Java is related to C ++, which is a direct descendant of C. Most Java character is inherited from both these languages. Java gets its syntax from C. Mostly Java’s Object-focused features have been influenced by C ++. In fact, many definitions of Java features come from predecessors, i.e. C and C++. Moreover, the creation of Java was focused on the refinement process in computer programming languages a few decades ago. As you will see, development in each language was driven by the need to solve an important problem that previous languages could not resolve. Java is no exception.
Java was born by James Gosling, Patrick Naughton at Sun Microsystems, Inc. in 1991. It took 18 months to improve the initial performance. The language was originally called “Oak,” but it was renamed “Java” in 1995.
This article covers major topics and aspects of java as a programming language. We will cover topics like What is Java exactly? Why do we use it? What career options Java has in the future? How does it work? What are its features? And many other Java related things
Java is a general-purpose, class-based programming language, focused on something designed to be subject to minimal use. It is a computing platform for application development. Java is fast, secure, and reliable, therefore. It is widely used to develop Java applications on laptops, data centers, game consoles, science supercomputers, cell phones, etc.
There are many applications and even some websites will not work unless you install Java. Java.com, this website, is intended for users who need Java in their desktop applications – especially applications that run Java 8. Developers and users who would like to learn how to set up Java should visit the dev.java website and business users should visit oracle.com/java for more information.
Java Applets run on a Java Virtual Machine (JVM) web browser, which translates Java bytecode into native processing instructions and allows an indirect OS or platform application implementation. JVM provides most of the components needed to use bytecode, which are usually smaller than usable programs written in other programming languages. Bytecode cannot work if the system does not have the required JVM.
Features of Java
Java is an easy to learn programming language for the programmers. Java is chosen as the first programming language by many programmers these days. Moreover, the popularity of Java still persists in the industry. Most of the government, healthcare, defence, education sector websites, and applications are still using Java technologies. It makes Java worth learning and using. If you see Java as a career option then also it can take you to various career paths. Almost everything can be done using Java.
Now, getting on the features of Java, that makes it worthy.
- Platform independent
- Architecture neutral
- High Performance
Java is a simple programming language and easy to understand because it does not have complexities like the other programming languages. In fact, simplicity was the design aim of Javasoft developer peoples, because it dealt on electronic devices where less memory/resources are available. Java has the same syntax as in C, C++, so the programmers who are switching to Java does not face any problem in terms of syntax. Secondly, the concept of pointers have been entirely removed from Java which as it leads to confusion for a programmer and pointers are also vulnerable to security.
Java is an Object Oriented Programming Language, which means in Java everything is written in terms of classes and objects. So, what is an Object? Object is just a real world entity that can represent any person, place, or thing and can be distinguished from others. Every object around us has some state or behavior that is associated with it. For example, a phone, it is a real world entity and has states like color, model, brand, camera quality, etc, and these properties are represented by variables. Also phones are associated with actions like, calling, messaging, photography, etc. and these actions are considered as methods in Java.
The main concepts of any Object Oriented Programming language are given below:
1. Class and Object
Object : An real-life entity that has state and behaviour is known as an object e.g., chair, bike, marker, pen, table, car, etc. It can be physical(tangible) or logical(intangible).
Class : A class is a group of objects which have common properties. It is a template or blueprint from which objects are created. It is a logical entity. It can’t be physical.
Encapsulation in Java is a process of wrapping data code and methods that operate on the data together into a single unit, for example, like a capsule that has several different medicines within it .
We can develop a fully encapsulated class in Java by making all the data members of the class private. And use setter and getter methods to set and get the data in it.
The Java Bean class is the example of a fully encapsulated class.
Abstraction is a process of hiding the implementation details and showing only functionality to the user. In other words, abstraction is hiding of unwanted data from the user and showing only relevant details.
Inheritance in Java is a process in which one object acquires all the properties and behaviours of a parent object. It is an important part of the Object Oriented programming system.
The intention behind inheritance in Java is that you can create new classes that are built upon existing classes. When a class is inherited from an existing class, you can reuse methods and fields of the parent class. Moreover, you can add new methods and fields in your current class also.
Inheritance represents the IS-A relationship which is also known as a parent-child relationship. For Example: Ford is a car.
Polymorphism in Java is a concept by which we can perform a single action in different ways. Polymorphism is derived from 2 Greek words: poly and morphs. The word “poly” means many and “morphs” means forms. So polymorphism means many forms. Let me make it a bit clear for you by giving you an example: a water can mould itself into ice or gas but is a water afterall.
There are two types of polymorphism in Java: compile-time polymorphism and runtime polymorphism. We can perform polymorphism in java by method overloading and method overriding.
If you overload a static method in Java, it is an example of compile time polymorphism. Here, we will focus on runtime polymorphism in java.
The features like WORA (Write Once Run Anywhere) concept and platform independent makes Java portable. Now using the Java programming language, developers can yield the same result on any machine, by writing code only once. The reason behind its execution is JVM and bytecode. Suppose you wrote any code in Java, then that code is first converted to equivalent bytecode which is only readable by JVM. We have different versions of JVM for different platforms. Windows machines have their own version of JVM, linux has its own and macOS has its own version of JVM. So if you distribute your bytecode to any machine, the JVM of that machine would translate the bytecode into respective machine code. In this way portability lets the programmers focus on development and productivity rather than writing different code for different platforms.
Java is platform independent because it is different from other languages like C, C++, etc. which are compiled into platform specific machines while Java is a write once, run anywhere language. A platform is the hardware or software environment in which a program runs.
In Java, Java source code is compiled to bytecode and this bytecode is not bound to any platform. In Fact, this bytecode is only understandable by the Java Virtual Machine which is installed in our system. What I meant to say is that every operating system has its own version of JVM, which is capable of reading and converting bytecode to an equivalent machine native language. This reduces the overhead of programmers writing system specific code. Now programmers write programs only once, compile it, to generate the bytecode and then export it anywhere.
There are two types of platforms: software-based and hardware-based. Java provides a software-based platform.
The Java platform differs from most other platforms in the sense that it is a software-based platform that runs on top of other hardware-based platforms. It has two components:
- Runtime Environment
- API(Application Programming Interface)
Security is a major concern for every application. As every device is connected to each other using the internet nowadays which opens up the possibility to hack a device. And our application build using java also needs some sort of security. So Java also provides security features to the programmers. Security problems like virus threat, tampering, eavesdropping, impersonation can be handled or minimised using Java. Encryption and Decryption features to secure your data from tampering over the internet. An Impersonation is an act of pretending to be another person on the internet. The solution to the impersonation problem is a digital signature, a file that contains personal identification information in an unreadable format.
The Java programming language is robust, which means that it can handle unexpected programming interruptions. There are 2 reasons behind this, first of all, it has a very important and useful feature called Alternative Management. If the exception occurs in the java code then no damage will occur while, in some low-level languages, the system will crash. Another reason Java is so strong is its memory system. Unlike other low-level languages, Java provides JVM-enabled garbage collection time, which collects all unused variables. Garbage collector is a special program under JVM that operates periodically and identifies any unused variables and objects and removes them from memory to free up space. But in the case of some previous languages, there is no such system for memory management, editors are responsible for allocating and distributing memory spaces, otherwise, the system may crash due to insufficient memory.
Java is architecture neutral in format because there are no usage-dependent features, for example, the older version size has been adjusted.
Java compiler produces an architecture-neutral object file format, which makes integrated code work on most processors, with the presence of a Java runtime system.
In C programming, the int data type takes 2 bytes of 32-bit architecture memory and 4 bytes of 64-bit architecture memory. However, it takes 4 bytes of memory in both 32 and 64-bit formats in Java.
Java byte code is translated on the fly to native machine instructions and is not stored anywhere. The development process is more rapid and analytical since the linking is an incremental and light-weight process.
In programming languages, you have learned that they use either the compiler or interpreter, but Java programming language uses both a compiler and interpreter. Java programs are compiled to generate bytecode files then JVM interprets the bytecode file during execution. Along with this JVM also uses a JIT compiler (it increases the speed of execution).
Through the use of Just-In-Time connectors, Java enables high performance. The Just-In-Time (JIT) compiler is an integral part of JRE i.e. Java Runtime Environment, which is responsible for the full implementation of java-based applications during operation. Compiler is one of the key factors in determining application performance on both sides i.e. end user and program developer.
Java is faster than other traditional programming languages because Java bytecode is “closer” to the native code. It is still slower than a combined language (e.g., C ++). Java is a translated language which is why it is slower than integrated languages, e.g., C, C ++, etc.
Thread is a lightweight and independent subprocess of a running program (i.e, process) that shares resources. And when multiple threads run simultaneously is called multi-threading. In many applications, you have seen multiple tasks running simultaneously, for example, Google Docs where while typing text, the spell check and autocorrect task are running.
Server also uses multithreading to provide its services to multiple client requests. In Java, you can create threads in two ways, either by implementing the Runnable interface or by extending the Thread class.
Java is designed for the distributed environment of the internet.
Java is distributed because it facilitates users to create distributed applications in Java. RMI and EJB are used for creating distributed applications. This feature of Java makes us able to access files by calling the methods from any machine on the internet.
Java is considered to be more dynamic than C or C++ since it is designed to adapt to an evolving environment. Java programs can carry an extensive amount of run-time information that can be used to verify and resolve accesses to objects at run-time.
Java is a dynamic language. It supports the dynamic loading of classes. It means classes are loaded on demand. It also supports functions from its native languages, i.e., C and C++.
Java supports dynamic compilation and automatic memory management (garbage collection).
A Java programmer writes a program in human readable language called Source Code. Therefore, CPUs or Chips never understand source code written in any programming language.
These computers or chips understand only one thing, called machine language or code. These machine codes apply to CPU level. Therefore, there will be different machine codes for other CPU models.
However, you need to worry about machine code, as editing is about source code. The machine understands this source code and translates it into understandable machine code, which is a usable code.
All of these operations take place within the 3 components of the following Java platform:
JDK is a software development platform used to create Java applications and applications. The complete JDK form is the Java Development Kit. Java developers can use it on Windows, macOS, Solaris, and Linux. JDK helps them encrypt and run Java applications. It is possible to install more than one JDK version on the same computer.
Here are the main reasons for using JDK:
- JDK contains the tools needed to write Java and JRE programs to execute them.
- Includes launcher, Java program launcher, Appletviewer, etc.
- Compiler converts Java-based code into byte code.
- The Java app launcher opens the JRE, loads the required section, and executes its main path.
Java Virtual Machine (JVM) is an engine that provides real-time location to drive Java Code or applications. Converts Java bytecode into machine language. JVM is part of the Java Run Environment (JRE). In some programming languages, the producer generates a machine code for a particular system. However, a Java compiler generates a Virtual Machine code known as a Java Virtual Machine.
Here are some important reasons to use JVM:
- JVM provides a standalone platform for using Java source code.
- It has many libraries, tools, and frameworks.
- Once you have started the Java program, you can start in any forum and save a lot of time.
- JVM comes with a JIT (Just-in-Time) compiler that converts Java source code into standard machine language. Therefore, it works faster than a standard application.
JRE is a piece of software designed to use other software. Contains class libraries, uploader class, and JVM. In simple words, if you want to run a Java application, you need JRE. If you are not an editor, you do not need to install JDK, but just JRE to run Java applications.
Here are the main reasons for using JRE:
- JRE contains class libraries, JVM, and other supporting files. It does not include any Java development tool like debugger, compiler, etc.
- Uses important package classes such as math, swing, util, lang, awt, and work time libraries.
- If you must use Java applets, JRE should be included in your system
Uses of Java
Java has been known for versatility for a long time and that is the reason why java is still used by many programmers. Below is a list of fields where it is used :
1. Web-Based Applications
It is also used for developing web-based applications because it provides vast support for web development through Servlet, JSP, and Struts. It is the reason that Java is also known as a server-side programming language. Using these technologies, we can develop a variety of applications. The most popular frameworks are Spring, Hibernate, Spring Boot, used for developing web-based applications. LinkedIn, AliExpress, web.archive.org, IRCTC, etc. are the popular websites that are written using Java programming language.
2. Game Development
Java is widely used by game development companies because it has the support of the open-source most powerful 3D engine. The engine provides unparalleled capacity when it comes to the context of the designing of 3D games. The most popular games developed in Java are Minecraft, Mission Impossible III, etc. There are some popular Frameworks and Libraries available for Game Development, like – LibGDX and OpenGL.
3. Mobile Application Development
Java programming language can be considered as the official language for mobile application development. Most android apps are built using Java. IDE Android Studio’s most popular android application development uses Java to improve android apps. So, once you are familiar with Java, it will be much easier to develop android apps. The most popular android apps Spotify and Twitter are made using Java.
4. Distributed Applications
The JINI (Java Intelligent Networking Infrastructure) provides the infrastructure to register and find distributed services based on its specification. It implements a mechanism that is known as JavaSpaces. It supports the distribution, persistence, and migration of objects in a network.
5. Cloud-Based Applications
Cloud computing means on-demand delivery of IT resources via the internet with pay-as-you-go pricing. It provides a solution for IT infrastructure at a low cost. Java provides you with features that can help you build applications meaning that it can be used in the SaaS, IaaS and PaaS development. It can serve the companies to build their applications remotely or help companies share data with others, whatever the requirement.
6. Big Data Technologies
Java is the reason why the leading Big Data technologies like Hadoop have become a reality and also the most powerful programming languages like Scala are existing. It is crystal clear that Java is the backbone when it comes to developing Big Data using Java.
7. IoT Application
IoT is a technology that connects the devices in its network and communicates with them. IoT has found almost all the small devices such as health gears, smartphones, wearables, smart lighting, TVs, etc. For developing the IoT application there is a lot of programming languages that can be used but Java offers an edge to developers that is unparalleled. IoT programmers gravitate towards Java because of its security, flexibility, and versatility.
8. Enterprise Application
Java is the first choice for most software application developers and Java Enterprise Edition (Java EE) is the most popular platform that provides the API and workspace space. It also includes network applications and web services. JavaEE is also considered to be the backbone of various bank applications with Java-enabled UI to retrieve server end.
In comparison to other programming languages, Java stands alone for its security and functionality. Java isolates itself from other programming languages because of functionality and security and it is relevant too. There are some other reasons to use Java are as follows:
Scalability adds capacity to our system. It improves the capacity of the system by adding the system resources without affecting the deployment architecture. We can achieve scalability by increasing the resources such as RAM and CPU in a single system. It is important because it handles the workload, increases the system performance, and maximizes productivity.
Cross-platform means a compiled Java program can be run on all the platforms. Remember that the system must have JVM. After compiling a Java program, the Java code gets converted into the bytecode which is platform-independent. This bytecode is understood by the JVM. We can run this bytecode on any platform.
Java provides its own mechanism for managing the memory known as garbage collection. We need not to care about memory and are not required to implement it to manage the memory. It automatically deletes the objects when they are no longer used by the application. It improves the speed of the application.
Thread is a light-weight subprocess. Multi-threading in Java allows concurrent execution of two or more threads simultaneously. It maximises the utilisation of the CPU.
This article is all about the Java programming language. This article has every basic thing that you need to know about java. Java is a general-purpose, class-based programming language, focused on something designed to be subject to minimal use. It is a computing platform for application development. Java is fast, secure, and reliable, therefore. It is widely used to develop Java applications on laptops, data centres, game consoles, science supercomputers, cell phones, etc.
This article covers all the features and the reason why it is used and so popular among other programming languages. The reason being Java is an easy to learn programming language for the programmers. Java is chosen as the first programming language by many programmers these days due to its features like, it is Simple, supports Object-Oriented concept, it is Portable, it is Platform independent, it assures that the program is Secured, it is Robust, it has a feature of Architecture neutral, it uses Interpreter, it is High in Performance, it uses Multithread, it can be Distributed, and finally last but not the least it is Dynamic.
With all these features Java needs to be really efficient in all ways. And for this, java has its 3 components that help it work at its best. Those 3 components are : JDK, JVM, JRE. JDK stands for Java Development Kit with the help of which you can execute any Java program easily as it has all the tools available for the same. JVM stands for Java Virtual Machine with Java Virtual Machine you can run or compile java on any platform. And JRE stands for Java Runtime Environment, it consists of all the java libraries, JVM, and java supporting files.
It also covers different fields where it is popularly used, like game development, IoT, and many more.