What is Java?
Java is an object-oriented programming language. It was originally designed by James Gosling and Bill Joy at Sun Microsystems in 1995. It is now maintained by Oracle.
Java is the language of the Java Virtual Machine. It is used to develop applications that run on a virtual machine. It can be used to develop any kind of application: Web applications, desktop applications, game applications, etc. It is cross-platform, meaning that it can be used on any operating system. Java is compiled into bytecode before it is executed by a virtual machine.
 |
| Introduction to java (image source-freepik.com) |
The goal of the Java language is to enable software developers to create applications that run on any platform and run in any environment, with no modification. The Java Virtual Machine, or JVM, allows Java code to run on any platform and any operating system. The JVM is also a language that can be used to develop applications.
Java's syntax is similar to C++, which means that Java is easy to learn for C++ programmers.
{tocify} $title={Table of Contents}
History of Java
The history of Java is long and complex. Java was first developed in 1995 by James Gosling and Bill Joy at Sun Microsystems. It was designed to run on Sun's own Java platform, called the Java Virtual Machine. Java was originally designed to run only on the Sun platform. In 1997, the Java Community Process (JCP) was created to develop a specification for Java. In 1998, Java was made open-source. By the end of 1998, Java was already being used by the public.
In 1999, the first version of Java was released: Java 2 Standard Edition (J2SE).
In the 2000s, Java became a multi-platform programming language. In 2001, Java 2 Micro Edition (J2ME) was released. This version of Java was designed to run on mobile devices. In 2003, Java 1.4 was released.
In 2005, Java 1.5 was released. Java 1.5 was a huge step forward in the language's history. Java 1.5 was backwards compatible, which meant that existing programs could continue to work. Java 1.5 was the first version of Java that supported the single-threaded model of programming.
In 2006, Java 1.6 was released. Java 1.6 was a new version of Java that had many improvements. The most notable of these improvements were thread safety and type safety. The Java 1.6 version of the JVM had better garbage collection, and the compiler produced more efficient code. Java 1.6 was also the first version of Java that supported the classpath.
Java 1.7 was released in 2009. Java 1.7 was a major update to Java. It included many new features and enhancements. Java 1.7 introduced lambda expressions, enums, and many other new features.
The Java language has been used in a number of different fields. For example, it has been used in gaming, education, finance, and the development of mobile devices. Java has been used in the development of many games. Some of the most popular games in the world are based on Java.
Java is one of the most popular languages. In 2012, there were more than 2 billion downloads of Java
What is Java Platform?
Java Platform is a collection of Java Virtual Machines, tools, libraries, documentation, and other resources that enable software developers to create Java applications.
The Java Platform consists of the following:
The Java Virtual Machine (JVM)
The Java Runtime Environment (JRE)
The Java Development Kit (JDK)
Java language specification
The Java platform provides a means for software developers to write applications that run on a virtual machine. A virtual machine is a software program that interprets a compiled application. The virtual machine acts as a host to the application. It can be used on any operating system.
What is Java used for?
Java is used to create many different kinds of applications. The applications can be desktop applications, web applications, or games.
A desktop application is a software application that runs on a desktop computer. These applications can be used to do anything, such as create spreadsheets, word processors, games, etc.
A web application is a software application that runs on a web server. The web server can be a public server or a private server. The application can be hosted by a web server, which is connected to the Internet. The web server is typically the computer that is connected to the Internet. The application can be used to create websites, search engines, shopping carts, etc.
Java Features
The Java language is powerful. It has a number of features that make it a good language to use.
- The most important feature of Java is that it is object-oriented. Object-oriented programming means that programs are made up of objects. Objects are used to store information and instructions. An object has a type. It is possible to create multiple objects of the same type.
- Another feature of Java is that it is compiled. This means that it can be turned into machine language and run on a computer.
- Java is also interpreted. This means that the Java language is used to write the instructions that are run by the computer.
- Java is also dynamically typed. This means that it can be used to write programs that have variables that can have different types. This is useful for making programs that can be flexible.
- Java is a compiled language. This means that the Java language is turned into machine language before it is run.
- The Java language has a syntax that is easy to learn. It also has a lot of built-in features that make it easy to write programs.
Components Of Java
A Java application is made up of many different parts. The different parts of a Java application are called components. The following components are typically included in a Java application:
Java code:
This is the code that is written in the Java language. The Java code is usually stored in the source files of the application.
Class files:
These are the compiled version of the Java code. The class files contain information about the classes that are included in the application.
Package files:
These are the files that contain information about the packages. A package is a collection of classes and other files.
Resource files:
These are the files that contain resources. Resources are files that contain information about the application.
Libraries:
These are the libraries that contain the code that is used by the application.
Java API:
This is the Java API that contains the classes and methods that are used by the application.
JDK Structure
 |
| JDK Structure |
Java Virtual Machine (JVM)
The Java Virtual Machine (JVM) is the runtime environment that executes Java code. It is an environment in which the Java language is compiled into bytecode.
JVM consists of the following parts:
Compiler: This part takes the Java code written in the source files and translates it into bytecode.
Class loader: This part takes the class files and the package files and loads them into the JVM.
Interpreter: This part takes the bytecode and translates it into native machine code.
Execution environment: This part handles the execution of the application. It contains the information about the system resources that are needed by the application.
Java Runtime Environment (JRE)
The Java Runtime Environment (JRE) is the software that is needed to run a Java application. It is usually installed with the Java development tools. The JRE can be downloaded from the Java web site at https://www.java.com
JRE contains the Java Runtime Environment. The Java Runtime Environment is a software environment that is used to run applications. It contains a virtual machine, a Java Virtual Machine (JVM), and the Java runtime system.
The JRE contains the following parts:
Class loader: This part loads the class files and package files.
Class file verifier: This part checks the consistency of the class files.
Interpreter: This part interprets the bytecode.
Execution environment: This part handles the execution of the application. It contains the information about the system resources that are needed by the application.
Java Development kit (JDK)
The Java Development Kit (JDK) is the software that is needed to develop Java applications. It contains the JRE and the Java development tools.
JDK is required to develop Java applications. It contains the JRE, which is used to run the applications, and the Java development tools, which are used to develop the applications.
How Java Platform Independent?
The Java programming language is platform independent. It means that the Java language can be used to create applications for any operating system. It is possible to write Java code and run it on any operating system.
Also read-Java Basic Concept {alertInfo}