Argthtjtr

I just started with Java recently. I have one variable in one class and I want to use in another class. I know that this is very basic, but if someone can help....

This is the class and the variable is value

public class MainApp {

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public static  class AnalogSampleListener implements IIOSampleReceiveListener {

    @Override

    public void ioSampleReceived(RemoteXBeeDevice remoteDevice, IOSample ioSample) {

        for (IOLine line : LINES) {

            if (ioSample.hasAnalogValue(line)) {

                int ***value*** = ioSample.getAnalogValue(line);



                System.out.println(new Timestamp(System.currentTimeMillis()) + " " + "Analog data from '" + remoteDevice.get64BitAddress() + 

                        "': " + value);



     }

  }

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}

I want to send the variable value to this class:

public class RandomWave implements Runnable{



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public void run()

{

    long currentTime = 0;

    long nextTime = 0;



    // Variable to keep track of the timing

    long timer = System.nanoTime();



    while (!stopThread)

    {

        // Compute the next data value

        currentTime = (System.nanoTime() - timer) / 1000000;



        double p = currentTime / 1000.0 * 4;

        double series0 = ***HERE I NEED THE VARIABLE VALUE***;

        double series1 = 210 + 60 * Math.sin(p / 21.7) * Math.sin(p / 7.8);



        // Call the handler

        handler.onData(currentTime / 1000.0, series0, series1);



        // Sleep until next walk

        if ((nextTime += interval) <= currentTime)

            nextTime = currentTime + interval;



        try { Thread.sleep((int)(nextTime - currentTime)); }

        catch (InterruptedException e) {};

    }

}

Thank you

You need to write a getter Method for this var. As an example i will do it with a String named "myString".

public String getMyString(){

  return myString;

}

Now you can create an Instance of the other class an call this method to get the value:

MyClass c = new MyClass();

String valueFromTheOtherClass = c.getMyString();

I hope i understood you're question right...

Value is a local variable and does not exist after "ioSampleReceived" finished.

But I like to do a very general explanation. If you need to read a value from another class, you can make it "public static". Static means that this variable does not exist for every object instance. There is only one. Living in the class, not in the object. It's quite simple for some other class to access this value. Just call "ClassA.value". But be aware of multi-threading issues which arise if your code is being executed in parallel.

It get's a bit more complicated if you have non-static values. There are many instances of ClassA and ClassB needs to be told which object instance of ClassA it has to use. Maybe have the instance of ClassA included in the constructor of ClassB. This also falls under the topic "Dependency Injection". Frameworks can help you, but after all, you need to tell ClassB about the ClassA object, before ClassB can read any values of ClassA.