Java 17 Features

• Overview of Java 17 release
• Importance of Java in modern software development
• Key features and improvements in Java 17

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Pattern Matching for Switch Statements (JEP 406)

• Explanation of pattern matching in switch statements
• Example: Simplifying code with pattern matching

// Example of pattern matching in switch statements
public String getDayOfWeekName(int day) {
    return switch (day) {
        case 1 -> "Monday";
        case 2 -> "Tuesday";
        case 3 -> "Wednesday";
        case 4 -> "Thursday";
        case 5 -> "Friday";
        case 6 -> "Saturday";
        case 7 -> "Sunday";
        default -> throw new IllegalArgumentException("Invalid day of the week: " + day);
    };
}

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Sealed Classes (JEP 409)

• Introduction to sealed classes and interfaces
• Example: Defining a sealed class hierarchy

// Example of sealed classes
public sealed interface Shape permits Circle, Rectangle, Triangle {
    // Common methods for all shapes
}

public final class Circle implements Shape {
    // Circle-specific implementation
}

public final class Rectangle implements Shape {
    // Rectangle-specific implementation
}

public final class Triangle implements Shape {
    // Triangle-specific implementation
}

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Vector API (Incubator, JEP 417)

• Overview of Vector API for SIMD (Single Instruction, Multiple Data)
• Example: Performing vectorized calculations

// Example of Vector API
import java.util.Vector;

public class VectorExample {
    public static void main(String[] args) {
        Vector<Float> vec1 = Vector.of(1.0f, 2.0f, 3.0f);
        Vector<Float> vec2 = Vector.of(4.0f, 5.0f, 6.0f);
        Vector<Float> result = vec1.add(vec2);
        System.out.println("Vector addition result: " + result);
    }
}

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Slide 5: Foreign Function & Memory API (Incubator, JEP 419)

• Introduction to Foreign Function & Memory API for interacting with native code and memory
• Example: Using Foreign Function & Memory API

// Example of Foreign Function & Memory API
import jdk.incubator.foreign.*;

public class MemoryExample {
    public static void main(String[] args) {
        try (MemorySegment segment = MemorySegment.allocateNative(1024)) {
            segment.asByteBuffer().putString("Hello, Java 17!");
            System.out.println("Message stored in native memory: " + segment.toString());
        }
    }
}

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Slide 6: Persistent Java (Incubator, JEP 390)

• Overview of Persistent Java for native access to persistent memory
• Example: Using Persistent Java API

// Example of Persistent Java API
import jdk.incubator.pm.*;

public class PersistentJavaExample {
    public static void main(String[] args) throws Exception {
        try (HeapTransaction txn = HeapTransaction.create("transaction")) {
            PersistentMemorySegment segment = PersistentMemorySegment.allocateNative(1024);
            segment.setByteAtOffset(0, (byte) 65); // Store 'A' in persistent memory
            txn.commit();
        }
    }
}

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Other Enhancements and Updates

• Compact Number Formatting (JEP 406)
• Strongly Encapsulate JDK Internals by Default (JEP 396)
• Remove the Experimental AOT and JIT Compiler (JEP 410)

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Best Practices and Tips

• Best practices for adopting Java 17 features:
  • Gradual migration to new language features
  • Testing and compatibility considerations
  • Leveraging IDE support for Java 17 features

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Use Cases and Industries Adopting Java 17

• Examples of industries leveraging Java 17:
  • Finance for transaction processing and risk management
  • Healthcare for electronic health records and patient management systems
  • E-commerce for scalable backend systems and real-time analytics

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Conclusion

• Recap of Java 17 concepts and examples covered
• Importance of upgrading to Java 17 for modern software development
• Resources for further learning and exploration

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Additional Resources

• Java 17 Documentation: docs.oracle.com/javase/17
• JDK Enhancement Proposals (JEPs): openjdk.java.net/jeps
• Online tutorials, blogs, and community forums for Java 17 learning