Java 17
Java 17 LTS is the latest long-term support release for the Java SE platform. JDK 17 binaries are free to use in production and free to redistribute, at no cost, under the Oracle No-Fee Terms and Conditions License, where LTS stands for long-term support. It was released on September 15, 2021.
1. What are the new features introduced in Java 17?
Yes everybody is crazy for major updates in this version in order to transduce workflow but developers should be disappointed as there are not such big release update version checks as we can see from the JDK enhancement proposal commonly referred to as JEPS as provided below:
- 306: Restore Always-Strict Floating-Point Semantics
- 356: Enhanced pseudo-Random Number Generators
- 382: New macOS Rendering pipelines
- 398: Deprecate the Applet API for Removal
- 403: Strongly Encapsulated JDK Internals
- 406: Pattern matching for Switch(Preview)
- 407: Removal RMI Activation
- 409: Sealed Classes
- 410: Removal Experimental AOT and JIT Compiler
- 411: Deprecate the Security manager for Removal
- 412: Foreign Functions & memory API(Incubator)
- 414: Vector API(Second Incubator)
- 415: Context-Specific Deserialization Filters
JEP 306: Restore Always-Strict Floating-Point Semantics
Floating-point numbers in Java, such as float and double, are used to represent real numbers with a fractional part. However, performing calculations with floating-point numbers can sometimes lead to small discrepancies due to the inherent limitations of representing real numbers in a finite amount of memory. JEP 306 aims to address these inconsistencies and improve the accuracy of floating-point calculations in Java.
Understanding Floating-Point Arithmetic
Floating-point numbers are not exact representations of real numbers due to limited memory. As a result, calculations involving floating-point numbers may have small rounding errors. For example, when adding 0.1 and 0.2, we might expect the result to be 0.3, but due to these rounding errors, the actual result might be slightly different.
1double result = 0.1 + 0.2;
2System.out.println(result);
The output of the above code might be 0.30000000000000004, which is a slight deviation from the expected result.
The Issue: Inconsistencies in Floating-Point Semantics
In previous versions of Java, the default floating-point semantics allowed for some flexibility in rounding and precision. While this flexibility improved performance, it could result in inconsistencies when performing calculations. For example:
1double a = 1.0;
2double b = 0.9;
3double c = 0.1;
4double result = a - b;
5if (result == c) {
6 System.out.println("Equal");
7} else {
8 System.out.println("Not Equal");
9}
In previous versions of Java, the output of the above code would be Equal, even though we might intuitively expect it to be Not Equal. This inconsistency arises due to the flexible rounding and precision used in floating-point arithmetic.
The Solution: Always-Strict Floating-Point Semantics
JEP 306, introduced in Java 17, restores always-strict floating-point semantics by making changes to the underlying floating-point operations. This means that floating-point calculations now adhere to stricter rules, leading to more consistent and predictable results.
To demonstrate this, let’s revisit the previous example:
1double a = 1.0;
2double b = 0.9;
3double c = 0.1;
4double result = a - b;
5if (result == c) {
6 System.out.println("Equal");
7} else {
8 System.out.println("Not Equal");
9}
In Java 17, the output of the above code will be Not Equal, as expected. The stricter floating-point semantics ensure that the rounding and precision of calculations are consistent, eliminating unexpected behavior.
Considerations for Existing Code
While the change to always-strict floating-point semantics in Java 17 is generally beneficial, it’s important to note that it may lead to differences in behavior compared to previous versions of Java. Existing code that relies on the previous, more flexible floating-point semantics might need to be reviewed and modified accordingly.
Developers should carefully test and validate their code when migrating to Java 17 to ensure that the changes in floating-point behavior do not introduce any unforeseen issues.
Conclusion
JEP 306: Restore Always-Strict Floating-Point Semantics in Java 17 addresses inconsistencies in floating-point arithmetic and improves the accuracy and predictability of calculations. The change ensures that floating-point operations adhere to stricter rules, leading to more consistent results. It’s important to be aware of these changes when migrating existing code to Java 17.
Exploring Java 17: New macOS Rendering Pipelines
In the world of Java programming, rendering pipelines play a crucial role in displaying graphics and user interfaces. With the release of Java 17, a significant improvement has been introduced for macOS users with JEP 382, which focuses on new rendering pipelines for macOS.
Understanding Rendering Pipelines
Rendering pipelines are responsible for rendering and displaying graphics on the screen. They handle tasks such as rendering shapes, text, images, and user interface components. Different operating systems may have their own rendering pipelines optimized for their specific graphical environments.
The Need for New macOS Rendering Pipelines
In the case of macOS, the existing rendering pipelines used by Java applications were based on the deprecated Cocoa API, which had limitations and performance issues. JEP 382 addresses this by introducing new rendering pipelines for macOS based on the more modern and efficient Metal API.
The new rendering pipelines provide several benefits, including improved performance, better integration with macOS graphical environments, and enhanced compatibility with the latest macOS versions.
Example: Improved Graphics Rendering on macOS
To illustrate the impact of the new macOS rendering pipelines, let’s consider an example where a Java application displays a complex graphical user interface (GUI) on a macOS system.
In previous Java versions, the rendering of the GUI components on macOS might have been slower or less smooth due to the limitations of the old rendering pipelines. With the introduction of JEP 382, the new rendering pipelines based on Metal API offer improved performance and graphical rendering capabilities.
As a result, the same Java application running on Java 17 with the new macOS rendering pipelines will provide a smoother and more responsive user interface experience on macOS systems. Graphics, animations, and transitions will be rendered more efficiently, contributing to an overall enhanced user experience.
Conclusion
JEP 382: New macOS Rendering Pipelines brings significant improvements to Java applications running on macOS systems. By replacing the older rendering pipelines with new ones based on the Metal API, Java 17 provides better performance, improved graphical rendering, and enhanced compatibility with the latest macOS versions.
JEP 356: Enhanced pseudo-Random Number Generators
Introduction
In programming, generating random numbers is often required for various applications. Java provides built-in support for generating random numbers through the java.util.Random class. However, the default random number generator in previous versions of Java had limitations in terms of randomness and flexibility. JEP 356 introduces enhancements to the pseudo-random number generators in Java 17, improving their quality and expanding their capabilities.
Understanding Pseudo-Random Number Generators
Pseudo-random number generators (PRNGs) are algorithms used to generate a sequence of numbers that approximate randomness. PRNGs produce a deterministic sequence of numbers based on an initial seed value. While the generated numbers are not truly random, they exhibit properties that make them suitable for many applications.
The Issue: Limitations of the Default Random Number Generator
The default random number generator in previous versions of Java had limitations in terms of the quality of generated random numbers and the flexibility to customize the generation process. This made it less suitable for certain use cases, such as cryptography or scientific simulations, where higher quality randomness is required.
The Solution: Enhanced pseudo-Random Number Generators
With JEP 356, Java 17 introduces enhanced pseudo-random number generators that offer improved quality and greater flexibility. These enhancements include new algorithms and methods to generate random numbers, as well as the ability to create custom random number generators.
Example Usage: Generating Random Integers
Let’s look at an example that demonstrates generating random integers using the enhanced PRNGs in Java 17:
1import java.util.Random;
2
3public class RandomExample {
4 public static void main(String[] args) {
5 Random random = new Random();
6 int randomNumber = random.nextInt(100);
7 System.out.println("Random Number: " + randomNumber);
8 }
9}
In the above code, we create an instance of the Random class, which is an implementation of the enhanced pseudo-random number generator. We then use the nextInt(int bound) method to generate a random integer between 0 (inclusive) and the specified bound (exclusive). In this case, the bound is 100, so the generated random number will be between 0 and 99.
Customization and Control
In addition to the default random number generator, Java 17 provides new APIs that allow developers to create custom random number generators and have more control over the generation process. This enables developers to tailor the randomness to specific requirements or use alternative algorithms for specialized use cases.
Conclusion
JEP 356: Enhanced pseudo-Random Number Generators in Java 17 introduces improvements to the random number generation capabilities. The enhanced pseudo-random number generators offer better quality randomness and increased flexibility, making them suitable for a wider range of applications. Developers can take advantage of these enhancements to generate random numbers more effectively and customize the generation process according to their specific needs.
Exploring Java 17: Deprecating the Applet API
With the release of Java 17, a significant change has been introduced with JEP 398, which focuses on deprecating the Applet API. This change acknowledges the declining usage and security concerns associated with the Applet API, paving the way for its eventual removal from the Java platform.
Understanding the Applet API
The Applet API has been part of Java since its early days and was used to develop applets, which were small Java programs embedded in web pages. Applets allowed developers to create interactive content on webpages and run them within web browsers. However, with advancements in web technologies and security concerns, the usage of applets has significantly decreased over the years.
Why Deprecate the Applet API?
The decision to deprecate the Applet API is based on several factors:
Security Concerns: Applets have been associated with security vulnerabilities, making them potential targets for malicious attacks. The Applet API’s design and limitations have made it challenging to maintain a secure environment for running applets.
Obsolete Technology: Over time, web technologies such as HTML5, CSS, and JavaScript have evolved significantly, providing more powerful and secure ways to create interactive web content. These technologies have largely replaced the need for applets, making the Applet API less relevant in modern web development.
Decreased Usage: The usage of applets has declined significantly in recent years, with most modern web browsers discontinuing support for Java applets altogether. Developers have shifted to alternative solutions and technologies for creating web-based interactive content.
Impact on Existing Code
The deprecation of the Applet API will primarily impact existing codebases that rely on the Applet API for running applets within web browsers. If you have code that uses the Applet API, it is recommended to migrate to alternative solutions such as JavaFX, HTML5, or other web technologies, depending on your specific requirements.
Example: Migrating from Applet to JavaFX
To help you understand the migration process, let’s consider an example where an applet is used to display a simple message. We’ll showcase how you can migrate this functionality to JavaFX, a popular framework for building rich desktop and web applications.
Here’s a basic example of an applet:
1import java.applet.Applet;
2import java.awt.Graphics;
3
4public class MessageApplet extends Applet {
5 public void paint(Graphics g) {
6 g.drawString("Hello, World!", 20, 20);
7 }
8}
To migrate this functionality to JavaFX, you can use the following code:
1import javafx.application.Application;
2import javafx.scene.Scene;
3import javafx.scene.control.Label;
4import javafx.scene.layout.StackPane;
5import javafx.stage.Stage;
6
7public class MessageJavaFX extends Application {
8 public void start(Stage stage) {
9 Label label = new Label("Hello, World!");
10 StackPane root = new StackPane(label);
11 Scene scene = new Scene(root, 200, 100);
12 stage.setScene(scene);
13 stage.show();
14 }
15
16 public static void main(String[] args) {
17 launch(args);
18 }
19}
In the JavaFX code, we create a simple JavaFX application that displays a label with the message “Hello, World!” on a window. JavaFX provides a more modern and powerful approach to building interactive user interfaces, making it a suitable replacement for applets.
Conclusion
With JEP 398, Java 17 deprecates the Applet API, acknowledging its declining usage and security concerns. The deprecation signals the eventual removal of the Applet API from future versions of Java.
If you have existing code that relies on the Applet API, it’s important to consider migrating to alternative solutions such as JavaFX or other web technologies. Embrace modern web technologies and frameworks to create interactive content that aligns with the evolving web landscape and ensures a secure and robust user experience.
JEP 403 - Strongly Encapsulated JDK Internals
Java 17 introduces a significant enhancement in terms of encapsulation with JEP 403. This new feature, known as “Strongly Encapsulated JDK Internals,” aims to improve security and maintainability by further restricting access to internal implementation details of the Java Development Kit (JDK). In this article, we’ll explore the concept behind this feature and its benefits.
Understanding the Need for Strong Encapsulation
In the Java language, encapsulation is a key principle that promotes modularity, code reusability, and abstraction. It involves hiding implementation details and exposing only necessary interfaces. However, prior to Java 17, some internal JDK classes and APIs were accessible by developers, even though they were not intended for direct use.
This limited encapsulation created several issues:
Security Concerns: Direct access to internal JDK classes could lead to security vulnerabilities, as developers might inadvertently bypass security mechanisms or misuse privileged operations.
Maintainability Challenges: Internal JDK classes are subject to change between JDK releases. When developers rely on these internal classes, their code becomes tightly coupled with specific JDK versions, making it difficult to maintain and update in the future.
JEP 403: Strongly Encapsulated JDK Internals
JEP 403 addresses the issues mentioned above by imposing stricter encapsulation on JDK internals. It achieves this by applying a set of access restrictions to internal JDK classes, preventing direct access by external code.
To understand the impact of this feature, let’s consider a simple example. Suppose you were using the sun.misc.BASE64Encoder class to encode data in previous JDK versions. However, this class is an internal JDK class and should not be used directly. In Java 17, direct access to this class will result in a compilation error.
1import sun.misc.BASE64Encoder; // Compilation error in Java 17
2
3public class Example {
4 public static void main(String[] args) {
5 BASE64Encoder encoder = new BASE64Encoder(); // Compilation error in Java 17
6 // Rest of the code
7 }
8}
In the code above, attempting to import and use the sun.misc.BASE64Encoder class will result in a compilation error in Java 17. This is because this class is now strongly encapsulated and not intended for direct use.
Benefits of Strong Encapsulation
The introduction of strongly encapsulated JDK internals brings several benefits:
Improved Security: By restricting direct access to internal JDK classes, potential security vulnerabilities are minimized. Developers are encouraged to use public APIs and follow best practices, reducing the risk of unintended security breaches.
Enhanced Maintainability: With stricter encapsulation, the JDK internals are free to evolve and change between JDK releases. Developers can rely on the stable public APIs, making their code more maintainable and easily adaptable to newer JDK versions.
Reduced Code Coupling: Strong encapsulation discourages reliance on internal JDK classes. Developers are encouraged to use supported public APIs, which leads to loosely coupled code and better separation of concerns.
Conclusion
JEP 403: Strongly Encapsulated JDK Internals is an important feature introduced in Java 17. By enforcing stricter encapsulation, this feature improves security, maintainability, and code quality. Developers are encouraged to rely on public APIs and best practices, fostering a more robust and secure Java ecosystem.
Exploring Java 17: JEP 406 - Pattern Matching for Switch
Java 17 introduces a new feature called Pattern Matching for Switch, which simplifies conditional logic and enhances code readability. This feature allows developers to extract values from objects and perform operations directly within switch statements. In this article, we’ll explore JEP 406 and understand how pattern matching for switch can benefit Java developers.
Understanding Pattern Matching for Switch
Traditionally, switch statements in Java have been used to match a single value against multiple cases and perform different actions based on the matched case. However, prior to Java 17, switch statements required explicit casting or additional code to extract values from objects.
Pattern matching for switch simplifies this process by allowing developers to match and extract values from objects directly within the switch statement. This eliminates the need for explicit casting and makes the code more concise and readable.
Example: Using Pattern Matching for Switch
Let’s consider an example to understand how pattern matching for switch works. Imagine we have a Shape class hierarchy with different subclasses such as Circle, Rectangle, and Triangle. We want to calculate the area of each shape using pattern matching for switch.
1public double calculateArea(Shape shape) {
2 double area = switch (shape) {
3 case Circle c -> Math.PI * c.getRadius() * c.getRadius();
4 case Rectangle r -> r.getLength() * r.getWidth();
5 case Triangle t -> (t.getBase() * t.getHeight()) / 2.0;
6 default -> throw new IllegalArgumentException("Unknown shape: " + shape);
7 };
8 return area;
9}
In the above code, we define a method calculateArea that takes a Shape object as a parameter. Within the switch statement, we use the arrow (->) syntax along with the type pattern (Circle c, Rectangle r, Triangle t) to match and extract the values from the corresponding objects.
For example, when the shape is of type Circle, the value is assigned to the pattern variable c, allowing us to directly access the getRadius() method and calculate the area using the formula Math.PI * c.getRadius() * c.getRadius().
Similarly, for Rectangle, we assign the value to r and calculate the area using r.getLength() * r.getWidth(). And for Triangle, we assign the value to t and calculate the area using (t.getBase() * t.getHeight()) / 2.0.
The default case is used to handle any unknown shapes and throws an IllegalArgumentException to indicate that the shape is not recognized.
Benefits of Pattern Matching for Switch
Pattern matching for switch offers several benefits to Java developers:
1. Improved Readability
Pattern matching for switch reduces the need for explicit casting or additional code, making the switch statements more concise and readable. The code becomes more focused on the logic rather than the boilerplate code.
2. Simplified Conditional Logic
By allowing developers to extract values from objects directly within switch statements, pattern matching simplifies the conditional logic, making it easier to handle different cases without additional if-else statements or explicit casting.
3. Enhanced Productivity
With pattern matching for switch, developers can write more expressive and compact code, resulting in increased productivity. It eliminates the need to write repetitive and error-prone casting code, saving time and effort.
Conclusion
JEP 406: Pattern matching for switch is an exciting addition to Java 17, bringing improved readability and simplified conditional logic to switch statements. By allowing developers to match and extract values from objects directly within switch statements, Java code becomes more concise and expressive. As a Java developer, embracing this feature will enhance your coding experience and make your code more readable and efficient.
So, the next time you find yourself working with switch statements, remember to leverage the power of pattern matching for switch in Java 17 to simplify your code and improve your productivity.
Exploring Java 17: Removal of RMI Activation
In the world of Java, Remote Method Invocation (RMI) has long been used for distributed computing, allowing objects to invoke methods on remote objects. However, with the release of Java 17, a significant change has been introduced with JEP 407, which focuses on the removal of RMI Activation.
Understanding RMI Activation
RMI Activation is a feature that enables objects to be activated on demand when needed. It provides a way to manage the lifecycle of remote objects, automatically activating them when a method call is made and deactivating them when they are no longer in use. This feature has been part of Java for many years but has become less relevant and widely used in modern distributed applications.
Why Remove RMI Activation?
As Java evolves, certain features become less relevant or are replaced by more modern alternatives. RMI Activation, although once popular, has become less used and has been superseded by newer technologies like messaging queues, microservices, and cloud-based architectures. Removing this feature simplifies the Java ecosystem, reduces maintenance efforts, and improves performance.
Impact on Existing Code
The removal of RMI Activation has an impact on existing code that relies on this feature. If your codebase currently uses RMI Activation, you will need to migrate to alternative solutions. Fortunately, there are numerous alternatives available, such as utilizing messaging queues or implementing custom object activation mechanisms tailored to your specific requirements.
Example: Migrating from RMI Activation to Messaging Queue
To help you understand the migration process, let’s consider an example where RMI Activation is used to activate and deactivate a remote object. We’ll showcase how you can migrate this functionality to a messaging queue-based solution.
Suppose we have a remote object called PaymentService that needs to be activated when a payment request is received and deactivated after processing the request. Previously, RMI Activation was used to handle this lifecycle automatically. However, with the removal of RMI Activation, we can leverage a messaging queue to achieve the same functionality.
Here’s how the migration might look using a messaging queue:
1// Original RMI Activation Code
2public class PaymentService implements Remote, Serializable {
3 // ...
4 public void processPayment(Payment payment) {
5 // Payment processing logic
6 }
7 // ...
8}
9
10// Migrated Code using Messaging Queue
11public class PaymentService implements Serializable {
12 // ...
13 public void processPayment(Payment payment) {
14 // Publish payment request to the messaging queue
15 messagingQueue.publish(payment);
16 }
17
18 // Subscriber class to handle the payment requests from the queue
19 public class PaymentRequestSubscriber {
20 @Subscribe
21 public void handlePaymentRequest(Payment payment) {
22 // Payment processing logic
23 }
24 }
25 // ...
26}
In the migrated code, we remove the Remote interface and the RMI-specific activation logic. Instead, we publish the payment request to a messaging queue using a suitable messaging framework like Apache Kafka or RabbitMQ. We also introduce a subscriber class that listens to payment requests from the queue and handles them accordingly.
This migration allows us to achieve similar functionality to RMI Activation while utilizing modern messaging queue technologies. By decoupling the object activation from the object itself, we can build more flexible and scalable distributed systems.
Conclusion
With the removal of RMI Activation in Java 17, the Java ecosystem continues to evolve, streamlining and modernizing its features. Although this removal may require some adjustments for existing codebases that rely on RMI Activation, there are various alternative solutions available. By migrating to newer technologies like messaging queues or implementing custom object activation mechanisms, you can continue to build robust and efficient distributed systems in Java.
Exploring Java 17: JEP 409: Sealed Classes
In the world of Java programming, classes and inheritance play a vital role. With the introduction of Java 17, a new feature called Sealed Classes, specified in JEP 409, has been added to the language. This feature enhances control over class inheritance, providing more flexibility and security.
Understanding Sealed Classes
In Java, classes can be extended by other classes to create a class hierarchy. However, there are scenarios where you want to restrict the inheritance of certain classes to maintain code integrity. Sealed Classes address this by allowing you to explicitly define which classes can extend a particular class.
Example of Sealed Classes
To better understand Sealed Classes, let’s consider an example of a class hierarchy related to shapes:
1public abstract sealed class Shape permits Circle, Rectangle {
2 // Common properties and methods for shapes
3}
4
5public final class Circle extends Shape {
6 // Circle-specific properties and methods
7}
8
9public final class Rectangle extends Shape {
10 // Rectangle-specific properties and methods
11}
In the above example, the Shape class is declared as abstract sealed, which means it is a sealed class. It restricts the classes that can extend it to Circle and Rectangle using the permits keyword. This declaration explicitly specifies that only these two classes are allowed to inherit from Shape. Any attempt to create another class extending Shape will result in a compilation error.
Benefits of Sealed Classes
Sealed Classes provide several benefits:
Controlled Inheritance: Sealed Classes offer more control over class inheritance. By explicitly specifying which classes can extend a sealed class, you can prevent unauthorized or unintended extensions, ensuring that the class hierarchy adheres to your design and requirements.
Enhanced Encapsulation: Sealed Classes improve encapsulation by limiting the number of classes that can extend a sealed class. This restriction allows you to better encapsulate the behavior and implementation details of the sealed class, reducing the risk of unintended modifications from external sources.
Maintainability: With sealed classes, it becomes easier to maintain and evolve the class hierarchy over time. By explicitly defining the permitted subclasses, you can introduce new subclasses or modify existing ones without worrying about unintended consequences or breaking existing code.
Using Sealed Classes in Real-World Scenarios
Sealed Classes are particularly useful in scenarios where you want to define a fixed set of subclasses for a specific superclass. This can be seen in areas such as frameworks, APIs, or domain-specific modeling.
For instance, imagine a scenario where you are developing a game engine, and you have a sealed class called GameObject that represents the base entity in the game. You can then define subclasses like Player, Enemy, and Obstacle that are permitted to extend the GameObject class. This ensures that the game entities are well-defined and provides a clear structure for game developers.
Conclusion
Sealed Classes introduced in Java 17 through JEP 409 offer a valuable addition to the Java language, providing enhanced control and encapsulation over class inheritance. By explicitly defining which classes can extend a sealed class, you can maintain code integrity, improve security, and make your codebase more maintainable.
When designing class hierarchies, consider using sealed classes to enforce a controlled and well-defined inheritance structure, particularly in scenarios where a limited set of subclasses should be allowed. Embrace the power of sealed classes in Java 17 to build robust and maintainable applications.
Exploring Java 17: JEP : 410 Removal of Experimental AOT and JIT Compiler
In the world of Java programming, the Ahead-of-Time (AOT) and Just-in-Time (JIT) compilers play crucial roles in optimizing and executing Java code. However, with the release of Java 17, a significant change has been introduced with JEP 410, which focuses on the removal of the experimental AOT and JIT compilers.
Understanding AOT and JIT Compilation
Java employs two main types of compilation: AOT and JIT.
Ahead-of-Time (AOT) Compilation: AOT compilation converts Java bytecode into machine code before execution. This allows for faster startup times but can limit runtime optimizations.
Just-in-Time (JIT) Compilation: JIT compilation dynamically compiles Java bytecode into machine code during runtime, optimizing the code for better performance. JIT compilation trades off initial startup time for improved runtime execution speed.
Why Remove Experimental AOT and JIT Compiler?
The experimental AOT and JIT compilers were introduced in previous versions of Java to explore alternative compilation strategies and improve performance. However, they remained experimental and were not fully supported or widely used. As Java evolves, focusing on the primary HotSpot JIT compiler provides better stability, performance, and maintenance benefits. Hence, the decision has been made to remove the experimental AOT and JIT compilers in Java 17.
Impact on Existing Code
The removal of the experimental AOT and JIT compilers does not have a direct impact on existing Java codebases. The primary HotSpot JIT compiler, which is widely used and supported, remains unaffected. Your existing Java applications will continue to work as expected, utilizing the reliable HotSpot JIT compiler for runtime optimizations.
Example: Traditional JIT Compilation
To better understand the impact of removing the experimental AOT and JIT compilers, let’s consider an example that showcases the traditional JIT compilation process.
1public class MathUtils {
2 public static int square(int number) {
3 return number * number;
4 }
5
6 public static void main(String[] args) {
7 int result = square(5);
8 System.out.println("Square of 5 is: " + result);
9 }
10}
In the above code, we have a simple MathUtils class that calculates the square of a given number using the square method. When the main method is executed, the JIT compiler analyzes the code and optimizes it for better performance during runtime. This includes optimizing loops, inlining method calls, and applying other runtime-specific optimizations.
With the removal of the experimental AOT and JIT compilers, the traditional JIT compilation process remains unaffected. The reliable HotSpot JIT compiler continues to optimize the code, ensuring efficient execution.
Conclusion
With the removal of the experimental AOT and JIT compilers in Java 17 through JEP 410, the focus remains on the reliable and widely used HotSpot JIT compiler. This decision ensures stability, performance, and maintenance benefits for the Java ecosystem.
As a developer, you don’t need to worry about the removal of the experimental compilers, as your existing Java codebase will continue to utilize the powerful HotSpot JIT compiler for runtime optimizations. Embrace Java 17’s reliable compilation process and enjoy the benefits of a stable and performant Java platform.
Exploring Java 17: Deprecating the Security Manager
With the release of Java 17, a significant change has been introduced with JEP 411. This JEP focuses on deprecating the Security Manager, a feature that has been part of Java’s security model for a long time. Let’s understand what the Security Manager is, why it is being deprecated, and how it impacts Java developers.
Understanding the Security Manager
The Security Manager is a component of Java’s security architecture that allows applications to enforce security policies. It provides a means to define and enforce fine-grained access control to system resources, such as file systems, network sockets, and threads. The Security Manager has been used in Java applications to restrict certain operations and protect against malicious code.
Deprecating the Security Manager
The decision to deprecate the Security Manager in Java 17 is driven by a few factors. Over the years, the Java platform has evolved, and new security mechanisms have been introduced. Additionally, the Security Manager has posed certain challenges and limitations in terms of performance, maintainability, and compatibility with modern security frameworks.
Impact on Existing Code
The deprecation of the Security Manager means that its usage is discouraged, and it is expected to be removed in future versions of Java. For developers who have relied on the Security Manager in their applications, it is recommended to migrate to alternative security mechanisms and frameworks that align with modern security practices.
Example: Migrating from Security Manager to Security APIs
To help you understand the migration process, let’s consider an example where the Security Manager is used to restrict file access within an application. We’ll showcase how you can migrate this functionality to the newer security APIs available in Java.
1// Original Code with Security Manager
2public class FileProcessor {
3 private static final SecurityManager securityManager = new SecurityManager();
4
5 public void processFile(String filePath) {
6 // Check if the Security Manager allows file access
7 securityManager.checkRead(filePath);
8
9 // File processing logic
10 }
11}
In the above code, the SecurityManager class is used to check if the application has permission to read the specified file. To migrate away from the Security Manager, we can leverage the newer security APIs provided by Java, such as the Files class and the SecurityManager methods available through the Security class.
1// Migrated Code using Security APIs
2public class FileProcessor {
3 public void processFile(String filePath) {
4 // Check if the security manager allows file access
5 SecurityManager security = System.getSecurityManager();
6 if (security != null) {
7 security.checkRead(filePath);
8 }
9
10 // File processing logic
11 }
12}
In the migrated code, we utilize the System.getSecurityManager() method to obtain the security manager, if present, and then perform the necessary security checks using the available checkRead() method. This approach allows for a smoother transition from the deprecated Security Manager to the newer security APIs.
Conclusion
With JEP 411, the Security Manager has been deprecated in Java 17, signaling its eventual removal from future versions. While the deprecation of the Security Manager may require adjustments in existing codebases, it aligns with the evolution of Java’s security architecture and encourages the adoption of modern security practices and frameworks.
Exploring Java 17: Foreign Function & Memory API
In the Java programming language, interoperability with native code and accessing low-level system resources has always been a challenge. However, with the introduction of Java 17, a new feature called the Foreign Function & Memory API, specified in JEP 412, has been added to the language. This API enables developers to interact with native code and manage memory more efficiently.
Understanding the Foreign Function & Memory API
The Foreign Function & Memory API provides a way to interact with native code written in languages like C and C++. It allows Java programs to call functions and access data structures defined in native libraries, providing a bridge between the Java Virtual Machine (JVM) and native code.
Example of Using the Foreign Function & Memory API
To better understand the Foreign Function & Memory API, let’s consider an example where we want to call a C library function from a Java program.
Suppose we have a C library called mathlib that provides a function int square(int num). The goal is to call this function from our Java program using the Foreign Function & Memory API.
Here’s how the Java code would look like:
1import jdk.incubator.foreign.*;
2
3public class MathLibExample {
4 public static void main(String[] args) {
5 try (var scope = ResourceScope.newConfinedScope()) {
6 LibraryLookup mathLib = LibraryLookup.ofLibrary("mathlib");
7 FunctionDescriptor squareDescriptor = FunctionDescriptor.of(CLinker.C_INT, CLinker.C_INT);
8 FunctionHandle squareFunction = mathLib.lookup("square").get().address().bindTo(squareDescriptor);
9
10 int num = 5;
11 MemorySegment result = MemorySegment.allocateNative(CLinker.C_INT);
12 squareFunction.invoke(result.asSegment(), num);
13
14 int squaredNum = result.getI32(0);
15 System.out.println("Square of " + num + " is: " + squaredNum);
16 }
17 }
18}
In the above code, we use the LibraryLookup class to load the mathlib library. We then create a FunctionDescriptor to describe the function signature and use it to look up the square function from the library. We allocate native memory using MemorySegment to store the result of the function call.
We then invoke the square function by passing the memory segment and the input value. Finally, we retrieve the squared number from the memory segment and print the result.
Benefits of the Foreign Function & Memory API
The Foreign Function & Memory API brings several benefits:
Native Code Interoperability: The API enables Java programs to seamlessly interact with native code, opening up possibilities for leveraging existing libraries and integrating with system-level functionality.
Efficient Memory Management: The API provides a more efficient and controlled way of managing native memory, reducing memory leaks and improving overall performance.
Improved Performance: By calling native functions directly, developers can achieve better performance for certain tasks that are more efficiently handled in native code.
Platform Portability: The API allows developers to write platform-independent code that can be used across different operating systems, as long as the corresponding native libraries are available.
Conclusion
With the introduction of the Foreign Function & Memory API in Java 17, the language gains the ability to seamlessly interact with native code and manage memory more efficiently. This opens up new opportunities for leveraging existing libraries, integrating with system-level functionality, and improving performance for certain tasks.
While using the Foreign Function & Memory API, it’s important to follow best practices and ensure proper memory management to avoid memory leaks.
Exploring Java 17: Vector API (Second Incubator)
In the world of Java programming, performing vectorized computations on arrays is essential for efficient and parallel processing. With the introduction of Java 17, a new feature called the Vector API (Second Incubator), specified in JEP 414, has been added to the language. This feature aims to provide a convenient and efficient way to perform vector computations on arrays.
Understanding the Vector API
The Vector API provides a set of classes and methods that enable developers to perform vector operations, such as adding, subtracting, multiplying, or dividing elements of arrays in a highly optimized manner. These operations leverage the hardware’s vector instructions, enabling faster and parallel execution.
Example of Vector API Usage
To better understand the Vector API, let’s consider an example where we want to multiply corresponding elements of two arrays and store the results in a third array.
1import java.util.Arrays;
2import jdk.incubator.vector.*;
3
4public class VectorExample {
5 public static void main(String[] args) {
6 float[] array1 = {1.0f, 2.0f, 3.0f, 4.0f};
7 float[] array2 = {2.0f, 2.0f, 2.0f, 2.0f};
8 float[] result = new float[4];
9
10 try (VectorSpecies<Float> species = FloatVector.SPECIES_PREFERRED) {
11 int i = 0;
12 for (; i < array1.length - species.length(); i += species.length()) {
13 FloatVector vec1 = FloatVector.fromArray(species, array1, i);
14 FloatVector vec2 = FloatVector.fromArray(species, array2, i);
15 FloatVector vecResult = vec1.mul(vec2);
16 vecResult.intoArray(result, i);
17 }
18
19 for (; i < array1.length; i++) {
20 result[i] = array1[i] * array2[i];
21 }
22 }
23
24 System.out.println(Arrays.toString(result));
25 }
26}
In the above example, we create two arrays, array1 and array2, containing float values. We then create a third array, result, to store the multiplication results. Inside the try block, we use the VectorSpecies class to obtain the preferred vector species for the float type.
We then iterate over the arrays in chunks of the vector length, which is determined by the species.length() method. For each chunk, we create FloatVector instances from the corresponding portions of array1 and array2. We multiply the vectors using the mul method and store the results in vecResult. Finally, we use the intoArray method to store the vector results back into the result array.
For any remaining elements beyond the vector length, we perform a scalar multiplication. Finally, we print the result array, which contains the multiplication results.
Benefits of the Vector API
The Vector API offers several benefits:
Improved Performance: By utilizing hardware vector instructions, the Vector API enables faster and parallel computation, resulting in improved performance for vectorized operations.
Simplified Vector Computation: The Vector API provides a high-level abstraction for vector operations, making it easier to write and understand vectorized code.
Portability: The Vector API is designed to be portable across different hardware architectures, allowing developers to write vectorized code that can run efficiently on various platforms.
Conclusion
The Vector API (Second Incubator) introduced in Java 17 through JEP 414 provides a powerful mechanism for performing vector computations on arrays. By leveraging hardware vector instructions, developers can achieve improved performance and parallelism for vectorized operations.
When dealing with computationally intensive tasks involving arrays, consider utilizing the Vector API to harness the power of vectorization and optimize your code for faster execution. Embrace the Vector API in Java 17 to unlock the potential of efficient and parallel computations in your applications.
Exploring Java 17: Context-Specific Deserialization Filters
In the Java programming language, object serialization and deserialization allow objects to be converted into a byte stream for storage or transmission. With the introduction of Java 17, a new feature called Context-Specific Deserialization Filters, specified in JEP 415, has been added to provide enhanced security and control over deserialization.
Understanding Context-Specific Deserialization Filters
Deserialization is the process of converting a byte stream back into an object. It is an essential feature for transferring objects across networks or storing them in persistent storage. However, deserialization can also pose security risks, as malicious code can be injected during the deserialization process.
To mitigate these risks, Java 17 introduces Context-Specific Deserialization Filters. These filters allow developers to specify custom logic that determines whether an object should be deserialized or not, based on the context in which the deserialization occurs.
Example of Context-Specific Deserialization Filters
Let’s consider an example where we have a class called Employee that represents employee data. We want to ensure that the deserialization of Employee objects only occurs within a trusted context.
1public class Employee implements Serializable {
2 private String name;
3 private int age;
4
5 // Constructors, getters, and setters
6}
To apply a context-specific deserialization filter, we can implement the ObjectInputFilter interface and define our custom filter logic. Here’s an example:
1public class EmployeeFilter implements ObjectInputFilter {
2 @Override
3 public Status checkInput(FilterInfo filterInfo) {
4 Class<?> clazz = filterInfo.serialClass();
5 String className = clazz.getName();
6
7 // Allow deserialization of Employee objects
8 if (className.equals("com.example.Employee")) {
9 return Status.ALLOWED;
10 }
11
12 // Deny deserialization for all other classes
13 return Status.REJECTED;
14 }
15}
In the above code, we implement the ObjectInputFilter interface and override the checkInput method. Inside the method, we inspect the class being deserialized (filterInfo.serialClass()) and make a decision based on its name. In this example, we allow deserialization only for the Employee class and reject deserialization for all other classes.
Benefits of Context-Specific Deserialization Filters
Context-Specific Deserialization Filters provide several benefits:
Enhanced Security: By allowing developers to define custom filters, deserialization can be restricted to trusted classes or contexts, preventing the execution of malicious code during deserialization.
Fine-Grained Control: With context-specific filters, you have granular control over which classes are allowed or denied during deserialization. This enables you to define specific rules based on your application’s security requirements.
Flexibility: Context-specific filters can be customized based on different contexts, allowing different deserialization behaviors in various parts of your application. This flexibility ensures that deserialization is controlled appropriately in each scenario.
Using Context-Specific Deserialization Filters in Real-World Scenarios
Context-Specific Deserialization Filters are particularly useful in scenarios where deserialization occurs in potentially untrusted environments, such as when receiving serialized objects over a network or reading data from untrusted sources.
For example, in a client-server architecture, you can apply context-specific filters on the server-side to ensure that only known and trusted classes are deserialized. This helps protect the server from deserialization attacks and ensures the integrity of the system.
Conclusion
Java 17 introduces Context-Specific Deserialization Filters through JEP 415, enhancing security and control over the deserialization process. By implementing custom filters, you can restrict deserialization to trusted classes or contexts, mitigating the risks associated with deserialization attacks.
When working with deserialization, consider utilizing context-specific filters to ensure the safety and integrity of your application. Embrace this new feature in Java 17 to enhance the security of your serialized objects and protect your systems from potential vulnerabilities.