Java synchronization example

Main.java

class IncrementingRunnable implements Runnable {

    private final MutableInteger mutableInteger;

    public IncrementingRunnable(MutableInteger mutableInteger) {
        this.mutableInteger = mutableInteger;
    }

    @Override
    public void run() {
        for (int i = 0; i < 10_000; i++) {
            mutableInteger.increment();
        }
    }

}

public class Main {

    public static void main (String[] args) {
        List<Thread> threads = new ArrayList<>();

        // Variable to increment from multiple threads
        MutableInteger integer = new MutableInteger();
        // Run 10 threads to increment the same variable
        for (int i = 0; i < 10; i++) {
        Thread thread = new Thread(new IncrementingRunnable(integer));
            thread.start();
            threads.add(thread);
        }

        // Wait until all threads are finished
        for (Thread thread : threads) {
            thread.join();
        }

        System.out.println("Result value: " + integer.getValue());
    }

}