Java 25

1.txt

# ทำการติดตั้งและ config Java 25 :: https://jdk.java.net/25/

$javac -version
javac 25

$java -version                     
openjdk version "25" 2025-09-16
OpenJDK Runtime Environment (build 25+35-3488)
OpenJDK 64-Bit Server VM (build 25+35-3488, mixed mode, sharing)

Demo01.java

class Demo01 {
    void main(String[] args) {
        int a = 10;
        if (a instanceof int i) {
            System.out.println("a is an int: "+ i);
        }
    }
}

# Run
$javac --enable-preview --release 25 Demo01.java
$java --enable-preview Demo01
a is an int: 10

DemoConcurrency.java

import java.util.concurrent.StructuredTaskScope;

public class DemoConcurrency {

    static Integer process1() {
        System.out.println("Processing in process 1");
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            System.out.println("Thread 1 interrupted");
        }
        return 2000; // Simulating some processing result
    }

    static Integer process2() {
        System.out.println("Processing in process 2");
        try {
            Thread.sleep(1000);
        } catch (InterruptedException e) {
            System.out.println("Thread 2 interrupted");
        }
        return 1000; // Simulating some processing result
    }

    // Main method to run the demo
    void main(String[] args) {
        try (var scope = StructuredTaskScope.<Integer>open()) {
            var firstProcess = scope.fork(() -> process1());
            var secondProcess = scope.fork(() -> process2());

            scope.join();

            System.out.println("Process 1 result: " + firstProcess.get());
            System.out.println("Process 2 result: " + secondProcess.get());
        } catch (Exception e) {
            System.out.println("An error occurred: " + e.getMessage());
        }
    }   
}

# Run
$javac --enable-preview --release 25 DemoConcurrency.java
$java --enable-preview DemoConcurrency                   
Processing in process 1
Processing in process 2
Process 1 result: 2000
Process 2 result: 1000

DemoConstructor.java

class Base {
    final int x;
    Base(int x) {
        this.x = x;
    }
}

class Derived extends Base {
    Derived(int x) {
        if(x <10) {
            throw new IllegalArgumentException("x must be at least 10");
        }
        super(x);
    }
}

public class DemoConstructor {
    void main(String[] args) {
        Derived d1 = new Derived(15);
        System.out.println("Derived x: " + d1.x);
        Derived d2 = new Derived(5);
        System.out.println("Derived x: " + d2.x);
    }
}

# Run
$javac DemoConstructor.java
$java DemoConstructor      
Derived x: 15
Exception in thread "main" java.lang.IllegalArgumentException: x must be at least 10
	at Derived.<init>(DemoConstructor.java:11)
	at DemoConstructor.main(DemoConstructor.java:21)

DemoModule.java

import module java.base;

public class DemoModule {

    void main(String[] args) {
        Date currentDate = new Date();
        System.out.println("Current date: " + currentDate);
    }
    
}

# Run
$javac --enable-preview --release 25 DemoModule.java
$java --enable-preview DemoModule                   
Current date: Thu Aug 14 22:45:28 GMT+07:00 2025

Hello.java

void main(String[] args) {  
    IO.println("Hello, Java 25!!");
}

# Run
$javac Hello.java
$java Hello 
Hello, Java 25!!