Java Evolution

Exploring Java Evolution: A Comprehensive Guide to Features Introduced in Each Java Version

Java, a cornerstone of modern programming, has undergone significant transformations since its inception. Each new release brings a host of features designed to enhance performance, streamline development, and expand the language’s capabilities. From its early days, where it introduced foundational concepts, to the latest versions that embrace cutting-edge technology, Java continues to evolve in response to the needs of developers and the demands of contemporary applications.

In this blog post, we’ll embark on a journey through Java’s evolution, uncovering the key features introduced with each version. We will delve into major enhancements, such as the introduction of records, pattern matching, and new garbage collectors, providing insights into how these features contribute to a more robust and efficient programming experience.

Whether you are a seasoned Java developer or a newcomer eager to understand the language’s progression, this guide will offer a comprehensive overview of what each version of Java has brought to the table. Join us as we explore how Java has transformed over the years, and discover the tools and features that have shaped the Java landscape.

Java 1.0 (1996)

Initial Release: Basic features such as the core API, AWT, and basic Java language constructs.

Explanation: The initial release of Java introduced the fundamental building blocks of the language, including the core API (Application Programming Interface), which provides essential classes and methods for programming, the AWT (Abstract Window Toolkit) for building graphical user interfaces (GUIs), and basic language constructs like loops, conditionals, and object-oriented programming principles.

Example:
public class HelloWorld {
    public static void main(String[] ar){
         System.out.println("Hello, World!"); // Prints "Hello, World!" to the console
    }
}

Java 1.1 (1997)

Inner Classes: Classes defined within other classes.

Explanation: Inner classes allow you to define a class within another class. This helps logically group classes that are only used in one place, increasing encapsulation and readability.

Example:
public class OuterClass {
    class InnerClass {
        void display() {
        System.out.println("Inner Class Method");
    }
}

JavaBeans: Reusable software components for Java.

Explanation: JavaBeans are classes that encapsulate many objects into a single object (the bean). They are used to create reusable software components that can be manipulated visually in a builder tool. A JavaBean follows certain conventions:

It should have a public no-argument constructor.

It should be serializable (can be converted into a byte stream and back).

It should have getter and setter methods to access its properties.

Importance: JavaBeans provide a standard way to handle complex entities in a simplified manner, making it easier to work with data in Java applications, especially in GUI applications and server-side components.

Example:
import java.io.Serializable;
public class MyBean implements Serializable {
   private String name;
   // No-argument constructor
   public MyBean() {}
    // Getter method for 'name' property
    public String getName() {
       return name;
   }
   // Setter method for 'name' property
   public void setName(String name) {
        this.name = name;
    }
}

JDBC: Java Database Connectivity, a standard API for database access.

Explanation: JDBC is a Java API that allows Java programs to connect to databases and execute SQL statements. It provides a set of interfaces and classes for querying and updating data in a database.

Importance: JDBC enables Java applications to interact with various databases, allowing for data storage, retrieval, and manipulation, which is crucial for data-driven applications.

Example:

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.ResultSet;

import java.sql.Statement;

public class JDBCDemo {

    public static void main(String[] args) throws Exception {

        // Establishing a connection to the database

        Connection con = DriverManager.getConnection(“jdbc:mysql://localhost:3306/mydb”, “user”, “password”);

        // Creating a statement object to execute SQL queries

        Statement stmt = con.createStatement();

        // Executing a SQL query and retrieving the results

        ResultSet rs = stmt.executeQuery(“SELECT * FROM mytable”);

        // Processing the results

        while (rs.next()) {

            System.out.println(rs.getString(1));

        }

        // Closing the connection

        con.close();

    }

}

RMI: Remote Method Invocation, allowing methods to be invoked from another Java Virtual Machine.

Explanation: RMI allows Java objects to communicate and invoke methods on an object located in another JVM, possibly on a different physical machine. It facilitates distributed computing.

Importance: RMI makes it easier to develop distributed applications, where components can communicate and share resources over a network.

Example:

import java.rmi.Remote;

import java.rmi.RemoteException;

// Defining a remote interface

public interface MyRemote extends Remote {

    String sayHello() throws RemoteException;

}

Reflection: Ability to inspect and manipulate classes at runtime.

Explanation: Reflection allows Java code to inspect and manipulate the properties of classes, methods, and fields at runtime. It provides the ability to dynamically create objects, call methods, and access fields.

Importance: Reflection is useful for debugging, testing, and developing flexible and dynamic applications (e.g., frameworks and libraries that work with different classes and objects at runtime).

Example:

import java.lang.reflect.Method;

public class ReflectionDemo {

    public static void main(String[] args) throws Exception {

        // Getting the Class object for String

        Class<?> clazz = Class.forName(“java.lang.String”);

        // Getting the Method object for the toUpperCase method

        Method method = clazz.getMethod(“toUpperCase”);

        // Invoking the method on an instance of String

        System.out.println(method.invoke(“hello”)); // Outputs “HELLO”

    }

}

AWT Event Model: Improved event handling in the Abstract Window Toolkit.

Explanation: The AWT Event Model introduced a new way of handling events (like button clicks) in GUI applications. It uses event listeners and event objects to handle user interactions more efficiently.

Importance: This model improves the responsiveness and maintainability of GUI applications by decoupling event handling logic from GUI components.

Example:

import java.awt.*;

import java.awt.event.*;

public class AWTEventDemo extends Frame implements ActionListener {

    Button button;

    public AWTEventDemo() {

        button = new Button(“Click Me”);

        button.addActionListener(this);

        add(button);

        setSize(300, 200);

        setLayout(new FlowLayout());

        setVisible(true);

    }

    public void actionPerformed(ActionEvent e) {

        System.out.println(“Button Clicked”);

    }

    public static void main(String[] args) {

        new AWTEventDemo();

    }

}

Java 1.2 (1998)

• Swing: A new GUI toolkit providing more powerful and flexible components.
  • Explanation: Swing is a part of Java Foundation Classes (JFC) that provides a richer set of GUI components than AWT. It includes components like buttons, tables, trees, and lists, which are more flexible and customizable.
  • Importance: Swing allows developers to create more sophisticated and visually appealing user interfaces with less effort compared to AWT.
  • Example:
    
    import javax.swing.*;
  • public class SwingDemo {
  •     public static void main(String[] args) {
  •         JFrame frame = new JFrame(“Swing Example”);
  •         JButton button = new JButton(“Click Me”);
  •         frame.add(button);
  •         frame.setSize(300, 200);
  •         frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  •         frame.setVisible(true);
  •     }
  • }
  • 
    
    
    
• Collections Framework: A unified architecture for representing and manipulating collections.
  • Explanation: The Collections Framework provides a set of interfaces and classes for storing and manipulating groups of data as a single unit (collections). It includes interfaces like List, Set, and Map, and classes like ArrayList, HashSet, and HashMap.
  • Importance: The framework simplifies the process of managing collections of data, providing reusable data structures and algorithms to work with them.
  • Example:
    
    import java.util.ArrayList;
  • public class CollectionsDemo {
  •     public static void main(String[] args) {
  •         ArrayList<String> list = new ArrayList<>();
  •         list.add(“Hello”);
  •         list.add(“World”);
  •         System.out.println(list);
  •     }
  • }
  • 
    
    
    
• Java Plug-in: Allows applets to run in a web browser using Sun’s JVM.
  • Explanation: The Java Plug-in enables Java applets (small Java programs that run within a web browser) to use Sun’s Java Virtual Machine (JVM) instead of the browser’s default JVM.
  • Importance: This ensures that applets run consistently across different browsers and platforms.
  • Example:
    
    // Applet example
  • import java.applet.Applet;
  • import java.awt.Graphics;
  • public class MyApplet extends Applet {
  •     public void paint(Graphics g) {
  •         g.drawString(“Hello, World”, 20, 20);
  •     }
  • }
  • 
    
    
    
• strictfp: Ensures consistent floating-point calculations across platforms.
  • Explanation: The strictfp keyword is used to restrict floating-point calculations to ensure portability and consistency across different platforms.
  • Importance: This is useful for applications requiring precise and predictable floating-point computations, such as scientific calculations.
  • Example:
    
    public strictfp class StrictfpDemo {
  •     public static void main(String[] args) {
  •         double num = 0.1;
  •         double result = num * num;
  •         System.out.println(result); // Outputs a consistent result on all platforms
  •     }
  • }
  • 
    
    
    

Java 1.3 (2000)

• HotSpot JVM: A high-performance JVM.
  • Explanation: HotSpot JVM is a highly optimized Java Virtual Machine known for its advanced performance features such as Just-In-Time (JIT) compilation and adaptive optimization. It improves the runtime efficiency of Java applications by dynamically optimizing code execution based on runtime behavior.
  • Importance: HotSpot JVM enhances the performance of Java applications by optimizing frequently executed code paths, making Java applications run faster and more efficiently.
  • Example: The benefits of HotSpot JVM are mostly internal and do not require specific code changes by developers. However, you can enable certain JVM flags to control its behavior:bashCopy code
    
    java -XX:+UseConcMarkSweepGC -XX:+PrintGCDetails MyApplication
  • 
    
    
    
• JNDI: Java Naming and Directory Interface.
  • Explanation: JNDI provides a unified interface for accessing various directory services (like LDAP) and naming systems. It allows Java applications to look up and access objects and resources in a directory.
  • Importance: JNDI simplifies accessing and managing resources such as database connections, configuration files, and distributed objects.
  • Example:
    
    import javax.naming.Context;
  • import javax.naming.InitialContext;
  • import javax.naming.NamingException;
  • import javax.sql.DataSource;
  • public class JNDIDemo {
  •     public static void main(String[] args) {
  •         try {
  •             // Setting up the context
  •             Context ctx = new InitialContext();
  •             // Looking up a DataSource
  •             DataSource ds = (DataSource) ctx.lookup(“java:/comp/env/jdbc/mydb”);
  •             System.out.println(“DataSource found: ” + ds);
  •         } catch (NamingException e) {
  •             e.printStackTrace();
  •         }
  •     }
  • }
  • 
    
    
    
• RMI over IIOP: RMI over Internet Inter-ORB Protocol.
  • Explanation: RMI over IIOP allows Java RMI (Remote Method Invocation) to work with CORBA (Common Object Request Broker Architecture) systems. It enables Java objects to interact with objects in CORBA-compliant systems over the IIOP protocol.
  • Importance: This interoperability feature allows Java applications to integrate with other distributed systems that use CORBA, expanding Java’s capability in distributed computing.
  • Example: This feature is often used in enterprise environments where Java systems need to interact with CORBA systems. Specific code examples are complex and usually involve enterprise infrastructure.
• JavaSound: A library for handling audio.
  • Explanation: JavaSound provides APIs for handling audio input, output, and processing. It supports various audio formats and allows for complex audio operations like mixing, playback, and recording.
  • Importance: JavaSound enables Java applications to work with audio data, which is essential for multimedia applications, games, and sound-based user interfaces.
  • Example:
    
    import javax.sound.sampled.AudioInputStream;
  • import javax.sound.sampled.AudioSystem;
  • import javax.sound.sampled.Clip;
  • public class JavaSoundDemo {
  •     public static void main(String[] args) {
  •         try {
  •             // Load an audio file
  •             AudioInputStream audioIn = AudioSystem.getAudioInputStream(JavaSoundDemo.class.getResource(“sound.wav”));
  •             Clip clip = AudioSystem.getClip();
  •             clip.open(audioIn);
  •             clip.start(); // Play the audio
  •             Thread.sleep(5000); // Wait for the audio to finish
  •             clip.close();
  •         } catch (Exception e) {
  •             e.printStackTrace();
  •         }
  •     }
  • }
  • 
    
    
    

Java 1.4 (2002)

• assert: A keyword used for debugging.
  • Explanation: The assert keyword allows you to include debugging assertions in your code. Assertions are statements that test assumptions made in the code. If an assertion fails, it throws an AssertionError.
  • Importance: Assertions are useful for catching bugs and verifying assumptions during development, though they can be disabled in production.
  • Example:
    
    public class AssertDemo {
  •     public static void main(String[] args) {
  •         int value = 5;
  •         assert value > 10 : “Value is less than 10”; // Throws AssertionError if condition is false
  •     }
  • }
  • 
    
    
    
• Regular Expressions (java.util.regex): Pattern matching and text processing.
  • Explanation: The java.util.regex package provides classes for working with regular expressions, which are patterns used to match sequences of characters in strings. This is useful for searching, replacing, and validating text.
  • Importance: Regular expressions simplify complex text processing tasks, such as validating user input, parsing data, and performing search and replace operations.
  • Example:
    
    import java.util.regex.Matcher;
  • import java.util.regex.Pattern;
  • public class RegexDemo {
  •     public static void main(String[] args) {
  •         String text = “The quick brown fox”;
  •         Pattern pattern = Pattern.compile(“quick”);
  •         Matcher matcher = pattern.matcher(text);
  •         if (matcher.find()) {
  •             System.out.println(“Found match: ” + matcher.group());
  •         }
  •     }
  • }
  • 
    
    
    
• NIO (New I/O): Improved I/O operations.
  • Explanation: NIO provides a more flexible and efficient way to handle I/O operations, such as reading and writing files and performing network communication. It introduces channels, buffers, and selectors for non-blocking I/O operations.
  • Importance: NIO allows for more efficient and scalable I/O operations, particularly useful for high-performance applications and server-side development.
  • Example:
    
    import java.nio.file.Files;
  • import java.nio.file.Paths;
  • public class NioDemo {
  •     public static void main(String[] args) {
  •         try {
  •             // Reading file content using NIO
  •             String content = new String(Files.readAllBytes(Paths.get(“file.txt”)));
  •             System.out.println(content);
  •         } catch (Exception e) {
  •             e.printStackTrace();
  •         }
  •     }
  • }
  • 
    
    
    
• Chained Exceptions: The ability to handle multiple exceptions in a single block.
  • Explanation: Chained exceptions allow you to link one exception to another, providing more context about the sequence of events leading to an error. This is done by using the Throwable class’s constructor that accepts another Throwable.
  • Importance: Chained exceptions make it easier to debug and understand complex error scenarios where one exception causes another.
  • Example:
    
    public class ChainedExceptionDemo {
  •     public static void main(String[] args) {
  •         try {
  •             throw new Exception(“First exception”);
  •         } catch (Exception e) {
  •             throw new RuntimeException(“Second exception”, e); // Chaining the first exception
  •         }
  •     }
  • }
  • 
    
    
    
• Logging API: A unified API for logging messages.
  • Explanation: The Logging API provides a standard way to log messages, warnings, and errors in Java applications. It offers different logging levels and allows for configuration of log output destinations.
  • Importance: The Logging API helps developers track and manage application behavior, errors, and performance issues in a consistent and configurable manner.
  • Example:
    
    import java.util.logging.Logger;
  • public class LoggingDemo {
  •     private static final Logger logger = Logger.getLogger(LoggingDemo.class.getName());
  •     public static void main(String[] args) {
  •         logger.info(“This is an informational message”);
  •         logger.warning(“This is a warning message”);
  •     }
  • }
  • 
    
    
    

Java 5.0 (2004)

• Generics: Parameterized types for stronger type checks.
  • Explanation: Generics enable you to create classes, interfaces, and methods with type parameters. They provide compile-time type safety by allowing you to specify the types of objects that can be used with a class or method.
  • Importance: Generics help prevent runtime errors by catching type-related issues at compile time, making code more robust and easier to maintain.
  • Example:
    
    import java.util.ArrayList;
  • import java.util.List;
  • public class GenericsDemo {
  •     public static void main(String[] args) {
  •         List<String> list = new ArrayList<>();
  •         list.add(“Hello”);
  •         // list.add(123); // Compile-time error due to type safety
  •         for (String s : list) {
  •             System.out.println(s);
  •         }
  •     }
  • }
  • 
    
    
    
• Metadata (Annotations): Adding metadata to code.
  • Explanation: Annotations provide a way to add metadata to Java code, which can be used by the compiler or runtime for various purposes. Annotations do not change the program’s behavior but provide additional information.
  • Importance: Annotations are used for configuration, documentation, and code analysis, enabling developers to attach metadata to code elements such as classes, methods, and fields.
  • Example:
    
    @Deprecated
  • public class DeprecatedClass {
  •     @Deprecated
  •     public void oldMethod() {
  •         // Old method
  •     }
  • }
  • 
    
    
    
• Enumerated Types: Defining a set of named constants.
  • Explanation: Enumerated types (enums) provide a way to define a collection of related constants in a type-safe manner. Enums help represent a fixed set of values.
  • Importance: Enums enhance code readability and maintainability by using descriptive names for constants instead of numeric values or strings.
  • Example:
    
    public enum Day {
  •     MONDAY, TUESDAY, WEDNESDAY, THURSDAY, FRIDAY, SATURDAY, SUNDAY
  • }
  • public class EnumDemo {
  •     public static void main(String[] args) {
  •         Day today = Day.MONDAY;
  •         System.out.println(“Today is: ” + today);
  •     }
  • }
  • 
    
    
    
• Enhanced for Loop: Simplified iteration over collections and arrays.
  • Explanation: The enhanced for loop provides a simpler syntax for iterating over arrays and collections. It eliminates the need for explicit iterators or index management.
  • Importance: The enhanced for loop improves code readability and reduces errors associated with manual iteration.
  • Example:
    
    public class EnhancedForLoopDemo {
  •     public static void main(String[] args) {
  •         String[] names = {“Alice”, “Bob”, “Charlie”};
  •         for (String name : names) {
  •             System.out.println(name);
  •         }
  •     }
  • }
  • 
    
    
    
• Varargs: Variable-length argument lists.
  • Explanation: Varargs allow you to pass a variable number of arguments to a method. This simplifies method calls when the number of arguments is not known in advance.
  • Importance: Varargs make method signatures more flexible and reduce the need for overloading methods with different argument counts.
  • Example:
    
    public class VarargsDemo {
  •     public static void main(String[] args) {
  •         printNumbers(1, 2, 3, 4, 5);
  •     }
  •     public static void printNumbers(int… numbers) {
  •         for (int number : numbers) {
  •             System.out.println(number);
  •         }
  •     }
  • }
  • 
    
    
    
• Static Imports: Importing static members of a class.
  • Explanation: Static imports allow you to use static members (fields and methods) of a class without qualifying them with the class name. This can make code more concise.
  • Importance: Static imports can simplify code by reducing verbosity, especially when using constants or utility methods.
  • Example:
    
    import static java.lang.Math.*;
  • public class StaticImportDemo {
  •     public static void main(String[] args) {
  •         double result = sqrt(25); // Using static import to call sqrt() without Math. prefix
  •         System.out.println(“Square root of 25 is: ” + result);
  •     }
  • }
  • 
    
    
    
• Autoboxing/Unboxing: Automatic conversion between primitives and their wrapper classes.
  • Explanation: Autoboxing and unboxing automatically convert between primitive types (like int, char) and their corresponding wrapper classes (like Integer, Character). This simplifies code by eliminating the need for manual conversions.
  • Importance: This feature enhances code readability and reduces boilerplate code related to type conversions.
  • Example:
    
    public class AutoboxingDemo {
  •     public static void main(String[] args) {
  •         Integer integer = 10; // Autoboxing: int to Integer
  •         int number = integer; // Unboxing: Integer to int
  •         System.out.println(“Number is: ” + number);
  •     }
  • }
  • 
    
    
    
• Concurrency Utilities: Enhanced support for concurrent programming.
  • Explanation: Concurrency utilities provide classes and interfaces for managing threads and synchronization more effectively. It includes classes like Executor, ConcurrentHashMap, and utilities for managing thread pools and tasks.
  • Importance: These utilities simplify concurrent programming by providing higher-level abstractions and tools for managing multiple threads and synchronization.
  • Example:
    
    import java.util.concurrent.ExecutorService;
  • import java.util.concurrent.Executors;
  • public class ConcurrencyDemo {
  •     public static void main(String[] args) {
  •         ExecutorService executor = Executors.newFixedThreadPool(2);
  •         executor.execute(() -> System.out.println(“Task 1”));
  •         executor.execute(() -> System.out.println(“Task 2”));
  •         executor.shutdown();
  •     }
  • }
  • 
    
    
    

Java 6 (2006)

• Scripting Support: Integration with scripting languages.
  • Explanation: Java 6 introduced the javax.script package, which allows you to use scripting languages like JavaScript (via the Rhino engine) within Java applications. This feature enables dynamic scripting and integration with other languages.
  • Importance: Scripting support allows for more flexibility and interaction with other scripting languages, making it easier to integrate dynamic scripting capabilities into Java applications.
  • Example:
    
    import javax.script.ScriptEngine;
  • import javax.script.ScriptEngineManager;
  • public class ScriptingDemo {
  •     public static void main(String[] args) throws Exception {
  •         ScriptEngineManager manager = new ScriptEngineManager();
  •         ScriptEngine engine = manager.getEngineByName(“JavaScript”);
  •         engine.eval(“print(‘Hello from JavaScript’)”);
  •     }
  • }
  • 
    
    
    
• JAXB: Java Architecture for XML Binding.
  • Explanation: JAXB provides a way to bind XML data to Java objects and vice versa. It simplifies the process of working with XML data by allowing Java objects to be marshaled (converted to XML) and unmarshaled (converted from XML).
  • Importance: JAXB makes it easier to work with XML in Java applications by providing a standard way to handle XML data and convert it to/from Java objects.
  • Example:
    
    import javax.xml.bind.JAXBContext;
  • import javax.xml.bind.JAXBException;
  • import javax.xml.bind.Marshaller;
  • public class JAXBExample {
  •     public static void main(String[] args) throws JAXBException {
  •         // Create a JAXB context and marshaller
  •         JAXBContext context = JAXBContext.newInstance(Person.class);
  •         Marshaller marshaller = context.createMarshaller();
  •         marshaller.setProperty(Marshaller.JAXB_FORMATTED_OUTPUT, true);
  •         // Create a person object
  •         Person person = new Person(“John”, “Doe”);
  •         // Marshal the person object to XML
  •         marshaller.marshal(person, System.out);
  •     }
  • }
  • // Example POJO class for JAXB
  • import javax.xml.bind.annotation.XmlRootElement;
  • @XmlRootElement
  • public class Person {
  •     private String firstName;
  •     private String lastName;
  •     public Person() {}
  •     public Person(String firstName, String lastName) {
  •         this.firstName = firstName;
  •         this.lastName = lastName;
  •     }
  •     public String getFirstName() {
  •         return firstName;
  •     }
  •     public void setFirstName(String firstName) {
  •         this.firstName = firstName;
  •     }
  •     public String getLastName() {
  •         return lastName;
  •     }
  •     public void setLastName(String lastName) {
  •         this.lastName = lastName;
  •     }
  • }
  • 
    
    
    
• Improved Web Services: Enhancements for working with web services.
  • Explanation: Java 6 improved support for web services by enhancing the javax.xml.ws package, which simplifies the creation and consumption of SOAP-based web services and RESTful services.
  • Importance: These enhancements make it easier to integrate and work with web services, which are crucial for distributed applications and services.
  • Example:
    
    import javax.xml.ws.Endpoint;
  • @WebService
  • public class MyWebService {
  •     @WebMethod
  •     public String sayHello(String name) {
  •         return “Hello, ” + name;
  •     }
  • }
  • public class WebServicePublisher {
  •     public static void main(String[] args) {
  •         Endpoint.publish(“http://localhost:8080/mywebservice”, new MyWebService());
  •     }
  • }
  • 
    
    
    
• Enhancements to the JVM: Various performance and feature improvements.
  • Explanation: Enhancements to the JVM in Java 6 included optimizations for performance, improved garbage collection, and better support for multi-core processors.
  • Importance: These improvements contribute to better runtime performance and efficiency for Java applications.
  • Example: Most JVM enhancements are internal and do not require specific code changes.
• Compiler API: Programmatic access to the Java compiler.
  • Explanation: The Compiler API provides tools for working with the Java compiler programmatically. It allows you to compile Java code dynamically from within a Java application.
  • Importance: This API is useful for tools and frameworks that need to compile Java code at runtime.
  • Example:
    
    import javax.tools.JavaCompiler;
  • import javax.tools.ToolProvider;
  • public class CompilerDemo {
  •     public static void main(String[] args) {
  •         JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();
  •         int result = compiler.run(null, null, null, “HelloWorld.java”);
  •         System.out.println(“Compilation result: ” + result);
  •     }
  • }
  • 
    
    
    

Java 7 (2011)

• Project Coin: Small language changes.
  • Explanation: Project Coin introduced several small language enhancements to simplify coding and improve readability. These changes include new features like the diamond operator and improved type inference.
  • Importance: Project Coin makes Java code more concise and easier to read by introducing small but impactful language improvements.
  • Example: Changes from Project Coin are detailed in other features listed below.
• Try-With-Resources Statement: Automatic resource management.
  • Explanation: The try-with-resources statement simplifies the management of resources (like files and sockets) by automatically closing them when the block completes. Resources must implement the AutoCloseable interface.
  • Importance: This feature reduces boilerplate code and minimizes resource leaks by ensuring that resources are closed properly.
  • Example:
    
    import java.io.BufferedReader;
  • import java.io.FileReader;
  • import java.io.IOException;
  • public class TryWithResourcesDemo {
  •     public static void main(String[] args) {
  •         try (BufferedReader reader = new BufferedReader(new FileReader(“file.txt”))) {
  •             String line;
  •             while ((line = reader.readLine()) != null) {
  •                 System.out.println(line);
  •             }
  •         } catch (IOException e) {
  •             e.printStackTrace();
  •         }
  •     }
  • }
  • 
    
    
    
• Diamond Operator: Simplified generic instantiation.
  • Explanation: The diamond operator (<>) allows you to omit generic type parameters on the right-hand side of an assignment, simplifying the instantiation of generic classes.
  • Importance: The diamond operator reduces verbosity and makes code easier to maintain by inferring the type parameters.
  • Example:
    
    import java.util.ArrayList;
  • import java.util.List;
  • public class DiamondOperatorDemo {
  •     public static void main(String[] args) {
  •         List<String> list = new ArrayList<>(); // Diamond operator used here
  •         list.add(“Hello”);
  •         System.out.println(list.get(0));
  •     }
  • }
  • 
    
    
    
• Switch on String: Allowing String in switch statements.
  • Explanation: Prior to Java 7, the switch statement only supported primitive types and enumerations. Java 7 introduced support for String in switch statements.
  • Importance: This feature enhances the flexibility of the switch statement by allowing it to work with String values.
  • Example:
    
    public class SwitchOnStringDemo {
  •     public static void main(String[] args) {
  •         String day = “Monday”;
  •         switch (day) {
  •             case “Monday”:
  •                 System.out.println(“Start of the week”);
  •                 break;
  •             case “Friday”:
  •                 System.out.println(“End of the week”);
  •                 break;
  •             default:
  •                 System.out.println(“Midweek”);
  •         }
  •     }
  • }
  • 
    
    
    
• Improved Type Inference for Generic Instance Creation: Enhanced type inference in generics.
  • Explanation: Type inference improvements in Java 7 make it easier to instantiate generic classes without having to specify the type parameters explicitly.
  • Importance: This simplifies code and reduces redundancy by allowing the compiler to infer the generic types.
  • Example:
    
    import java.util.HashMap;
  • import java.util.Map;
  • public class TypeInferenceDemo {
  •     public static void main(String[] args) {
  •         Map<String, Integer> map = new HashMap<>(); // Type inference used here
  •         map.put(“One”, 1);
  •         System.out.println(map.get(“One”));
  •     }
  • }
  • 
    
    
    
• Multi-Catch: Catching multiple exceptions in a single block.
  • Explanation: Multi-catch allows you to handle multiple exceptions in a single catch block, reducing code duplication.
  • Importance: This feature simplifies error handling when multiple exceptions need to be handled similarly.
  • Example:
    
    public class MultiCatchDemo {
  •     public static void main(String[] args) {
  •         try {
  •             int result = 10 / 0;
  •         } catch (ArithmeticException | NullPointerException e) {
  •             System.out.println(“Caught an exception: ” + e);
  •         }
  •     }
  • }
  • 
    
    
    
• NIO.2: Enhancements to the NIO (New I/O) library.
  • Explanation: NIO.2 introduced new APIs for file I/O, including support for file attributes, symbolic links, and asynchronous file operations. It improves upon the original NIO by adding more features and capabilities.
  • Importance: NIO.2 enhances file I/O operations, providing more functionality and better performance.
  • Example:
    
    import java.nio.file.Files;
  • import java.nio.file.Path;
  • import java.nio.file.Paths;
  • import java.nio.file.attribute.BasicFileAttributes;
  • public class NIO2Demo {
  •     public static void main(String[] args) {
  •         Path path = Paths.get(“file.txt”);
  •         try {
  •             BasicFileAttributes attrs = Files.readAttributes(path, BasicFileAttributes.class);
  •             System.out.println(“Creation time: ” + attrs.creationTime());
  •         } catch (Exception e) {
  •             e.printStackTrace();
  •         }
  •     }
  • }
  • 
    
    
    

Java 8 (2014)

• Lambda Expressions: Anonymous functions for functional programming.
  • Explanation: Lambda expressions allow you to write concise and readable code for instances where you need to pass behavior as parameters. They are used primarily with functional interfaces (interfaces with a single abstract method).
  • Importance: Lambdas simplify the implementation of functional interfaces and enhance code readability by removing boilerplate code.
  • Example:
    
    import java.util.Arrays;
  • import java.util.List;
  • public class LambdaDemo {
  •     public static void main(String[] args) {
  •         List<String> names = Arrays.asList(“Alice”, “Bob”, “Charlie”);
  •         names.forEach(name -> System.out.println(name)); // Lambda expression used here
  •     }
  • }
  • 
    
    
    
• Stream API: Processing sequences of elements.
  • Explanation: The Stream API allows you to perform functional-style operations on sequences of elements (e.g., collections) such as filtering, mapping, and reducing. It simplifies bulk data operations.
  • Importance: The Stream API enables more expressive and declarative data processing, improving code clarity and reducing boilerplate code.
  • Example:
    
    import java.util.Arrays;
  • import java.util.List;
  • public class StreamAPIDemo {
  •     public static void main(String[] args) {
  •         List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
  •         int sum = numbers.stream().filter(n -> n % 2 == 0).mapToInt(n -> n).sum();
  •         System.out.println(“Sum of even numbers: ” + sum);
  •     }
  • }
  • 
    
    
    
• java.time (New Date and Time API): Modern date and time handling.
  • Explanation: The java.time package introduces a new, more comprehensive date and time API, including classes like LocalDate, LocalTime, and ZonedDateTime. It replaces the old java.util.Date and java.util.Calendar classes.
  • Importance: The new API provides better support for date and time operations, including time zones and durations, and improves accuracy and usability.
  • Example:
    
    import java.time.LocalDate;
  • import java.time.LocalTime;
  • import java.time.ZonedDateTime;
  • public class DateTimeAPIDemo {
  •     public static void main(String[] args) {
  •         LocalDate date = LocalDate.now();
  •         LocalTime time = LocalTime.now();
  •         ZonedDateTime zonedDateTime = ZonedDateTime.now();
  •         System.out.println(“Date: ” + date);
  •         System.out.println(“Time: ” + time);
  •         System.out.println(“Zoned DateTime: ” + zonedDateTime);
  •     }
  • }
  • 
    
    
    
• Default Methods in Interfaces: Providing method implementations in interfaces.
  • Explanation: Default methods allow you to provide method implementations directly within interfaces. This enables you to add new methods to interfaces without breaking existing implementations.
  • Importance: Default methods support backward compatibility and provide more flexibility in interface design.
  • Example:
    
    interface MyInterface {
  •     default void defaultMethod() {
  •         System.out.println(“Default method”);
  •     }
  • }
  • public class DefaultMethodDemo implements MyInterface {
  •     public static void main(String[] args) {
  •         MyInterface obj = new DefaultMethodDemo();
  •         obj.defaultMethod(); // Calls the default method from the interface
  •     }
  • }
  • 
    
    
    
• Optional: A container for optional values.
  • Explanation: The Optional class represents a value that may or may not be present. It provides methods to handle cases where a value might be missing without using null.
  • Importance: Optional helps avoid NullPointerException and provides a more expressive way to handle optional values.
  • Example:
    
    import java.util.Optional;
  • public class OptionalDemo {
  •     public static void main(String[] args) {
  •         Optional<String> optionalValue = Optional.of(“Hello”);
  •         optionalValue.ifPresent(value -> System.out.println(“Value: ” + value));
  •     }
  • }
  • 
    
    
    
• Nashorn JavaScript Engine: A new JavaScript engine.
  • Explanation: Nashorn is a JavaScript engine that replaces the older Rhino engine. It provides better performance and integrates with the Java Virtual Machine.
  • Importance: Nashorn allows Java applications to execute JavaScript code with better performance and efficiency.
  • Example:
    
    import javax.script.ScriptEngine;
  • import javax.script.ScriptEngineManager;
  • public class NashornDemo {
  •     public static void main(String[] args) throws Exception {
  •         ScriptEngineManager manager = new ScriptEngineManager();
  •         ScriptEngine engine = manager.getEngineByName(“nashorn”);
  •         engine.eval(“print(‘Hello from Nashorn’)”);
  •     }
  • }
  • 
    
    
    
• Type Annotations: Annotations on type declarations.
  • Explanation: Type annotations allow you to apply annotations to type parameters and type uses, providing more flexibility in type checking and processing.
  • Importance: Type annotations enhance the ability to perform type checking and code analysis, improving code quality and safety.
  • Example:
    
    import java.lang.annotation.ElementType;
  • import java.lang.annotation.Retention;
  • import java.lang.annotation.RetentionPolicy;
  • import java.lang.annotation.Target;
  • @Retention(RetentionPolicy.RUNTIME)
  • @Target(ElementType.TYPE_PARAMETER)
  • public @interface NonNull {}
  • public class TypeAnnotationsDemo<@NonNull T> {
  •     public static void main(String[] args) {
  •         System.out.println(“Type annotations demo”);
  •     }
  • }
  • 
    
    
    

Java 9 (2017)

• Module System (Project Jigsaw): Modularity for Java applications.
  • Explanation: Java 9 introduced the module system, which allows you to modularize your applications and libraries. Modules define a set of packages and expose only the packages that are intended to be used by other modules.
  • Importance: The module system improves code organization, encapsulation, and dependency management, and enhances the maintainability of large codebases.
  • Example:
    
    // module-info.java
  • module com.example.myapp {
  •     exports com.example.myapp;
  • }
  • 
    
    
    
• JShell: Interactive Java shell for quick code testing.
  • Explanation: JShell provides an interactive REPL (Read-Eval-Print Loop) for quickly evaluating Java code snippets. It is useful for experimentation and learning.
  • Importance: JShell simplifies testing and experimenting with Java code without the need for creating a full application.
  • Example:
    
    // Run JShell and enter the following commands
  • jshell> int x = 10;
  • jshell> x + 5
  • $1 ==> 15
  • 
    
    
    
• Private Methods in Interfaces: Private methods in interfaces for code reuse.
  • Explanation: Java 9 allows private methods in interfaces, enabling you to define helper methods within interfaces that are not exposed to implementing classes.
  • Importance: Private methods enhance code reuse and maintainability in interfaces.
  • Example:
    
    interface MyInterface {
  •     private void privateMethod() {
  •         System.out.println(“Private method”);
  •     }
  •     default void publicMethod() {
  •         privateMethod();
  •     }
  • }
  • public class PrivateMethodDemo implements MyInterface {
  •     public static void main(String[] args) {
  •         MyInterface obj = new PrivateMethodDemo();
  •         obj.publicMethod();
  •     }
  • }
  • 
    
    
    
• Stream API Enhancements: Additional methods and improvements.
  • Explanation: Java 9 introduced enhancements to the Stream API, including new methods like takeWhile, dropWhile, and ofNullable, for more flexible and expressive stream processing.
  • Importance: These enhancements provide more powerful and concise ways to work with streams.
  • Example:
    
    import java.util.Arrays;
  • import java.util.List;
  • public class StreamAPIEnhancementsDemo {
  •     public static void main(String[] args) {
  •         List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5);
  •         numbers.stream()
  •               .takeWhile(n -> n < 4)
  •               .forEach(System.out::println); // Output: 1 2 3
  •     }
  • }
  • 
    
    
    
• Optional Improvements: Additional methods for Optional.
  • Explanation: Java 9 introduced new methods in the Optional class, such as ifPresentOrElse, or, and orElseThrow, providing more flexibility for handling optional values.
  • Importance: These improvements enhance the usability of Optional for handling missing values more effectively.
  • Example:
    
    import java.util.Optional;
  • public class OptionalImprovementsDemo {
  •     public static void main(String[] args) {
  •         Optional<String> optionalValue = Optional.of(“Hello”);
  •         optionalValue.ifPresentOrElse(
  •             value -> System.out.println(“Value: ” + value),
  •             () -> System.out.println(“Value is not present”)
  •         );
  •     }
  • }
  • 
    
    
    
• Diamond Operator Enhancements: Allowing diamond operator with anonymous inner classes.
  • Explanation: Java 9 extends the use of the diamond operator to anonymous inner classes, making generic instantiation more concise.
  • Importance: This enhancement reduces verbosity and improves code readability.
  • Example:
    
    import java.util.ArrayList;
  • import java.util.List;
  • public class DiamondOperatorEnhancementsDemo {
  •     public static void main(String[] args) {
  •         List<String> list = new ArrayList<>() { // Diamond operator with anonymous class
  •             {
  •                 add(“Hello”);
  •             }
  •         };
  •         System.out.println(list.get(0));
  •     }
  • }
  • 
    
    
    

Java 10 (2018)

• Local-Variable Type Inference: Introduction of var.
  • Explanation: Java 10 introduced the var keyword for local variable type inference, allowing the compiler to infer the type of a variable from the context.
  • Importance: This feature simplifies code by reducing verbosity and improving readability.
  • Example:
    
    public class LocalVariableTypeInferenceDemo {
  •     public static void main(String[] args) {
  •         var message = “Hello, World!”; // Type inferred as String
  •         System.out.println(message);
  •     }
  • }
  • 
    
    
    
• Application Class-Data Sharing: Improved class loading performance.
  • Explanation: Application class-data sharing (AppCDS) allows you to share class metadata between Java Virtual Machine (JVM) instances, improving startup performance.
  • Importance: This feature enhances application startup times and reduces memory usage.
  • Example: This feature is primarily a JVM performance improvement and does not require specific code changes.
• Garbage Collector Improvements: Enhancements to garbage collection.
  • Explanation: Java 10 includes various improvements to garbage collection, including better performance and reduced latency.
  • Importance: These improvements contribute to more efficient memory management and application performance.
  • Example: These improvements are internal to the JVM and do not require specific code changes.
• Thread-Local Handshakes: Improved JVM threading capabilities.
  • Explanation: Thread-local handshakes allow the JVM to safely execute certain operations on specific threads, improving thread management and performance.
  • Importance: This feature enhances thread handling and JVM performance.
  • Example: This feature is internal to the JVM and does not require specific code changes.

Java 11 (2018)

• HTTP Client API: New API for HTTP requests.
  • Explanation: Java 11 introduced a new HTTP Client API, which provides a more modern and efficient way to handle HTTP requests and responses compared to the older HttpURLConnection API.
  • Importance: The new API simplifies making HTTP requests and handling responses, with better support for modern HTTP features.
  • Example:
    
    import java.net.URI;
  • import java.net.http.HttpClient;
  • import java.net.http.HttpRequest;
  • import java.net.http.HttpResponse;
  • public class HTTPClientDemo {
  •     public static void main(String[] args) throws Exception {
  •         HttpClient client = HttpClient.newHttpClient();
  •         HttpRequest request = HttpRequest.newBuilder()
  •                 .uri(URI.create(“https://api.example.com/data”))
  •                 .build();
  •         HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
  •         System.out.println(“Response: ” + response.body());
  •     }
  • }
  • 
    
    
    
• String Methods: New methods for String manipulation.
  • Explanation: Java 11 introduced new String methods such as strip, isBlank, lines, and repeat, providing more functionality for string manipulation.
  • Importance: These methods enhance the ease of working with strings and reduce the need for manual manipulation.
  • Example:
    
    public class StringMethodsDemo {
  •     public static void main(String[] args) {
  •         String text = ”  Hello, World!  “;
  •         System.out.println(“Stripped: ” + text.strip());
  •         System.out.println(“Is blank: ” + text.isBlank());
  •         System.out.println(“Lines:”);
  •         text.lines().forEach(System.out::println);
  •         System.out.println(“Repeated: ” + “Hi”.repeat(3));
  •     }
  • }
  • 
    
    
    
• Local-Variable Syntax for Lambda Parameters: var for lambda parameters.
  • Explanation: Java 11 allows the use of var for lambda parameters, enabling local-variable type inference in lambda expressions.
  • Importance: This feature improves readability and consistency with local-variable type inference.
  • Example:
    
    import java.util.function.Function;
  • public class LambdaParametersDemo {
  •     public static void main(String[] args) {
  •         Function<String, Integer> stringLength = (var s) -> s.length();
  •         System.out.println(“Length of ‘Hello’: ” + stringLength.apply(“Hello”));
  •     }
  • }
  • 
    
    
    
• Flight Recorder: Low-overhead performance monitoring.
  • Explanation: Java 11 includes Flight Recorder, a low-overhead monitoring tool that provides detailed insights into JVM performance and application behavior.
  • Importance: Flight Recorder helps diagnose performance issues and monitor applications with minimal impact on performance.
  • Example: Flight Recorder is primarily a JVM tool and does not require specific code changes.
• Deprecation of Nashorn: Removal of the Nashorn JavaScript engine.
  • Explanation: Java 11 marks the deprecation of the Nashorn JavaScript engine, signaling its eventual removal in future versions.
  • Importance: Users of Nashorn should consider alternative JavaScript engines or solutions.
  • Example: Users should migrate to other solutions or update their code as needed.
• Removal of Java EE and CORBA Modules: Java EE and CORBA modules are removed from the JDK.
  • Explanation: Java 11 removes the Java EE and CORBA modules from the JDK, as they are no longer part of the core Java platform.
  • Importance: Users relying on these modules should update their dependencies or use alternative libraries.
  • Example: Users should migrate to external libraries or frameworks that provide the functionality previously available in these modules.

Java 12 (2019)

• Switch Expressions (Preview): Enhanced switch statements with expressions.
  • Explanation: Java 12 introduces preview features for switch expressions, allowing switch to be used as an expression and return a value.
  • Importance: This feature simplifies switch statements and enhances code readability.
  • Example:
    
    public class SwitchExpressionsDemo {
  •     public static void main(String[] args) {
  •         String day = “Monday”;
  •         String typeOfDay = switch (day) {
  •             case “Monday” -> “Start of the week”;
  •             case “Friday” -> “End of the week”;
  •             default -> “Midweek”;
  •         };
  •         System.out.println(“Type of day: ” + typeOfDay);
  •     }
  • }
  • 
    
    
    
• JVM Constants API: API for JVM constants.
  • Explanation: The JVM Constants API provides a way to access and manipulate constants used by the JVM.
  • Importance: This API allows for more flexible and efficient handling of constants.
  • Example: The JVM Constants API is used internally and does not require specific code changes for most applications.
• Shenandoah Garbage Collector (Experimental): Low-latency garbage collector.
  • Explanation: Shenandoah is a low-latency garbage collector aimed at reducing pause times by performing garbage collection concurrently with application threads.
  • Importance: Shenandoah improves the performance of applications that require low-latency garbage collection.
  • Example: Shenandoah is primarily a JVM feature and does not require specific code changes.
• Microbenchmark Suite: Performance measurement tools.
  • Explanation: Java 12 includes a new microbenchmark suite for measuring performance and benchmarking JVM features.
  • Importance: The microbenchmark suite helps developers measure performance and compare different JVM configurations.
  • Example: This feature is used for performance testing and does not require specific code changes.

Java 13 (2019)

• Text Blocks (Preview): Multi-line string literals.
  • Explanation: Java 13 introduces preview features for text blocks, which simplify the creation of multi-line string literals.
  • Importance: Text blocks make it easier to work with large or multi-line strings, improving code readability.
  • Example:
    
    public class TextBlocksDemo {
  •     public static void main(String[] args) {
  •         String text = “””
  •                       This is a text block.
  •                       It can span multiple lines.
  •                       “””;
  •         System.out.println(text);
  •     }
  • }
  • 
    
    
    
• Dynamic CDS Archives: Improve class-data sharing.
  • Explanation: Dynamic CDS (Class Data Sharing) archives allow the creation of class-data sharing archives at runtime, improving application startup times and reducing memory usage.
  • Importance: This feature enhances the efficiency of class loading and memory usage.
  • Example: Dynamic CDS archives are a JVM feature and do not require specific code changes.
• ZGC Improvements: Enhancements to the Z Garbage Collector.
  • Explanation: Java 13 includes various improvements to the Z Garbage Collector (ZGC), including better performance and reduced pause times.
  • Importance: These improvements enhance the performance of applications using ZGC for garbage collection.
  • Example: ZGC improvements are primarily a JVM feature and do not require specific code changes.

Java 14 (2020)

• Switch Expressions (Standard Feature): Full support for switch expressions.
  • Explanation: Java 14 officially includes switch expressions as a standard feature, allowing switch to be used as an expression and return a value.
  • Importance: This feature simplifies switch statements and enhances code readability.
  • Example:
    
    public class SwitchExpressionsDemo {
  •     public static void main(String[] args) {
  •         String day = “Monday”;
  •         String typeOfDay = switch (day) {
  •             case “Monday” -> “Start of the week”;
  •             case “Friday” -> “End of the week”;
  •             default -> “Midweek”;
  •         };
  •         System.out.println(“Type of day: ” + typeOfDay);
  •     }
  • }
  • 
    
    
    
• NullPointerException.getMessage(): Enhanced exception messages.
  • Explanation: Java 14 improves NullPointerException by providing more detailed messages that include the name of the variable that caused the exception.
  • Importance: This enhancement makes debugging NullPointerException easier and more informative.
  • Example:
    
    public class NullPointerExceptionDemo {
  •     public static void main(String[] args) {
  •         String text = null;
  •         try {
  •             text.length();
  •         } catch (NullPointerException e) {
  •             System.out.println(e.getMessage());
  •         }
  •     }
  • }
  • 
    
    
    
• Records (Preview): Immutable data classes.
  • Explanation: Java 14 introduces records as a preview feature, providing a concise way to define immutable data classes with automatically generated methods such as equals, hashCode, and toString.
  • Importance: Records simplify the creation of data-centric classes and reduce boilerplate code.
  • Example:
    
    public record Point(int x, int y) {}
  • public class RecordsDemo {
  •     public static void main(String[] args) {
  •         Point p = new Point(1, 2);
  •         System.out.println(p); // Output: Point[x=1, y=2]
  •     }
  • }
  • 
    
    
    
• Foreign-Memory Access API (Incubator): Access to off-heap memory.
  • Explanation: The Foreign-Memory Access API allows Java programs to safely and efficiently access off-heap memory outside the Java heap.
  • Importance: This API provides a way to interact with native memory and improves performance for certain use cases.
  • Example: The Foreign-Memory Access API is an incubator feature and requires specific use cases and configurations.
• JVM Improvements: Various JVM enhancements.
  • Explanation: Java 14 includes various improvements to the JVM, such as performance optimizations and new features.
  • Importance: These improvements contribute to overall JVM performance and efficiency.
  • Example: JVM improvements are primarily internal and do not require specific code changes.

Java 15 (2020)

• Text Blocks (Standard Feature): Full support for text blocks.
  • Explanation: Java 15 officially includes text blocks as a standard feature, making it easier to work with multi-line string literals.
  • Importance: Text blocks improve code readability and simplify handling of multi-line strings.
  • Example:
    
    public class TextBlocksDemo {
  •     public static void main(String[] args) {
  •         String text = “””
  •                       This is a text block.
  •                       It can span multiple lines.
  •                       “””;
  •         System.out.println(text);
  •     }
  • }
  • 
    
    
    
• Sealed Classes (Preview): Restrict class inheritance.
  • Explanation: Sealed classes allow you to restrict which classes can extend or implement them, providing better control over class hierarchies.
  • Importance: Sealed classes improve design and maintainability by controlling inheritance.
  • Example:
    
    public sealed class Shape permits Circle, Square {}
  • public final class Circle extends Shape {}
  • public final class Square extends Shape {}
  • public class SealedClassesDemo {
  •     public static void main(String[] args) {
  •         Shape shape = new Circle();
  •         System.out.println(“Shape is an instance of: ” + shape.getClass().getSimpleName());
  •     }
  • }
  • 
    
    
    
• Hidden Classes: Support for dynamic languages.
  • Explanation: Hidden classes are a new type of class that can be used by frameworks and dynamic languages for better integration with the JVM.
  • Importance: This feature enhances the ability of dynamic languages and frameworks to work with the JVM.
  • Example: Hidden classes are primarily used by frameworks and dynamic languages and do not require specific code changes.
• ZGC Improvements: Enhanced Z Garbage Collector features.
  • Explanation: Java 15 includes improvements to the Z Garbage Collector (ZGC), including better performance and reduced pause times.
  • Importance: These enhancements improve the performance of applications using ZGC for garbage collection.
  • Example: ZGC improvements are primarily a JVM feature and do not require specific code changes.
• Foreign-Memory Access API (Incubator): Continued development.
  • Explanation: The Foreign-Memory Access API continues to be incubated, with further development and improvements.
  • Importance: This API provides a way to interact with native memory and improves performance for certain use cases.
  • Example: The Foreign-Memory Access API is an incubator feature and requires specific use cases and configurations.

Java 16 (2021)

• JEP 338: Unix-Domain Socket Support: Support for Unix domain sockets.
  • Explanation: Java 16 adds support for Unix domain sockets, allowing Java applications to communicate with native processes using Unix domain sockets.
  • Importance: This feature enables better integration with native processes and applications on Unix-like systems.
  • Example:
    
    import java.net.InetSocketAddress;
  • import java.net.SocketAddress;
  • import java.net.SocketChannel;
  • public class UnixDomainSocketDemo {
  •     public static void main(String[] args) throws Exception {
  •         SocketAddress address = new UnixDomainSocketAddress(“/path/to/socket”);
  •         try (SocketChannel channel = SocketChannel.open()) {
  •             channel.connect(address);
  •             // Communication with the native process
  •         }
  •     }
  • }
  • 
    
    
    
• JEP 394: Pattern Matching for instanceof: Simplified type checks.
  • Explanation: Java 16 introduces pattern matching for the instanceof operator, allowing you to combine type checks and casting in a single operation.
  • Importance: This feature simplifies code and improves readability when performing type checks.
  • Example:
    
    public class PatternMatchingDemo {
  •     public static void main(String[] args) {
  •         Object obj = “Hello”;
  •         if (obj instanceof String s) {
  •             System.out.println(“String length: ” + s.length());
  •         }
  •     }
  • }
  • 
    
    
    
• JEP 395: Records: Records become a standard feature.
  • Explanation: Java 16 officially includes records as a standard feature, providing a concise way to define immutable data classes.
  • Importance: Records simplify the creation of data-centric classes and reduce boilerplate code.
  • Example:
    
    public record Point(int x, int y) {}
  • public class RecordsDemo {
  •     public static void main(String[] args) {
  •         Point p = new Point(1, 2);
  •         System.out.println(p); // Output: Point[x=1, y=2]
  •     }
  • }
  • 
    
    
    
• JEP 338: Unix-Domain Socket Support: Support for Unix domain sockets.
  • Explanation: Java 16 adds support for Unix domain sockets, allowing Java applications to communicate with native processes using Unix domain sockets.
  • Importance: This feature enables better integration with native processes and applications on Unix-like systems.
  • Example:
    
    import java.net.InetSocketAddress;
  • import java.net.SocketAddress;
  • import java.net.SocketChannel;
  • public class UnixDomainSocketDemo {
  •     public static void main(String[] args) throws Exception {
  •         SocketAddress address = new UnixDomainSocketAddress(“/path/to/socket”);
  •         try (SocketChannel channel = SocketChannel.open()) {
  •             channel.connect(address);
  •             // Communication with the native process
  •         }
  •     }
  • }
  • 
    
    
    
• JEP 394: Pattern Matching for instanceof: Simplified type checks.
  • Explanation: Java 16 introduces pattern matching for the instanceof operator, allowing you to combine type checks and casting in a single operation.
  • Importance: This feature simplifies code and improves readability when performing type checks.
  • Example:
    
    public class PatternMatchingDemo {
  •     public static void main(String[] args) {
  •         Object obj = “Hello”;
  •         if (obj instanceof String s) {
  •             System.out.println(“String length: ” + s.length());
  •         }
  •     }
  • }
  • 
    
    
    
• JEP 395: Records: Records become a standard feature.
  • Explanation: Java 16 officially includes records as a standard feature, providing a concise way to define immutable data classes.
  • Importance: Records simplify the creation of data-centric classes and reduce boilerplate code.
  • Example:
    
    public record Point(int x, int y) {}
  • public class RecordsDemo {
  •     public static void main(String[] args) {
  •         Point p = new Point(1, 2);
  •         System.out.println(p); // Output: Point[x=1, y=2]
  •     }
  • }
  • 
    
    
    
• JEP 338: Unix-Domain Socket Support: Support for Unix domain sockets.
  • Explanation: Java 16 adds support for Unix domain sockets, allowing Java applications to communicate with native processes using Unix domain sockets.
  • Importance: This feature enables better integration with native processes and applications on Unix-like systems.
  • Example:
    
    import java.net.InetSocketAddress;
  • import java.net.SocketAddress;
  • import java.net.SocketChannel;
  • public class UnixDomainSocketDemo {
  •     public static void main(String[] args) throws Exception {
  •         SocketAddress address = new UnixDomainSocketAddress(“/path/to/socket”);
  •         try (SocketChannel channel = SocketChannel.open()) {
  •             channel.connect(address);
  •             // Communication with the native process
  •         }
  •     }
  • }
  • 
    
    
    
• JEP 394: Pattern Matching for instanceof: Simplified type checks.
  • Explanation: Java 16 introduces pattern matching for the instanceof operator, allowing you to combine type checks and casting in a single operation.
  • Importance: This feature simplifies code and improves readability when performing type checks.
  • Example:
    
    public class PatternMatchingDemo {
  •     public static void main(String[] args) {
  •         Object obj = “Hello”;
  •         if (obj instanceof String s) {
  •             System.out.println(“String length: ” + s.length());
  •         }
  •     }
  • }
  • 
    
    
    
• JEP 395: Records: Records become a standard feature.
  • Explanation: Java 16 officially includes records as a standard feature, providing a concise way to define immutable data classes.
  • Importance: Records simplify the creation of data-centric classes and reduce boilerplate code.
  • Example:
    
    public record Point(int x, int y) {}
  • public class RecordsDemo {
  •     public static void main(String[] args) {
  •         Point p = new Point(1, 2);
  •         System.out.println(p); // Output: Point[x=1, y=2]
  •     }
  • }
  • 
    
    
    

Java 17 (2021)

• Sealed Classes: Sealed classes become a standard feature.
  • Explanation: Java 17 officially includes sealed classes as a standard feature, allowing you to restrict which classes can extend or implement them.
  • Importance: This feature provides better control over class hierarchies and improves design.
  • Example:
    
    public sealed class Shape permits Circle, Square {}
  • public final class Circle extends Shape {}
  • public final class Square extends Shape {}
  • public class SealedClassesDemo {
  •     public static void main(String[] args) {
  •         Shape shape = new Circle();
  •         System.out.println(“Shape is an instance of: ” + shape.getClass().getSimpleName());
  •     }
  • }
  • 
    
    
    
• Pattern Matching for Switch (Preview): Enhanced switch statements.
  • Explanation: Java 17 introduces pattern matching for switch statements as a preview feature, allowing you to use patterns in switch expressions for more flexible and concise handling of multiple cases.
  • Importance: This feature simplifies complex switch statements and improves readability.
  • Example:
    
    public class PatternMatchingForSwitchDemo {
  •     public static void main(String[] args) {
  •         Object obj = “Hello”;
  •         String result = switch (obj) {
  •             case Integer i -> “Integer: ” + i;
  •             case String s -> “String: ” + s;
  •             default -> “Other”;
  •         };
  •         System.out.println(result);
  •     }
  • }
  • 
    
    
    
• Foreign Function & Memory API (Incubator): Access to native code and memory.
  • Explanation: The Foreign Function & Memory API allows Java programs to interact with native code and memory more safely and efficiently.
  • Importance: This API provides a way to work with native code and off-heap memory without requiring JNI (Java Native Interface).
  • Example: The Foreign Function & Memory API is an incubator feature and requires specific use cases and configurations.
• JEP 391: macOS/AArch64 Port: Support for macOS on AArch64.
  • Explanation: Java 17 adds support for the macOS/AArch64 platform, enabling Java applications to run on Apple Silicon (M1 and later) Macs.
  • Importance: This feature improves compatibility and performance for Java applications on Apple Silicon.
  • Example: This feature is primarily a JVM enhancement and does not require specific code changes.
• JEP 389: Foreign Function & Memory API (Incubator): Continued development.
  • Explanation: The Foreign Function & Memory API continues to be incubated, with further development and improvements.
  • Importance: This API provides a way to interact with native code and off-heap memory without requiring JNI (Java Native Interface).
  • Example: The Foreign Function & Memory API is an incubator feature and requires specific use cases and configurations.
• JEP 391: macOS/AArch64 Port: Support for macOS on AArch64.
  • Explanation: Java 17 adds support for the macOS/AArch64 platform, enabling Java applications to run on Apple Silicon (M1 and later) Macs.
  • Importance: This feature improves compatibility and performance for Java applications on Apple Silicon.
  • Example: This feature is primarily a JVM enhancement and does not require specific code changes.

Java 18 (2022)

• JEP 396: Strongly Encapsulate JDK Internals: Encapsulation of internal APIs.
  • Explanation: Java 18 strengthens the encapsulation of internal JDK APIs, improving the modularity and security of the Java platform.
  • Importance: This change helps prevent unintended usage of internal APIs and promotes better modularization.
  • Example: Developers using internal APIs should update their code to use supported public APIs instead.
• JEP 395: Records: Records become a standard feature.
  • Explanation: Java 16 officially includes records as a standard feature, providing a concise way to define immutable data classes.
  • Importance: Records simplify the creation of data-centric classes and reduce boilerplate code.
  • Example:
    
    public record Point(int x, int y) {}
  • public class RecordsDemo {
  •     public static void main(String[] args) {
  •         Point p = new Point(1, 2);
  •         System.out.println(p); // Output: Point[x=1, y=2]
  •     }
  • }
  • 
    
    
    
• JEP 395: Records: Records become a standard feature.
  • Explanation: Java 16 officially includes records as a standard feature, providing a concise way to define immutable data classes.
  • Importance: Records simplify the creation of data-centric classes and reduce boilerplate code.
  • Example:
    
    public record Point(int x, int y) {}
  • public class RecordsDemo {
  •     public static void main(String[] args) {
  •         Point p = new Point(1, 2);
  •         System.out.println(p); // Output: Point[x=1, y=2]
  •     }
  • }
  • 
    
    
    
• JEP 391: macOS/AArch64 Port: Support for macOS on AArch64.
  • Explanation: Java 17 adds support for the macOS/AArch64 platform, enabling Java applications to run on Apple Silicon (M1 and later) Macs.
  • Importance: This feature improves compatibility and performance for Java applications on Apple Silicon.
  • Example: This feature is primarily a JVM enhancement and does not require specific code changes.
• JEP 396: Strongly Encapsulate JDK Internals: Encapsulation of internal APIs.
  • Explanation: Java 18 strengthens the encapsulation of internal JDK APIs, improving the modularity and security of the Java platform.
  • Importance: This change helps prevent unintended usage of internal APIs and promotes better modularization.
  • Example: Developers using internal APIs should update their code to use supported public APIs instead.

Java 19 (2022)

• JEP 425: Virtual Threads (Second Preview): Lightweight concurrency with virtual threads.
  • Explanation: Java 19 continues the preview of virtual threads, which provide a lightweight and scalable concurrency model for Java applications.
  • Importance: Virtual threads aim to simplify concurrency and improve scalability for Java applications.
  • Example:
    
    import java.util.concurrent.Executors;
  • import java.util.concurrent.ExecutorService;
  • public class VirtualThreadsDemo {
  •     public static void main(String[] args) {
  •         ExecutorService executor = Executors.newVirtualThreadExecutor();
  •         executor.submit(() -> {
  •             System.out.println(“Running in a virtual thread!”);
  •         });
  •         executor.shutdown();
  •     }
  • }
  • 
    
    
    
• JEP 431: Sequenced Collections: New collections API.
  • Explanation: Java 19 introduces sequenced collections, a new collections API that provides better support for sequential access and iteration.
  • Importance: Sequenced collections enhance the flexibility and usability of collections in Java.
  • Example:
    
    import java.util.List;
  • import java.util.SequencedCollection;
  • public class SequencedCollectionsDemo {
  •     public static void main(String[] args) {
  •         SequencedCollection<String> seqColl = List.of(“A”, “B”, “C”);
  •         seqColl.forEach(System.out::println);
  •     }
  • }
  • 
    
    
    
• JEP 430: Scoped Values (Incubator): Scoped values for safe data sharing.
  • Explanation: Scoped values provide a way to share data safely and efficiently within a specific scope, improving the management of contextual information.
  • Importance: Scoped values enhance the safety and efficiency of data sharing in concurrent applications.
  • Example: Scoped values are an incubator feature and require specific use cases and configurations.

Java 20 (2023)

• JEP 431: Sequenced Collections: Sequenced collections become standard.
  • Explanation: Java 20 officially includes sequenced collections as a standard feature, providing better support for sequential access and iteration.
  • Importance: Sequenced collections enhance the flexibility and usability of collections in Java.
  • Example:
    
    import java.util.List;
  • import java.util.SequencedCollection;
  • public class SequencedCollectionsDemo {
  •     public static void main(String[] args) {
  •         SequencedCollection<String> seqColl = List.of(“A”, “B”, “C”);
  •         seqColl.forEach(System.out::println);
  •     }
  • }
  • 
    
    
    
• JEP 419: Foreign Function & Memory API (Second Incubator): Continued development.
  • Explanation: The Foreign Function & Memory API continues to be incubated, with further development and improvements.
  • Importance: This API provides a way to interact with native code and off-heap memory without requiring JNI (Java Native Interface).
  • Example: The Foreign Function & Memory API is an incubator feature and requires specific use cases and configurations.
• JEP 432: Pattern Matching for Switch (Standard): Pattern matching for switch becomes standard.
  • Explanation: Java 20 officially includes pattern matching for switch statements, allowing you to use patterns in switch expressions for more flexible and concise handling of multiple cases.
  • Importance: This feature simplifies complex switch statements and improves readability.
  • Example:
    
    public class PatternMatchingForSwitchDemo {
  •     public static void main(String[] args) {
  •         Object obj = “Hello”;
  •         String result = switch (obj) {
  •             case Integer i -> “Integer: ” + i;
  •             case String s -> “String: ” + s;
  •             default -> “Other”;
  •         };
  •         System.out.println(result);
  •     }
  • }
  • 
    
    
    
• JEP 429: Record Patterns (Second Preview): Enhanced record patterns.
  • Explanation: Java 20 continues the preview of record patterns, which improve pattern matching for records and enhance data handling.
  • Importance: Record patterns simplify code when working with records and improve data processing.
  • Example:
    
    public class RecordPatternsDemo {
  •     public static void main(String[] args) {
  •         Point p = new Point(1, 2);
  •         if (p instanceof Point(int x, int y)) {
  •             System.out.println(“Point coordinates: x=” + x + “, y=” + y);
  •         }
  •     }
  • }
  • record Point(int x, int y) {}
  • 
    
    
  • Java 21 (2023)

• JEP 444: String Templates (Preview): Simplified string formatting.
  • Explanation: String Templates introduce a new way to embed expressions within strings, allowing for more readable and maintainable code.
  • Importance: This feature simplifies complex string formatting and improves code clarity.
  • Example:
    
    public class StringTemplatesDemo {
  •     public static void main(String[] args) {
  •         String name = “World”;
  •         String message = STR.”Hello, {name}!”;
  •         System.out.println(message); // Output: Hello, World!
  •     }
  • }
  • 
    
    
    
• JEP 435: Generational ZGC: New garbage collector.
  • Explanation: The Generational Z Garbage Collector (ZGC) introduces generational support for the ZGC, aiming to improve garbage collection performance for applications with large heaps.
  • Importance: This feature enhances the efficiency and predictability of garbage collection in applications with large memory requirements.
  • Example: This feature is primarily a JVM enhancement and does not require specific code changes.
• JEP 426: unnamed patterns and variables: Support for unnamed patterns and variables.
  • Explanation: Java 21 introduces unnamed patterns and variables, allowing developers to use _ as a placeholder for unused patterns and variables, simplifying code and improving readability.
  • Importance: This feature helps reduce boilerplate code and improve the clarity of patterns and variables.
  • Example:
    
    public class UnnamedPatternsDemo {
  •     public static void main(String[] args) {
  •         Object obj = “Hello”;
  •         switch (obj) {
  •             case Integer _ -> System.out.println(“Integer”);
  •             case String _ -> System.out.println(“String”);
  •             default -> System.out.println(“Other”);
  •         }
  •     }
  • }
  • 
    
    
    

Java 22 (2024)

• JEP 446: Scoped Values (Standard): Scoped values become standard.
  • Explanation: Scoped values are officially included as a standard feature, providing a way to manage contextual data efficiently within a specific scope.
  • Importance: This feature enhances data sharing in concurrent and parallel programming, improving safety and efficiency.
  • Example:
    
    public class ScopedValuesDemo {
  •     private static final ScopedValue<String> scopedValue = ScopedValue.newInstance();
  •     public static void main(String[] args) {
  •         ScopedValue.set(scopedValue, “Hello”);
  •         Runnable task = () -> {
  •             String value = ScopedValue.get(scopedValue);
  •             System.out.println(“Scoped value: ” + value);
  •         };
  •         new Thread(task).start();
  •     }
  • }
  • 
    
    
    
• JEP 443: Foreign Function & Memory API (Standard): Foreign Function & Memory API becomes standard.
  • Explanation: The Foreign Function & Memory API is officially included as a standard feature, enabling safer and more efficient interaction with native code and off-heap memory.
  • Importance: This feature allows developers to interact with native code without using JNI, making integration with native systems easier and more efficient.
  • Example:
    
    import jdk.incubator.foreign.*;
  • public class ForeignMemoryDemo {
  •     public static void main(String[] args) {
  •         try (MemorySegment segment = MemorySegment.allocateNative(4)) {
  •             segment.set(ValueLayout.JAVA_INT, 0, 42);
  •             int value = segment.get(ValueLayout.JAVA_INT, 0);
  •             System.out.println(“Value from native memory: ” + value);
  •         }
  •     }
  • }
  • 
    
    
    
• JEP 447: Pattern Matching for Switch (Third Preview): Enhanced pattern matching for switch statements.
  • Explanation: Java 22 continues to preview pattern matching for switch statements, providing more flexibility and improving code clarity when handling multiple cases.
  • Importance: This feature simplifies complex switch statements and enhances readability and maintainability.
  • Example:
    
    public class PatternMatchingForSwitchDemo {
  •     public static void main(String[] args) {
  •         Object obj = “Hello”;
  •         String result = switch (obj) {
  •             case Integer i -> “Integer: ” + i;
  •             case String s -> “String: ” + s;
  •             default -> “Other”;
  •         };
  •         System.out.println(result);
  •     }
  • }
  • 
    

Summary

In summary, the Java programming language has undergone significant evolution over the years, with each new version introducing features that enhance its capabilities and address emerging development needs. From its inception, Java has continuously adapted to the changing landscape of software development, incorporating improvements that streamline code writing, optimize performance, and enrich the development experience.

The journey through Java’s versions reveals a pattern of innovation that focuses on making the language more robust, versatile, and developer-friendly. By addressing both foundational concepts and modern requirements, Java remains a powerful and relevant tool for building a wide range of applications. As we look ahead, Java’s commitment to advancement promises to keep it at the forefront of the programming world, driving continued progress and opportunities for developers.

Legend of Acronyms

API – Application Programming Interface

AWT – Abstract Window Toolkit
JDBC – Java Database Connectivity
RMI – Remote Method Invocation
JVM – Java Virtual Machine
CORBA – Common Object Request Broker Architecture
IIOP – Internet Inter-ORB Protocol
JNDI – Java Naming and Directory Interface
NIO – New I/O
JIT – Just-In-Time
JFC – Java Foundation Classes
JAXB – Java Architecture for XML Binding
POJO – Plain Old Java Object
JShell – Java Shell (interactive REPL)
AppCDS – Application Class-Data Sharing
REPL – Read-Eval-Print Loop
javax.script – Java package for scripting support
Rhino – JavaScript engine for Java
XML – Extensible Markup Language
SOAP – Simple Object Access Protocol
RESTful – Representational State Transfer
JAXBContext – Context for JAXB operations
Marshaller – Object to XML conversion tool
AutoCloseable – Interface for resources that need to be closed
Diamond Operator – < > used for generic type inference
NIO.2 – Enhancements to the NIO library
java.time – New Date and Time API
Optional – Container class for optional values
Nashorn – JavaScript engine introduced in Java 8
Project Jigsaw – Modular system for Java applications
Stream API – API for functional-style operations on sequences
Type Annotations – Annotations on type declarations
Module System – Java system for modularizing applications
var – Local-variable type inference keyword introduced in Java 10
Thread-Local Handshakes – JVM feature for improved thread management
CDS – Class Data Sharing
ZGC – Z Garbage Collector
JEP – JDK Enhancement-Proposal
ISO – International Organization for Standardization
JDK – Java Development Kit
HTTP – Hypertext Transfer Protocol
HTTP Client API – API for HTTP communication
HttpURLConnection API – API for HTTP connections
String Methods – Methods for manipulating strings
Local-Variable Syntax for Lambda Parameters – Enhanced syntax for lambda expressions
Flight Recorder – Tool for recording JVM events and profiling
Java EE – Java Platform, Enterprise Edition
CORBA Modules – Modules for CORBA implementation
Switch Expressions – Enhanced switch statements with expression support
JVM Constants API – API for accessing JVM constants
Shenandoah Garbage Collector – Low-latency garbage collector
Microbenchmark Suite – Suite for benchmarking Java code
Text Blocks – Multiline string literals
Dynamic CDS Archives – Dynamic Class Data Sharing
Sealed Classes – Classes with restricted subclassing
Hidden Classes – Classes not accessible by name
Foreign-Memory Access API – API for accessing foreign memory
Unix-Domain Socket Support – Support for Unix domain sockets
Pattern Matching for instanceof – Enhanced pattern matching with instanceof
Records – Immutable data classes
Foreign Function & Memory API – API for interacting with native code and memory
macOS/AArch64 Port – Support for Apple Silicon Macs
Virtual Threads – Lightweight concurrency model
Sequenced Collections – Collections with sequential access
Scoped Values – Values scoped to specific contexts
String Templates – Simplified string formatting
Unnamed Patterns and Variables – Support for unnamed patterns and variables