that gives you a secure connection when browsing some of the more popular sites. It can also be programmed for other sites you like to visit that don’t use HTTPS.

Not every place on the internet provides the choice of HTTPS, and VPNs are there to fill in the security gap. Virtual Private Networks allows data to be sent and received through public access points as if it were directly connected to a secure network. Many businesses offer this for company devices, but if you are an individual looking for that kind of security, ProXPN is a free version that can be upgraded. Unfortunately, it limits your speed, but other choices include VPNBook, OpenVPN Shield Exchange, and OkayFreedom.

With these three steps implemented, secure public Wi-Fi can be achieved. No longer will you have to worry about connecting in an unsure environment with strangers, never knowing if your information is being stolen. With all of the options free of charge, it is also an affordable means of protecting yourself that only takes a little time and effort to implement and guarantee safety.

In Demand IT Skills

Password Management Tools

Net Neutrality for the Layperson

What are a few unique pieces of career advice that nobody ever mentions?

Let’s face it, fad or not, companies are starting to ask themselves how they could possibly use machine learning and AI technologies in their organization. Many are being lured by the promise of profits by discovering winning patterns with algorithms that will enable solid predictions… The reality is that most technology and business professionals do not have sufficient understanding of how machine learning works and where it can be applied.  For a lot of firms, the focus still tends to be on small-scale changes instead of focusing on what really matters…tackling their approach to machine learning.

In the recent Wall Street Journal article, Machine Learning at Scale Remains Elusive for Many Firms, Steven Norton captures interesting comments from the industry’s data science experts. In the article, he quotes panelists from the MIT Digital Economy Conference in NYC, on businesses current practices with AI and machine learning. All agree on the fact that, for all the talk of Machine Learning and AI’s potential in the enterprise, many firms aren’t yet equipped to take advantage of it fully.

Panelist,  Michael Chui, partner at McKinsey Global Institute states that “If a company just mechanically says OK, I’ll automate this little activity here and this little activity there, rather than re-thinking the entire process and how it can be enabled by technology, they usually get very little value out of it. “Few companies have deployed these technologies in a core business process or at scale.”

Panelist, Hilary Mason, general manager at Cloudera Inc., had this to say, “With very few exceptions, every company we work with wants to start with a cost-savings application of automation.” “Most organizations are not set up to do this well.”

JAVA SCRIPT TUTORIAL – THE ESSENTIAL ELEMENTS

If you are looking to increase your proficiency in programming, it can make a lot of sense to invest some time into learning how to use JavaScript, or taking a Java Script tutorial.  It is one of the most popular and powerful options available today for people to use in programming different parts of their websites.  It often finds use in headers, or in interactive features displayed on pages.  It allows you to execute many different functions, such as calculation, pulling data from forms, special graphical effects, customized selections, custom security protocol and password systems, and much more.  Here are some essential points to keep in mind:

·         Java vs. JavaScript – These two languages are not the same.  Java uses completely separate files for their headers and classes, and they need compilation prior to execution.  Java is used in the creation of applets for pages.  JavaScript is much easier and simpler to learn than regular Java, and Java Script tutorials are often significantly more accessible for the average user.

·         OOP – OOP, or object oriented programming, is a specific programming technique that simplifies complicated computer programming conceptual issues.  Essentially, it lets a programmer treat whole chunks of data (defined either by users, or by the system itself), and modify or access them in specific ways.  It does this by classifying different parts of the programming into Objects, Methods, and Properties, which will be discussed more in depth in the future, in other Java Script Tutorials.