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 */

The World Wide Web is a fun place to connect with old friends, make new ones, and stay involved in social media. It can also be a dangerous place for those who don’t know how to be safe on the web. Children, teenagers, and young adults with Asperger’s syndrome are especially vulnerable to fraud, sexual predators, and other online dangers.

What is Asperger’s Syndrome?

Asperger’s syndrome is a pervasive developmental disorder on the autistic spectrum. Children, teenagers, and adults with this developmental disorder are not sick. They’re brains are wired differently from people who are not on the spectrum. In the autistic community, people who are not on the spectrum are referred to as neurotypical.

The reason Internet dangers are so much more of a risk for people with Asperger’s syndrome is because of the symptoms associated with it. The best way to describe Asperger’s to someone who is not familiar with it is to call it a social learning disability. The parts of the brain responsible for reading facial expressions, body language, and other social cues do not function properly.

Writing Python in Java syntax is possible with a semi-automatic tool. Programming code translation tools pick up about 75% of dynamically typed language. Conversion of Python to a statically typed language like Java requires some manual translation. The modern Java IDE can be used to infer local variable type definitions for each class attribute and local variable.


Translation of Syntax
Both Python and Java are OO imperative languages with sizable syntax constructs. Python is larger, and more competent for functional programming concepts. Using the source translator tool, parsing of the original Python source language will allow for construction of an Abstract Source Tree (AST), followed by conversion of the AST to Java.

Python will parse itself. This capability is exhibited in the ast module, which includes skeleton classes. The latter can be expanded to parse and source each node of an AST. Extension of the ast.NodeVisitor class enables python syntax constructs to be customized using translate.py and parser.py coding structure.

The Concrete Syntax Tree (CST) for Java is based on visit to the AST. Java string templates can be output at AST nodes with visitor.py code. Comment blocks are not retained by the Python ast Parser. Conversion of Python to multi-line string constructs with the translator reduces time to script.


Scripting Python Type Inference in Java
Programmers using Python source know that the language does not contain type information. The fact that Python is a dynamic type language means object type is determined at run time. Python is also not enforced at compile time, as the source is not specified. Runtime type information of an object can be determined by inspecting the __class__.__name__ attribute.

Python’s inspect module is used for constructing profilers and debugging.
Implementation of def traceit (frame, event, arg) method in Python, and connecting it to the interpreter with sys.settrace (traceit) allows for integration of multiple events during application runtime.

Method call events prompt inspect and indexing of runtime type. Inspection of all method arguments can be conducted. By running the application profiler and exercising the code, captured trace files for each source file can be modified with the translator. Generating method syntax can be done with the translator by search and addition of type information. Results in set or returned variables disseminate the dynamic code in static taxonomy.

The final step in the Python to Java scrip integration is to administer unsupported concepts such as value object creation. There is also the task of porting library client code, for reproduction in Java equivalents. Java API stubs can be created to account for Python APIs. Once converted to Java the final clean-up of the script is far easier.

Related:

 What Are The 10 Most Famous Software Programs Written in Python?

Python, a Zen Poem

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
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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?
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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.