Java Versions: Comparisons and Examples

Java is a widely recognized programming language renowned for its robustness, scalability, and extensive ecosystem. Over the years, Java has undergone significant advancements and introduced various new features in each major release. This document aims to compare Java 7, which is a widely adopted long-term support (LTS) version, with other Java versions up to the latest release, Java 17. We will delve into the notable enhancements brought by each version and provide illustrative examples to demonstrate the practical usage of these new features in Java. By exploring the differences between the versions, developers can gain valuable insights and make informed decisions when selecting the appropriate Java version for their projects.

Java 7

Java 7 introduced several new features and enhancements.

• String in Switch
  Java 7 introduced the ability to use strings in the switch statement, making code more readable and reducing the need for multiple if-else statements.

• Try-With-Resources
  Try-with-resources simplifies the handling of resources by automatically closing them at the end of the block. It ensures proper resource management and reduces the boilerplate code for opening and closing resources.
  The below example compares how would we read a file before java7 and using java7.

• Improved Type-Reference Operator
  The diamond operator allows type inference for generic classes, making the code more concise by eliminating the need to repeat the generic type declaration.

• Binary Literals
  Java 7 introduced the ability to express integral types (byte, short, int, long) using binary literals, making it easier to work with binary values.

• Improved Exception Handling
  Java 7 introduced multi-catch and improved exception handling by allowing the handling of multiple exceptions in a single catch block.
  In the below example, compare lines 9–13(before java7) and line 24–25(using java7).

These are just a few examples of the features introduced in Java 7.
Note that Java 7 also included other enhancements like improved numeric literals, fork-join framework, and more, that would be hard to cover in a single doc.

Java 8

• Lambda Expressions
  Java 8 introduced lambda expressions, enabling functional programming constructs in Java. Lambda expressions provide a concise way to express anonymous functions and enable the use of functional interfaces.

• Stream API
  Before Java 8, processing collections involved writing manual loops and conditional statements to perform operations like filtering, mapping, and reducing. This approach often resulted in verbose and error-prone code. However, with the introduction of the Stream API in Java 8, working with collections became more streamlined and expressive.

• Optional Class
  Before Java 8, handling null values in Java involved manual checks and conditional statements to avoid NullPointerExceptions. This approach often led to verbose and error-prone code. However, with the introduction of the Optional class in Java 8, developers gained a more concise and safer way to deal with potentially null values.

Java 9

• JShell (Java REPL)
  Before Java 9, developers had to write code in a separate Java class and compile it to see the output. With Java 9, the introduction of JShell allows developers to execute Java code interactively without the need for a separate class or compilation.

• Module System (Project Jigsaw)
  The Module System, also known as Project Jigsaw, was introduced in Java 9 to improve the scalability, maintainability, and security of large Java applications. It provides a way to organize code into modules, which are self-contained units with explicit dependencies.
  Let’s say we have a simple Java application that consists of two modules: com.example.app and com.example.util. The com.example.app module depends on the com.example.util module.

# Directory Structure
app/ 
└── src/     
    ├── com.example.app/     
    │   └── module-info.java     
└── com.example.util/         
    └── module-info.java

// module-info.java in com.example.app module:
module com.example.app {     
  requires com.example.util; 
}

// module-info.java in com.example.util module:
module com.example.util {     
  exports com.example.util; 
}

# Compile the application
javac -d mods/com.example.app src/com.example.app/module-info.java src/com.example.app/com/example/app/Main.java javac -d mods/com.example.util src/com.example.util/module-info.java src/com.example.util/com/example/util/UtilClass.javajavac -d mods/com.example.app src/com.example.app/module-info.java src/com.example.app/com/example/app/Main.java javac -d mods/com.example.util src/com.example.util/module-info.java src/com.example.util/com/example/util/UtilClass.java

# Run the application
java --module-path mods --module com.example.app/com.example.app.Main

In this example, the module-info.java files define the module declarations for each module. The requires statement in the com.example.app module specifies that it depends on the com.example.util module. The exports statement in the com.example.util module exports the com.example.util package, making it accessible to other modules.

By using the Module System, we can enforce encapsulation and control the visibility of classes and packages between modules. It helps to avoid classpath conflicts, improve security by limiting access to internal APIs, and optimize the application’s startup time by only loading required modules.

Private Methods in Interfaces
Before Java 9, all methods in an interface were implicitly public. Java 9 introduced the ability to define private methods in interfaces, which can be used to reduce code duplication and improve code organization.

• HTTP/2 Client API
  The HTTP/2 Client API was introduced in Java 9 as a new standard API for performing HTTP communication in Java applications. It provides a more efficient and modern way to interact with HTTP-based services compared to the older HttpURLConnection API available in Java 8.

In the Java 8 example, we use the HttpURLConnection class to establish a connection, set the request method, read the response, and handle the connection manually.

In the Java 9 example, we utilize the new HTTP/2 Client API provided by the java.net.http package. We create an instance of HttpClient, build an HTTP request using HttpRequest.newBuilder(), and send the request using httpClient.send(). The response is received as an HttpResponse object, and we extract the response body using the body() method.

• Process API
  The Process API in Java provides a way to interact with operating system processes from within a Java application. It allows you to start new processes, manage them, and communicate with them. In Java 8, the Process API had limited functionality, while Java 9 introduced several enhancements to make it more powerful and flexible.

• These are just a few examples of the new features introduced in Java 9. Other notable features include the HTTP/2 Client API, improved process API, and more. Java 9 brought significant improvements and additional functionality to the Java platform, making it easier and more efficient to develop Java applications.

Java 10

• Local Variable Type Inference
  Before Java 10, developers had to explicitly declare the types of variables. With the introduction of local variable type inference, Java 10 allows the type of a variable to be inferred from the assignment statement. This reduces boilerplate code and improves readability.

• Application Class-Data Sharing
  Java 10 introduced Application Class-Data Sharing, which allows classes and data to be pre-processed and shared among multiple Java Virtual Machine (JVM) instances. This feature improves startup time and reduces memory footprint by avoiding redundant class loading. It can be achieved using the java -Xshare:dump and java -Xshare:on commands.
• Garbage-Collector Interface
  Prior to Java 10, adding a new garbage collector required modifying the Java Virtual Machine (JVM) itself. This made it challenging for developers to experiment with different garbage collection techniques and limited their ability to optimize memory management for specific use cases. The Garbage Collector Interface in Java 10 addresses these limitations by providing a standardized way to develop and integrate custom garbage collectors.
  To implement a custom garbage collector using the Garbage Collector Interface, the following steps need to be followed:
  a. Implement the Collector interface: Create a class that implements the java.util.stream.Collector interface. This interface defines the methods required for garbage collection, such as collect(), combine(), and finish().
  b. Register the Collector: Register the custom collector using the java.util.stream.CollectorRegistry class. This class provides methods to register and access custom collectors.
  c. Enable the Custom Garbage Collector: Enable the custom garbage collector by setting the appropriate JVM options. This can be done using the -XX:+Use flag followed by the name of the custom collector.

In the above example, we define a CustomGarbageCollector class that implements the Collector interface. We register this custom collector using the CollectorRegistry class and enable it by setting the java.util.stream.useCustomGC system property to the name of the custom collector.

• Time-Based Release Versioning
  Java 10 introduced a new versioning scheme called time-based release versioning. Instead of fixed release schedules, Java versions are now released every 6 months. This enables faster delivery of new features, bug fixes, and improvements to the Java platform.
• Improved Optional Class
  Java 10 added several enhancements to the Optional class, making it more useful and convenient to work with. Some of the improvements include the orElseThrow() method, which throws an exception if the optional value is not present, and the stream() method, which allows optional values to be processed as streams.

• Process API improvements
  In Java 10, the Process API introduced the following methods that were not present in Java 9:
  isAlive(): This method returns a boolean value indicating whether the process is still running or has terminated.
  onExit(): This method returns a CompletableFuture<Process> that can be used to perform actions asynchronously when the process exits.
  toHandle(): This method returns a ProcessHandle object representing the process. The ProcessHandle class provides various methods to interact with and obtain information about the process.
• Enhancements to CompletableFuture API
  In Java 10, the CompletableFuture API introduced several enhancements that were not present in Java 9. These enhancements include:
  1. completeAsync() and completeOnTimeout(): These methods allow you to complete a CompletableFuture asynchronously using a Supplier or with a default value if a timeout occurs.
  2. orTimeout(): This method allows you to specify a timeout duration for a CompletableFuture, after which it will complete exceptionally with a TimeoutException.
  3. copy(): This method creates a new CompletableFuture with the same completion state and result as the original CompletableFuture.
  4. completeAsync() variants with an Executor: These variants allow you to specify an Executor on which the asynchronous computation should be performed.
  5. newIncompleteFuture(): This static factory method creates a new incomplete CompletableFuture.
• Optimizing the G1 garbage collectors
  In Java 10, the G1 (Garbage-First) garbage collector received several improvements aimed at enhancing its performance compared to Java 9. These improvements included:
  1. Concurrent Full GC: Java 10 introduced enhancements to the G1 garbage collector that reduced the duration of Full GC pauses by enabling more work to be performed concurrently with the garbage collection cycle. This improvement resulted in reduced application pauses and improved overall throughput.
  2. Heap Region Uncommit: Java 10 introduced the ability for the G1 garbage collector to dynamically uncommit empty heap regions, freeing up memory and improving the efficiency of memory usage. This feature helped in reducing the footprint of the garbage collector and allowing applications to make more efficient use of available memory.
  3. Thread-Local Handshakes: Java 10 introduced thread-local handshakes as a mechanism to improve the coordination between the G1 garbage collector and application threads. This allowed the garbage collector to better understand the state of application threads, leading to improved performance and reduced overhead.
  - These performance enhancements in Java 10 for the G1 garbage collector aimed to improve both the pause times and overall throughput of garbage collection operations. The introduction of concurrent full GC, heap region uncommit, and thread-local handshakes helped in optimizing the G1 garbage collector’s behavior and improving its efficiency in handling garbage collection tasks.

Java 11

• Local Variable Syntax for Lambda Parameters
  Before Java 11, lambda parameters required explicit type declarations. With Java 11, the syntax has been simplified, allowing the use of var for lambda parameters.

• HTTP Client API
  Java 11 includes a new, standardized HTTP Client API that supports both synchronous and asynchronous operations. It provides a modern alternative to the legacy HttpURLConnection API.
  Below is an example of making a GET request using the new HTTP Client API:

• Nest-Based Access Control
  Java 11 introduces nest-based access control, allowing access to private members of a nested class from its enclosing class and other nested classes within the same nest. This feature improves encapsulation and enables better organization of related classes.

• Epsilon Garbage Collector
  Epsilon is a no-op garbage collector. Unlike other garbage collectors that manage memory and reclaim unused objects, the Epsilon collector simply allocates memory without performing any garbage collection. This makes it suitable for scenarios where memory management is not a concern, such as performance testing or short-lived applications.
  By enabling the Epsilon garbage collector, the JVM will allocate memory without performing any garbage collection, resulting in minimal pause times. This can be useful when testing the performance characteristics of an application without the overhead of garbage collection.

• Deprecation of APIs
  Removal of deprecated APIs to improve code cleanliness and maintainability.
  1. java.xml.ws package: This package, which provided the API for Java API for XML Web Services (JAX-WS), was deprecated in Java 9 and removed in Java 11. It was replaced by the more modern and standard JAX-WS implementation available in the Java SE Platform.
  2. java.xml.bind module: The Java Architecture for XML Binding (JAXB) API, which was part of the java.xml.bind module, was deprecated in Java 9 and removed in Java 11. JAXB is still available as a separate module and can be included as a dependency if needed.
  3. java.management.jmxremote* properties: The JMX remote monitoring and management properties, such as com.sun.management.jmxremote.port, com.sun.management.jmxremote.authenticate, and com.sun.management.jmxremote.ssl, were deprecated in Java 9 and removed in Java 11. These properties were part of the proprietary JMX implementation and have been replaced by a more standardized and secure approach to JMX remote management.
  4. java.corba module: The CORBA (Common Object Request Broker Architecture) module, which provided support for distributed object communication, was deprecated in Java 9 and removed in Java 11. CORBA is still available as a separate module and can be used if required.
  5. Various other deprecated classes and methods: Java 11 also removed various deprecated classes, methods, and constants from different packages and modules. These deprecations were identified to have better alternatives or were considered outdated or unnecessary. Examples: java.io.FileInputStream(FileDescriptor): This constructor in the FileInputStream class, deprecated in Java 9, was removed in Java 11. Some more examples:
  Example 1: java.util.Vector: The Vector class, a synchronized collection class, was deprecated in earlier versions and removed in Java 11. It has been replaced by the more efficient and modern ArrayList or LinkedList classes.
  Example 2: java.util.Stack: The Stack class, another synchronized collection class that extends Vector, was also deprecated and removed in Java 11. It is recommended to use the Deque interface or LinkedList class instead.
  Example 3: java.util.Dictionary: The Dictionary class, which served as an abstract class for key-value mappings, was deprecated and removed in Java 11. It has been replaced by the Map interface and its implementations such as HashMap or Hashtable.
  Example 4: java.util.Hashtable: The Hashtable class, a synchronized implementation of the Map interface, was deprecated and removed in Java 11. It is recommended to use HashMap or ConcurrentHashMap instead.
  Example 5: java.util.Observable and java.util.Observer: These classes, used for implementing the observer design pattern, were deprecated and removed in Java 11. It is now suggested to use the java.util.concurrent.Flow API or third-party libraries like ReactiveX for reactive programming.

Java 12

• Switch Expressions
  Before Java 12, the switch statement was limited to using constant values. In Java 12, switch expressions were introduced, allowing the use of both constant and non-constant values.

• Compact Number Formatting
  Java 12 introduces the CompactNumberFormat class, which provides a compact representation of numbers by replacing the repeated groups of zeros with a short symbol.

• Teeing Collector
  Java 12 introduces a new collector, teeing(), which combines two collectors and applies a combining function to their results. This allows for more efficient and concise stream processing.

The teeing collector simplifies the calculation of combined results from two collectors, eliminating the need for intermediate variables.

• Shenandoah garbage collector
  Shenandoah garbage collector is an experimental garbage collector that focuses on achieving low-pause time for applications. It aims to reduce the impact of garbage collection pauses on application responsiveness and throughput.

• Improvements to the G1 Garbage Collector
  Java 12 includes enhancements to the G1 (Garbage-First) garbage collector to improve its performance and stability. The G1 garbage collector is a concurrent garbage collector that aims to provide high throughput while keeping the garbage collection pauses within certain latency goals.

Java 13

• Switch Expressions
  The switch expression in Java 13 allows the use of lambda-style arrows (->) to define the case values. This simplifies the syntax and makes the code more concise.

• Text Blocks (Preview Feature — Officially released in java 14)
  Text blocks in Java 13 provide a convenient way to define multiline strings without the need for concatenation or escape characters. They preserve the formatting and indentation, making it easier to write and read HTML, SQL queries, JSON, and other structured text.

• Enhanced NullPointerException Messages
  Java 13 provides improved NullPointerException messages by including additional details such as the name of the variable or expression that caused the exception. This helps developers identify the source of the null value more easily.

• Dynamic CDS Archives
  Java 13 introduced the concept of Dynamic Class-Data Sharing (CDS) archives, which allows the runtime to dynamically load classes from a shared archive file. This improves startup time and reduces memory footprint.

Java 14

• Switch Expressions (Preview)
  Java 14 introduced a preview feature that extends the switch expressions introduced in Java 13. It enhances the syntax by introducing multiple labels in a single case block and allowing the yield keyword to explicitly return a value from the switch expression.

These enhancements in switch statements provide more flexibility and readability, making the code more concise and expressive. It is important to note that the Java 14 switch expression feature is a preview feature, which means it is not enabled by default and requires the use of --enable-preview flag during compilation and execution.

• Records
  Java 14 introduced records, which are a new kind of class specifically designed for immutable data models. Records provide a concise syntax for defining classes whose main purpose is to store data.

• Pattern Matching for instanceof
  Java 14 introduced pattern matching for the instanceof operator as a preview feature. It allows developers to simplify the common use case of casting an object and performing operations based on its type.

• Text Blocks
  Java 14 introduced text blocks as a standard feature to improve the readability of multi-line string literals. Before Java 14, multi-line strings had to be concatenated using the + operator. With text blocks, you can write multi-line strings in a more natural and readable way.

Java 13 text blocks allowed preserving indentation by removing common leading whitespaces from each line, making the code more readable. However, there were limitations in handling the trailing whitespaces and the presence of escape sequences.

• Helpful NullPointerExceptions
  In Java 13, a new feature called “Helpful NullPointerExceptions” was introduced. It aimed to improve the NPE error messages by providing additional details about the source of the exception. Java 14 further enhanced the NPE messages.
  Example of NPE message in Java 13:

Exception in thread "main" java.lang.NullPointerException: Cannot invoke "String.length()" because "str" is null
	at MainClass.main(MainClass.java:6)

The Java 13 NPE message clearly indicates that the exception occurred because the length() method was invoked on a null reference variable str.

Java 14 further enhanced the NPE messages introduced in Java 13 by providing even more helpful information.

Exception in thread "main" java.lang.NullPointerException: Cannot invoke "String.length()" on null object
	at MainClass.main(MainClass.java:6)

The Java 14 NPE message includes additional information by explicitly stating that the null object caused the exception, making it easier to identify the root cause.

Java 15

• Text Blocks
  Java 13: Introduced text blocks as a preview feature, providing a cleaner way to represent multiline strings.
  Java 14: Made text blocks a standard feature and removed leading whitespace indentation.
  Java 15: Enhanced text blocks with support for escape sequences and expressions, making them more flexible and dynamic.
  Java 15 introduced a few improvements to text blocks, making them even more powerful and flexible. It added support for escape sequences and expressions within text blocks. This allows developers to include special characters or dynamically insert values into the multiline strings.

• Sealed Classes
  In prior versions of Java, classes could be extended by any other class. However, in Java 15, the sealed classes feature allows developers to restrict which classes can be subclasses. This improves code encapsulation and prevents unauthorized inheritance.

• Records
  Java 14: In Java 14, records are primarily focused on data storage and do not support additional behaviors.
  Java 15: Java 15 added limited support for additional behaviors in records, allowing you to declare instance methods and static methods within the record body.

• Pattern Matching for instanceof
  Pattern Matching for instanceof is a feature introduced in Java 14 and further enhanced in Java 15. It allows developers to simplify the common use case of type-checking and casting in Java code.
  Java 14: In Java 14, the Pattern Matching for instanceof feature was introduced with limited functionality. It allows you to declare a new variable within an if statement and use it for further processing if the instanceof check is successful.
  Java 15: Java 15 introduced enhancements to the Pattern Matching for instanceof feature, providing additional capabilities and flexibility.

In Java 15, you can combine the instanceof check with an additional condition using the logical AND operator (&&). This allows you to perform more complex checks on the object and use the variable within the if block.
It’s important to note that the variable str is effectively final within the if block. This means you cannot reassign it or modify its value.

• Hidden Classes
  Java 15 introduced hidden classes, which are classes that are not discoverable by reflection. Hidden classes improve security and performance by encapsulating internal implementation details.
  Java 15 introduced hidden classes, which are classes that are not discoverable by reflection. Hidden classes improve security and performance by encapsulating internal implementation details.
  Here’s an example:

// Before Java 15
// Code using reflection to access internal classes

// Java 15
// Hidden classes are not discoverable by reflection

Java 16

• Unix-Domain Socket Channels
  Before Java 16, there was no built-in support for Unix-Domain Socket Channels in the Java programming language. Unix-Domain Socket Channels are a type of socket that enables inter-process communication (IPC) within the same host, without the overhead of network communication.
  Prior to Java 16, developers had to rely on external libraries or implement custom solutions to establish Unix-Domain Socket connections and handle IPC. This added complexity and made the code less portable across different platforms.
  However, with the introduction of Java 16, native support for Unix-Domain Socket Channels was added to the Java standard library. This made it much easier for developers to work with Unix-Domain Sockets and simplified the implementation of IPC-based applications.

• Foreign Function & Memory API
  Before Java 16, there was no built-in support for interacting with native code and managing native memory within the Java programming language. Developers had to rely on external libraries or use complex and error-prone mechanisms like Java Native Interface (JNI) to integrate native code with their Java applications.
  However, with the introduction of the Foreign Function & Memory API in Java 16, developers now have a standardized and safer way to interact with native code and manage native memory directly within the Java language. The Foreign Function & Memory API provides a set of interfaces and classes that enable Java code to call native functions and allocate, access, and free native memory.

In the example above, before Java 16, we relied on the JNA (Java Native Access) library to interact with native code. We defined a native library interface that extends the com.sun.jna.Library interface and provides the necessary native method declaration. We then loaded the native library using the Native.load() method and called the native method using the interface instance.

In the example above, with Java 16, we can use the Foreign Function & Memory API directly within the Java language. We allocate native memory using the CLinker.allocateMemory() method, which returns a MemoryAddress representing the allocated memory. We can then access and manipulate the native memory using the MemoryAddress object. Additionally, we can call native functions using the CLinker.C_POINTER.call() method. Finally, we free the native memory using the CLinker.free() method.

• Improved Pseudo-Random Number Generators
  Java 16 introduces an improved implementation of Pseudo-Random Number Generators (PRNG). Now, we can create an instance of Random and generate random numbers more conveniently in a single line of code.

• In Java 16, the usage of sealed classes remains the same as in Java 15. However, the improvement lies in the handling of unintentional violations of the sealed class contract. In Java 16, the Triangle class is not declared as a subclass of Shape, and it remains unrelated. This improvement provides better control and prevents accidental violations of the sealed class contract.
• Sealed Class
  The usage of sealed classes in Java 15 and Java
  16 is similar. The main enhancement in Java 16 is the prevention of unintended violations of the sealed class contract, ensuring that only authorized subclasses are allowed to extend or implement a sealed class. This improvement helps maintain the integrity and control of the sealed class hierarchy.

In Java 15, sealed classes are declared using the sealed keyword, and the permits clause specifies the subclasses that are allowed to extend or implement the sealed class. In this example, the Shape class is sealed, and it permits two subclasses, Circle and Square. Additionally, we can see that the Triangle class is mistakenly declared as a subclass of Shape, even though it is not permitted. This is an unintended violation of the sealed class contract in Java 15.

In Java 16, the usage of sealed classes remains the same as in Java 15. However, the improvement lies in the handling of unintentional violations of the sealed class contract. In Java 16, the Triangle class is not declared as a subclass of Shape, and it remains unrelated. This improvement provides better control and prevents accidental violations of the sealed class contract.

• Pattern Matching for instanceof
  Pattern Matching for instanceof was introduced as a preview feature in Java 14 and continued to evolve in Java 15 and Java 16. Let’s compare its usage in Java 15 and Java 16 with an example:

In Java 15, when using instanceof to check the type of an object, we need to cast the object to the desired type before accessing its specific members or invoking methods. This can be seen in the example above, where we check if the shape object is an instance of Circle and then explicitly cast it to Circle to calculate the area.

In Java 16, the pattern matching for instanceof feature has been enhanced, allowing for a more concise and expressive code. Instead of using a separate cast statement, we can declare a new variable (circle in this case) directly in the instanceof condition. This variable is then scoped to the if block and represents the casted object of the specified type. This improvement eliminates the need for a separate cast statement, making the code more readable and reducing the chances of potential errors.

Java 17

• Sealed Classes
  In Java 17, sealed classes have received additional enhancements. One notable improvement is the ability to declare a single default implementation for all permitted subclasses using the default keyword.

• Pattern Matching for Switch
  Pattern Matching for Switch is a feature introduced in Java 16 and enhanced in Java 17, allowing for more concise and expressive code when working with switch statements.
  In Java 16, Pattern Matching for Switch allows you to combine the matching and assignment of a value in a single line of code.
  Here’s an example:

In this example, the switch statement uses the -> operator to both match the value of animal and assign it to a new variable (d, c, or b) specific to the matched case. This eliminates the need for explicit variable declaration and separate assignment statements.

In Java 17, Pattern Matching for Switch has been enhanced to support patterns with additional conditions using the when keyword.
Here's an example:

In Java 17, the when keyword is introduced to add additional conditions to the patterns. This allows for more fine-grained control over the matching behavior and enables the execution of specific code based on additional criteria.

• Strong Encapsulation of JDK Internals
  Prior to Java 17, there was limited encapsulation of internal JDK APIs, which allowed developers to access and use them directly. However, in Java 17, the encapsulation of these internal APIs is strengthened to discourage their direct usage and promote better code modularization.

In previous versions of Java, this code would compile and run without any issues. However, in Java 17, the strong encapsulation of internal APIs prevents direct access to the sun.misc.BASE64Encoder class. As a result, attempting to compile this code in Java 17 would result in a compilation error, indicating that the class is not accessible.

By strengthening the encapsulation of internal APIs, Java 17 encourages developers to rely on supported and documented APIs instead. In this case, developers are encouraged to use the java.util.Base64 class, which provides a standard way to encode and decode data using Base64 encoding:

In this updated code, the java.util.Base64 class is used instead of the internal sun.misc.BASE64Encoder. This ensures compatibility and maintainability of the code across different Java versions, as the Base64 class is part of the public API and is guaranteed to be supported.

• Enhanced Foreign Function & Memory API (Incubator)
  The Enhanced Foreign Function & Memory API (Incubator) is an experimental feature introduced in Java 16 and further enhanced in Java 17. While the core functionality remains the same as in Java 16, several enhancements and refinements have been made. Here is one such example where MemorySegment is allocated using the allocateNative() method, just like in Java 16. However, Java 17 introduces automatic resource management using the try-with-resources statement. By enclosing the MemorySegment creation within the try-with-resources block, we ensure proper deallocation of native memory resources, even in case of exceptions.

• Enhanced Support for Deprecation
  Java 17 introduces additional improvements to the deprecation process. It provides a new forRemoval flag that indicates whether a deprecated API will be removed in a future version. This helps developers better understand the deprecation status and plan for future updates.

In this example, the deprecatedMethod() in the DeprecatedApi class is marked with the @Deprecated(forRemoval = true) annotation. This annotation indicates that the method is deprecated and will be removed in a future version of Java. The forRemoval flag explicitly specifies the intention to remove the method.

When compiling the code in Java 17, the usage of deprecatedMethod() will generate a deprecation warning. This warning serves as a notice to developers that the method they are using is deprecated and should not be relied upon in new code. It also serves as a reminder to update existing code that still uses the deprecated method.

The forRemoval flag in Java 17 helps developers understand the deprecation status of an API and provides a clear indication that the marked element will be removed in a future release. This encourages developers to find alternative solutions and update their code accordingly, ensuring compatibility with future Java versions.

It’s important for developers to review their code, identify any usage of deprecated elements with the forRemoval flag, and replace them with recommended alternatives or newer APIs. This helps maintain code quality, prevents reliance on deprecated features, and ensures smoother transitions during future upgrades.

In conclusion, Java has undergone significant advancements and introduced numerous features from Java 7 to Java 17. Each version has brought enhancements to the language, libraries, and tools, providing developers with powerful capabilities to build robust and efficient applications. Here’s a brief summary of the major features introduced in each version:

• Java 7: Features like try-with-resources, binary literals, and improved exception handling brought improved resource management, code readability, and flexibility.
• Java 8: The introduction of lambda expressions, functional interfaces, and the Stream API revolutionized Java’s programming paradigm, enabling functional programming styles and streamlining data processing operations.
• Java 9: Module system (Project Jigsaw) introduced modularity to the Java platform, enhancing code organization, encapsulation, and scalability. It also included features like the JShell REPL and various enhancements to the collections framework.
• Java 10: Introduced features like local variable type inference (var keyword) and the experimental garbage collector (Epsilon), enhancing code conciseness and providing performance testing capabilities.
• Java 11: Focused on improving developer productivity with features like local variable syntax for lambda parameters, HTTP client API, and various performance improvements. It also marked the transition to a rapid release model.
• Java 12: Brought features like switch expressions and compact number formatting, improving code expressiveness and localization capabilities.
• Java 13: Introduced features like text blocks (preview feature), improved the switch statement, and provided enhancements to the garbage collector and the String class.
• Java 14: Major features included records, pattern matching for instanceof, and improved NullPointerException messages. These features promoted code conciseness, pattern matching capabilities, and enhanced developer productivity.
• Java 15: Features like sealed classes, hidden classes, and improved garbage collection algorithms provided better code encapsulation, security, and performance optimization.
• Java 16: Introduced features like Unix-Domain Socket Channels, Foreign Function & Memory API enhancements, and improved sealed classes. These features enhanced networking capabilities, provided better interoperability with native code, and promoted code modularity.
• Java 17: Features like enhanced Foreign Function & Memory API (incubator), improved support for deprecation, forRemoval flag for strong encapsulation of JDK internals, and enhanced pattern matching for switch statements. These features enhanced native code integration, deprecated API handling, and encapsulation of internal JDK APIs.

These versions have collectively transformed the Java ecosystem and empowered developers to build sophisticated, scalable, and maintainable applications. It’s important for developers to stay up-to-date with the latest Java versions and leverage the features and improvements they offer to enhance their productivity and deliver high-quality software solutions.