Most of you will say that it is a general-purpose, concurrent, object-oriented, class-based, and runtime environment(JRE) which consists of JVM which is the cornerstone of the Java platform. This blog will clear all your doubts about why to learn java, features, and how it works.
In this blog, I would be covering the following topics:
Java Applications
Before I go ahead with this, let me brief you about why you should choose Java. It is highly popular and has dominated this field from the early 2000s until the present of 2018.
Some of the applications are listed below:
- Banking: To deal with transaction management.
- Retail: Billing applications that you see in a store/restaurant are completely written in Java.
- Information Technology: Java is designed to solve implementation dependencies.
- Android: Applications are either written in Java or use Java API.
- Financial services: It is used in server-side applications.
- Stock market: To write algorithms as to which company they should invest in.
- Big Data: Hadoop MapReduce framework is written using Java.
- Scientific and Research Community: To deal with huge amounts of data.
Wait! Java can do more.
Let’s see how some of the technologies make use of Java as an essential core of their functionalities.
Let’s see how some of the technologies make use of Java as an essential core of their functionalities.
You can see in the above image, Java is an ocean of opportunities.
Let us see a brief history of Java.
History
Java is a programming language developed by James Gosling with other team members named Mike Sheridan and Patrick Naughton also called Green Team in 1995 for Sun Microsystems for digital devices such as set-top boxes, televisions, etc. Now, let us explore the language in detail.
What is Java?
It is an object-oriented language similar to C++, but with advanced and simplified features. This language is free to access and can run on all platforms.
Java is: –
- Concurrent where you can execute many statements instead of sequentially executing it.
- Class-based and an object-oriented programming language.
- The Independent programming language that follows the logic of “Write once, Run anywhere” i.e. the compiled code can run on all platforms which support java.
In simple words, it is a computing platform where you can develop applications.
Features
Simple: Java has made life easier by removing all the complexities such as pointers, operator overloading as you see in C++ or any other programming language.
Portable: This is platform-independent which means that any application written on one platform can be easily ported to another platform.
Object-oriented: Everything is considered to be an “object” which possesses some state, behavior and all the operations are performed using these objects.
Secured: All the code is converted in bytecode after compilation, which is not readable by a human. and java does not use an explicit pointer and run the programs inside the sandbox to prevent any activities from untrusted sources. It enables us to develop virus-free, tamper-free systems/applications.
Dynamic: It has the ability to adapt to an evolving environment that supports dynamic memory allocation due to which memory wastage is reduced and the performance of the application is increased.
Distributed: This language provides a feature that helps to create distributed applications. Using Remote Method Invocation (RMI), a program can invoke a method of another program across a network and get the output. You can access files by calling the methods from any machine on the internet.Next
Robust: Java has a strong memory management system. It helps in eliminating errors as it checks the code during compile and runtime.
High Performance: Java achieves high performance through the use of bytecode which can be easily translated into native machine code. With the use of JIT (Just-In-Time) compilers, it enables high performance.
Interpreted: Java is compiled to bytecodes, which are interpreted by a run-time environment.
Multithreaded: Java supports multiple threads of execution (a.k.a., lightweight processes), including a set of synchronization primitives. This makes programming with threads much easier.
Components
JVM (Java Virtual Machine)
It is an abstract machine. It is a specification that provides a run-time environment in which the bytecode can be executed. It follows three notations:
- Specification: It is a document that describes the implementation of the JVM. It is provided by Sun and other companies.
- Implementation: It is a program that meets the requirements of the JVM specification.
- Runtime Instance: An instance of JVM is created whenever you write command on the command prompt and run the class.
JRE (Java Runtime Environment)
JRE refers to a runtime environment in which a bytecode can be executed. It implements the JVM and provides all the class libraries and other support files that JVM uses at runtime. So JRE is a software package that contains what is required to run a program. Basically, it’s an implementation of the JVM which physically exists.
It is the tool necessary to:-
- Compile
- Document
- Package Java programs.
The JDK completely includes JRE which contains tools for programmers. The Development Kit is provided free of charge. Along with JRE, it includes an interpreter/loader, a compiler (javac), an archiver (jar), a documentation generator, and other tools needed in Java development. In short, it contains JRE + development tools.
