by Java is a programming language and computing platform first released by Sun Microsystems in 1995. It is designed to be platform-independent, which means that code written in Java can run on a variety of different devices and operating systems without modification. Java is an object-oriented language, which means that it is based on the concept of “objects” that contain both data and the methods that operate on that data. It is widely used for developing enterprise-level applications, video games, mobile applications, and more. Java also has a large and active developer community, which has created a wide variety of libraries and frameworks to help developers work more efficiently and effectively.
History of JAVA
The history of Java can be traced back to the early 1990s, when a team of engineers at Sun Microsystems, led by James Gosling, began working on a project to create a new programming language for consumer electronic devices. This project was initially called “Oak,” but it was later renamed to “Java,” a name chosen to reflect the language’s cross-platform capabilities.
Java 1.0 was first released in 1995, and it quickly gained popularity among developers for its platform-independent, object-oriented features and its ability to run on a variety of different devices. The first version of Java was primarily used for developing applets, small, interactive programs that could run within a web browser.
In 1996, Sun Microsystems released Java 1.1, which included support for inner classes, RMI (Remote Method Invocation), and JDBC (Java Database Connectivity). This release made Java more suitable for developing enterprise-level applications.
Over the years, Java has continued to evolve and improve. Java 1.2, also known as “Java 2,” was released in 1998 and included significant changes to the language and its standard libraries. Java 5, released in 2004, introduced support for annotations and generics, which made the language more powerful and easier to use.
In 2011 Oracle Corporation acquired Sun Microsystems and become the owner of Java. After that, Java 8 was released in 2014, it introduced functional programming concepts, such as lambdas and streams, to the language. Java 11 was released in 2018 which was a long-term support (LTS) release, which means that it will be supported for a longer period of time than other releases. Java 15 was released in September 2021, which was the latest version of Java till the knowledge cutoff date.
Today, Java remains one of the most popular programming languages in the world, and it is widely used for developing a wide range of applications, including enterprise software, mobile apps, and video games.
JAVA versions
There have been several versions of the Java programming language since its initial release in 1995. Some of the notable versions include:
- Java 1.0: The first version of Java, released in 1995. It was primarily used for developing applets, small, interactive programs that could run within a web browser.
- Java 1.1: Released in 1996, this version included support for inner classes, RMI (Remote Method Invocation), and JDBC (Java Database Connectivity). This release made Java more suitable for developing enterprise-level applications.
- Java 2 (Java 1.2): Released in 1998, this version included significant changes to the language and its standard libraries. It was renamed to Java 2 to reflect the significant changes made in this release.
- Java 5: Released in 2004, this version introduced support for annotations and generics, which made the language more powerful and easier to use.
- Java 6: Released in 2006, it introduced scripting language support and dynamic language support, enhanced web service support and improved performance.
- Java 7: Released in 2011, it introduced support for multi-language strings, automatic resource management, and support for type-inferred ‘diamond’ operators.
- Java 8: Released in 2014, it introduced functional programming concepts, such as lambdas and streams, to the language. Also, it was the first release under Oracle’s ownership after acquiring Sun Microsystems.
- Java 9: Released in 2017, it introduced the Java Platform Module System (JPMS) which improved the maintainability and scalability of Java applications.
- Java 10: Released in 2018, it introduced local-variable type inference and the experimental Java-based JIT compiler, “Graal.”
- Java 11: Released in 2018, it was a long-term support (LTS) release, which means that it will be supported for a longer period of time than other releases.
- Java 12: Released in 2019, it introduced the switch expressions and text blocks as a preview language feature, which were later finalized in Java 13.
- Java 13: Released in 2019, it finalized the switch expressions and text blocks features introduced in Java 12.
- Java 14: Released in 2020, it introduced several new features like the pattern matching for instanceof, an improved version of the switch expressions and a new JDK Flight Recorder.
- Java 15: Released in September 2021, it introduced several new features like the hidden classes, sealed classes, and records.
Features of JAVA
Java is a powerful and versatile programming language that has several key features that make it well-suited for a wide range of applications:
- Platform-independent: Java code can run on a variety of different devices and operating systems without modification, making it a great choice for cross-platform development.
- Object-oriented: Java is based on the concept of “objects” that contain both data and the methods that operate on that data, making it easy to organize and manage code.
- Automatic memory management: Java automatically manages memory usage, which helps to reduce errors and improve application performance.
- Rich set of libraries: Java has a large and active developer community, which has created a wide variety of libraries and frameworks to help developers work more efficiently and effectively.
- Multi-threaded: Java supports the concurrent execution of multiple threads, which can improve application performance and responsiveness.
- Built-in support for networking: Java includes built-in support for common networking protocols, making it easy to develop network-enabled applications.
- Built-in support for security: Java includes built-in security features, such as sandboxing and code signing, that help to protect applications and users from malicious code.
- Garbage Collection: Java has built-in garbage collection which automatically deallocates memory for objects that are no longer in use, this helps to prevent memory leaks and improve application performance.
- Functional programming features: With Java 8, functional programming features like lambdas and streams were introduced, this made Java more powerful and easier to use.
- Improved performance: With each new release, Java is optimized for better performance, this is achieved by new features, better JIT compilers, and improved garbage collection algorithms.
Java Program Structure
A Java program typically consists of the following parts:
Package Declarations: The first line of a Java program is usually a package declaration. A package is a collection of related classes and interfaces that are grouped together.
Import statements: After the package declaration, you will typically see one or more import statements. These statements tell the Java compiler which classes or interfaces from other packages the program needs to use.
Class definition: A Java program must have at least one class definition. A class is a blueprint for an object, and it defines the properties and methods that an object of that class will have.
Main method: The main method is the entry point of the program, it is where the program starts execution. The main method is always named “main” and it is always defined within a class. It has a specific structure, it should be public, static, and have a return type of void, and it should have a String array parameter.
Method definitions: A class can contain any number of methods, which are the functions that the class can perform. Methods can have parameters, and they can return values.
Variable Declarations: A class can contain any number of variables, which are the properties of the class. Variables can be of different types, like int, String, double, etc.
Statements and Expressions: The program can contain any number of statements and expressions, that are used to perform different operations like assignment, mathematical calculations, function calls, etc.
public class HelloWorld {
public static void main(String[] args) {
System.out.println(“Hello, World!”);
}
}
This program has a single class called HelloWorld, which contains a single method called main. The main method contains a single statement that uses the println method of the System.out object to print the string “Hello, World!” to the console.
