Introduction to Java

Introduction to Java

Sun Microsystems launched Java in 1995, with an object-oriented approach that allows for the production of reusable code. Renowned for its security, speed, and platform independence, it remains one of the most popular programming languages, now owned by Oracle.

Java Applications

Java Applications includes

• Standalone Application
• Web Application
• Enterprise Application
• Mobile Enterprise

Java Features

• Object-Oriented
• Simple
• Secured
• Platform Independent
• Robust
• Portable
• Interpreted
• Distributed

Why Java is considered?

Java is a versatile and strong programming language known for its platform independence & object-oriented structure, which allows for the building of modular programs. Furthermore, its multithreading capabilities allow for the simultaneous execution of numerous computational processes, increasing efficiency and performance.

Java Virtual Machine (JVM)

The Java Virtual Machine (JVM) is required to run compiled Java code, which converts bytecode into machine language within the Java Runtime Environment (JRE). It manages key activities such as memory management, garbage collection, and threading to ensure that Java programs run efficiently.

Java Runtime Environment (JRE)

JRE, an essential component of JDK, includes the Java Class Library, tools, and a standalone JVM, which serves as the primary environment for running Java programs on a variety of devices. It acts as an intermediary layer above the operating system, executing Java bytecode and making it platform-independent.

Java Development Kit (JDK)

The JDK, an essential software toolkit for Java development, provides developers with object-oriented capabilities for creating Java programs. With its extensive collection of libraries and tools, it gives developers access to a private "Java Virtual Machine" and other critical resources for Java application development.

Difference between JDK, JRE, and JVM

• Java programs are created with the JDK (Java Development Kit). It includes coding, debugging, and compilation tools.
• The Java Runtime Environment (JRE) is used to execute Java programs. The JVM (Java Virtual Machine) and the necessary libraries are included.
• The Java Virtual Machine executes Java code. It runs Java programs and is a component of the JRE.

Working of Java

The JDK, a required software toolkit for Java development, provides developers with object-oriented capabilities for creating Java programs. With its extensive collection of libraries and tools, it gives developers access to a private "Java Virtual Machine" and other critical resources for Java application development.

Editions in Java

Java application has three editions such as:

1. Java Standard Edition
2. Java Micro Edition
3. Java Enterprise Edition

Java Architecture

The two main stages of Java architecture: are compile-time and runtime.

• The Java compiler (javac) compiles Java source code (.java files) into bytecode (.class files).
• The Java Virtual Machine (JVM) runs bytecode on the operating system, regardless of the computer hardware.