How do I make a rest api call in a runnable?

Question

I have a several readers where I am reading continuously for rfid tags. I want to check these tags with what is in a database. I have a spring app that uses runnables to connect and get info from the readers. I'm adding the tags to a queue. I have a rest api that is running separately that will be used by this application. I want to use this api while the reader app is running to check the database multiple times as well as add info to the database. How do I do this?

I've tried multiple things such as using completablefuture, trying to use webflux, using resttemplate to make api calls, webclient to make api calls but nothing seems to work. I have an executor service that calls the readers from the main. Each reader is created with a runnable. The runnable creates the Reader and calls the function. In that function, 2 runnable tasks start. In one of these tasks I want to call the rest api. I will try and include all the code that is necessary.

This is the class that is called from main:

@Component
@Scope("prototype")
public class CSLReader{
public CSLReader(String ipAddress){
    this.ipAddress=ipAddress;
}

public CSLReader(String ipAddress, String deviceName, int power, int 
notifyPort, int dwellTime ) throws InterruptedException{
    this.ipAddress=ipAddress;
    this.deviceName=deviceName;
    this.power=power;
    this.notifyPort=notifyPort;
    this.TagBuffer = new LinkedList<TagInfo>();
    //this.taglist=new ArrayBlockingQueue<TagInfo>();
    this.dwellTime=dwellTime;
    //Start();
}

public void StartAsync() throws InterruptedException, IOException{

     Runnable task = new Runnable() {

            @Override
            public void run() {
                try {
                    StartInventory();
                } catch (Exception ex) {

                    System.out.print("start 
  inventory thread could not start: "+ex.getLocalizedMessage());
                    ex.printStackTrace();
                }
            }


        };
        Runnable task2 = new Runnable() {

            @Override
            public void run() {
                try {
                    StartTCPClient();

                } catch (Exception ex) {
                    System.out.print("start 
tcpclient thread could not start: "+ex.getMessage());
                }
            }
        };

        tcpClientThread = new Thread(task2, "TCPClientThread");
       tcpClientThread.setDaemon(true);
        tcpClientThread.start();

      inventoryThread = new Thread(task, "InventoryThread");
        inventoryThread.setDaemon(true);
        inventoryThread.start();
    }

I have this in the a service file:

@Async
public CompletableFuture<BmwvehicleTest> findVehicle(String rfidtag) throws InterruptedException{
    log.info("trying to find a vehicle test by rfidtag");
    String getUrl=String.format("http://localhost/api/tag/", rfidtag);
    BmwvehicleTest results= restTemplate.getForObject(getUrl,BmwvehicleTest.class);
    Thread.sleep(2000L);
    return CompletableFuture.completedFuture(results);
}

Then I try and call it in my main prototype component:

public void StartInventory() throws InterruptedException,  
   ExecutionException{      
ArrayBlockingQueue<TagInfo> taglist= new ArrayBlockingQueue<TagInfo>(10000);


    synchronized (TagBuffer) {
        if (TagBuffer.size() >= 10000){
            TagBuffer.remove();
        }
//test tag
        TagInfo tag2= new TagInfo(51.2f, 2, "192.168.68.68", "Test Reader", new Date(), 0, "E200287878787878787", "3400");
        if (tag2 != null){

            TagBuffer.add(tag2);
            System.out.println("tag added to tag buffer");
            log.info("the tag is: "+tag2.epc);  

CompletableFuture<BmwvehicleTest> num1=asyncServices.findVehicle(tag2.epc);
}
}
}

I would like the app to continue receiving info from the readers and when a tag is received to add the tag to the queue, then checked to see if in the database, if so I want the location added to the database. While this is happening, I still want the app to continue receiving info from the readers.