Beginner’s Guide To Java

Anurag Lakhera -

Java is a prominent programming language that is class-based, and object-oriented and is made to have minimal dependencies during execution. The language is conventionally preferred by several organizations and institutions for developing web and mobile applications, enterprise software, computing applications, Big Data Analytics, and several other features.

Founded by James Gosling in 1991, it was initially aimed at interactive television creation, which was filtered to a functional programming language in 1996 with a syntax identical to that of C and C++. Java is a swift, secure, and reliable option among major programming languages chosen by companies and individual developers.

Beginner’s Guide to Java- Common Terminology

For those unfamiliar with Java and its concepts, to start, there are some common terms and concepts which can be retained. Java is a language that lets developers write once, and run anywhere (WORA), which means that a created code can be run on all Java-supported platforms without having to recompile. Java Virtual Machine (JVM) runs the Java bytecode.

In other words, JVM is a medium that provides access to portable Java bytecode over various hardware platforms. Another term is the Java Runtime Environment (JRE) which facilitates ample runtime for the program. It is the combination of JVM and the library files included in the language. Java Development Kit (JDK) is the combination of JRE and other tools required to run the program.

What Are The Applications of Java

Java facilitates a variety of applications that are discussed below:

  • Developing Mobile Applications

Java is among the most popular programming languages for the development of mobile applications. Its dynamic nature provides compatibility with software like Kotlin and Android Studio. Java provides the safety of codes from memory leaks and each platform can be used to compile for distinct purposes in Android development.

  • Developing Web-Based Applications

Java can be used to create and develop robust websites and applications with support through JSPs, Servlets, and Struts. Java ensures high productivity and performance through an excellent set of open-source tools and an Integrated Development Environment (IDE). There is also the availability of numerous plugins for development and testing.

  • Enterprise Applications and Software

Java has an immense range of open-source libraries for developing quality enterprise applications and software. It is known to be pretty robust and secure for enterprise-scale applications. Other factors which attract enterprises to use Java for development are simplicity, flexibility, and reusable codes.

  • Scientific Computing Applications

Java is an excellent choice for developing scientific computing applications and mathematical operations. It provides an easy-to-use and portable framework that promotes distributed computing. Java is prominently used in some of the most advanced scientific applications for developing user interfaces.

  • Gaming Applications

Java is a powerful tool that can be used for creating 2D and 3D games of great quality. Java is supported by the jMonkeyEngine which is highly impactful for creating gaming applications.

  • Big Data Analytics

For big data analytics, Java is used in a variety of ETL (extract, transform, load) applications. Java has multiple applications in the field of data science including statistical analysis, data visualization, NLP, import, export, and cleaning of data, etc.

Components of Java: An Extensive Illustration

Java is a language that is Independent of Platforms due to its unique components.  As mentioned above in the terminology section, there are three major components of Java namely, Java Virtual Machine (JVM), Java Runtime Environment (JRE), and Java Development Kit (JDK). Each of these is explained below:

Java Virtual Machine (JVM)

The feature of write once, run anywhere (WORA) is possible for the developers because of JVM, which allows the programs to be run on any hardware. The role of JVM is to convert bytecode into readable machine code and provide the runtime environment for the execution of programs. It is a core element of both JRE and JDK and is also termed an interpreter.

The JVM comprises the following three subsystems:

  1. Classloader, which loads, links, and initializes the class files whenever a program is run on Java. Bootstrap, Extension classloader, and application classloader are three classloaders for Java.
  2. Runtime Data Area, which is for creating storage and memory threads. It includes components like Method Area, Heap Area, Stack Area, PC Registers, and Native Method Stacks.
  3. Execution Engine, which reads and executes the bytecode designated to the Runtime Data Area line by line.

Java Runtime Environment (JRE)

The JRE is responsible for fulfilling the optimum requirements for the execution of a program in Java. JRE is the combination of JVM with the library files (which may be open source). These library files/package classes are required to run the Java program.

The library components include deployment technologies, user-interface toolkits, integration libraries, lang, and util-based libraries, and other base libraries. JRE is a crucial prerequisite for running any Java application.

Java Development Kit (JDK)

JDK is the complete Java package that not only provides the runtime environment but also enables handling multiple extensions in a single block. The JDK can be installed on any platform like Windows, Linux, and macOS.The Java Development Kit includes the JRE and tools like a compiler (which converts the written code into bytecode), archiver, debugger,  document generator, etc. necessary for developing programs.

JDK is platform-dependent, unlike JVM which can run on any platform. The debuggers in JDK allow the Java developers to functionally develop and test programs, and the document generator (JavaDoc) assists in documentation from the source program.

Java Platform Editions

Java has been divided into various editions by its company of origin Oracle (previously known as SUN Microsystems). These editions differ based on distribution and usage in domains like PC, Mobile, or internet apps. Following are the major Java editions:

  • Java Standard Edition (SE)

The Java Standard Edition provides core software development functions for desktop-based CUI and GUI applications, databases, applets, distributed, and XML parsing applications.

  • Java Enterprise Edition (EE)

The Java Enterprise Edition provides the runtime environment for Web applications and Enterprise applications which are required to be highly scalable, multi-tier, and highly secure.

  • Java Micro Edition (ME)

The Java Micro Edition has components favorable for developing programs and applications on smaller devices like mobile phones. The edition is termed micro because of the small embedded program chips.

  • Java Effects (FX)

The Java Effects platform facilitates the development of web applications with unique animations and graphics and uses a light user interface. The applications generated with FX have a modern look and high-class API.

What Is the Object-Oriented Programming (OOP) Concept in Java?

Java is an object-oriented programming language which means that a program is designed using objects and classes. An object is an instance of a class, and class is thus a broader term. Java provides a user-friendly interface due to the OOP concept since the objects can interact with one another to change the data.

The system operates on the below concepts:

  • Encapsulation

This refers to binding or wrapping the data and codes into a single unit. Data refer to the variables and the codes or functionalities refer to methods. All this is encapsulated in a ‘class’. For example, if the class is fruits, then data or objects can be apples, mangoes, or grapes, and the methods could be cut, juice, or freeze.

  • Abstraction

Abstraction refers to the display of only the relevant functionalities and information rather than the internal details. It is picking selected information from a larger pool.

  • Inheritance

The mechanism of inheritance refers to the acquisition of properties and traits by one or more classes from the other.

  • Polymorphism

This refers to performing a single task in multiple ways or defining that one form can have numerous names. The two ways to do so in Java involve overloading and overriding. Overloading refers to various methods in a similar class with the same name but a different signature, whereas overriding deals with 2 methods, both having similar same and signatures.

In a Nutshell

Java is one of the most widely used programming languages for developing web-based applications, enterprise applications, and Internet applications. It is a class-based, general-purpose, object-oriented programming language that provides multiple platforms to work on. It offers great scalability and security and offers ease of programming to developers.

The object-oriented programming concept of Java works on four major principles; Encapsulation, Inheritance, Polymorphism, and Abstraction. Also, the three major components of Java include Jave Virtual Machine (JVM), Java Runtime Environment (JRE), and Java Development Kit (JDK); each of which has a distinct function.

Key Takeaways

When it comes to programming languages, Java is a pioneer and has been known for its presence for a long time. It provides excellent tools and features for developing various desktop and mobile applications with security, scalability, speed, and reliability. The feature of JVM also ensures portability and the program can be run on multiple hardware platforms

For those who are absolute Beginners to Java, it is important to learn a few basic terminologies, most of which have been shared in this blog. The ease of operation and interactive features will surely bind the user in an absorbing learning process.

Java is a general-purpose programming language, just like JavaScript and Python. It is an object-oriented language with a syntax similar to C and C++. Java is a distinct platform that can be accessed through any hardware which has Java Virtual Machine (JVM) installed.

Java is ideal for creating mobile applications (Android) and web-based applications. Other applications of Java include enterprise applications, big data analytics, gaming applications, and scientific computing applications.

The first step to learning Java is to familiarize yourself with the basics and regularly practice coding. Then further skills would involve selecting specific algorithms on Java and reading sources on programs regularly. Another tip is to trace the codes on paper to implement the trial and error method.