How Can I Retrieve the Changed Value from a Thread?

In this scenario, a thread, specifically a HandlerThread, executes within the test() method, and a value is modified within that thread. The challenge lies in returning this modified value back to the test() method for further processing or use.

One approach is to create a thread that implements the Runnable interface, as seen in the code snippet provided. Within the run() method of this thread, you can set the value as needed. Additionally, you can create a getValue() method to retrieve this value externally.

To retrieve the value, you can launch the thread, wait for it to complete (through join()), and then access the value using the getValue() method.

public class CustomThread implements Runnable {
    private volatile int value;

    @Override
    public void run() {
        value = 2;
    }

    public int getValue() {
        return value;
    }
}

In the main method:

CustomThread thread = new CustomThread();
Thread t = new Thread(thread);
t.start();
t.join();
int retrievedValue = thread.getValue();

Remember that using a volatile variable like value ensures visibility and consistency across threads.