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 */

Information Technology (IT) tools are here to support your business in the global market. Effective communication is key for IT and business experts to collaborate effectively in search of solutions. Consulting, reaching out for help to a third-party, can bridge the gap between your business marketing experts and IT operations experts, especially with the emergence of big data analytics and its implication on the global market. Having the right consultants equipped with business knowledge and data technology expertise can make a difference.

Your marketing organization is probably familiar with digital tools and conducting global research. Its results can uncover the journey customers take to purchase your products or use your services. It can highlight the pain points and frictions that prevent their experiences with you to be delightful and amazing. Armed with this knowledge and beautiful compelling presentations, marketing executives expect that IT operations leaders will translate these insights into actions.

But people in IT operations are too involved in meeting key performance indicators that have nothing to do with the end customers. Meeting requirements of faster and cheaper don't translate very well into customer satisfaction. A classic breakdown in communication is described in a Harvard Business Review article, “A Technique to Bridge the Gap Between Marketing and IT.” The author goes on to describe how a new CIO at a bank found IT to be focused on the internal organization as their customers, rather than the real end customer. Moreover, no one was looking at the incident reports which clearly showed that incidents were increasing. And nobody looked at what these incidents were doing to the bank’s customers. The startling and scary numbers of incidents were caught and addressed and brought down from 1,000 to 600 or (40%) and later to 450 per week.

Surprisingly, these type of seemingly isolated scenarios are still being discovered within organizations presently, sometimes internally, and through third party insights such as consultants.  By engaging consultants to provide a perspective based on what they’ve experienced before, they can often bring new and innovative ideas or possible challenges to the table that an internal processes probably wouldn’t have been able to see on their own.  Often, third party input can help to provide the translation needed to go from marketing research results into actions that IT operations can understand and make sense in their high-performance culture. When companies understand and use this knowledge to reassess how to improve their customer experiences, they work backward from what customers want to achieve significantly higher improvements. 

IT and business management are more and more being asked to move away from their traditional roles, such as IT being the "technology infrastructure gatekeeper", and instead become enablers across the enterprise of effective collaboration, big data consumers, and key players in driving desired business outcomes. Marketing leaders look to technology as a way to facilitate the customer's journey and his positive experience of it, bring more clients, and meet increasingly higher loyalty goals. They rely on IT projects to enable big data-based behavioral targeting anywhere in the global market. This means projects to analyze search engine results, improve website personalization and optimization, and building of mobile applications for a more personal experience. All these are projects that consultants with their communication, consulting and technical expertise are well prepared to help in order to bridge the expectation gap between IT and other business organizations.

In order to meet these 21st-century business challenges, Information Technology organizations have been transitioning from waterfall stage-gate project management approaches to agile development. The stage-gate method applies a step-by-step approach where waiting, reviewing and approving are required before moving to the next step in the project. Agile management emphasizes collaboration, no decision hierarchies, and few people roles for making quick, customer-focused small changes over time to deliver solutions that delight and amaze customers. Agile development has allowed many businesses to respond quickly to changing customer desires and expectations. But moving to continuous delivery is a struggle requiring focused, dedicated teams that are not well suited to the traditional matrix organization where people are resources whose time must be "chopped" into many pieces and shared among many projects. Agile teams meet frequently as often as daily but never waiting more than a week to do so.

Marketing people are externally focused. IT people are internally focused. The first works with customer emotions. The second works to increase efficiency. Big data analytic tools are used by the first and supported by the second. Consultants can be the glue that helps both come together in effective collaborations that deliver positive business outcomes in both global and local markets.

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

The mainstay of a corporation is the data that it possesses. By data, I mean its customer base, information about the use of its products, employee roles and responsibilities, the development and maintenance of its product lines, demographics of supporters and naysayers, financial records, projected sales ... It is in the organization of this data that advancements to the bottom line are often realized i.e. the nuggets of gold are found. Defining what is important, properly cataloging the information, developing a comprehensive protocol to access and update this information and discerning how this data fits into the corporate venacular is basis of this data organization and may be the difference between moving ahead of the competition or being the one to fall behind.

Whenever we attempt to develop an Enterprise Rule Application, we must begin by harvesting the data upon which those rules are built. This is by no means an easy feat as it requires a thorough understanding of the business, industry, the players and their respective roles and the intent of the application. Depending upon the scope of this undertaking, it is almost always safe to say that no one individual is completely knowledgeable to all facets needed to comprise the entire application.

The intial stage of this endeavor is, obviously, to decide upon the intent of the application. This requires knowledge of what is essential, what is an add-on and which of all these requirements/options can be successfully implemented in the allotted period of time. The importance of this stage cannot be stressed enough; if the vision/goal cannot be articulated in a manner that all can understand, the knowledge tap will be opened to become the money drain. Different departments may compete for the same financial resources; management may be jockeying for their day in the sun; consulting corporations, eager to win the bid, may exaggerate their level of competency. These types of endeavors require those special skills of an individual or a team of very competent members to be/have a software architect, subject matter expert and business analyst.

Once the decision has been made and the application development stages have been defined, the next step is to determine which software development tools to employ. For the sake of this article, we will assume that the team has chosen an object oriented language such as Java and a variety of J EE components, a relationsional database and a vendor specific BRMS such as Blaze Advisor. Now, onto the point of this article.