Thread, wait, synchronized.

package quintaAula;

import java.util.ArrayList;

public class Fila extends Thread {

    ArrayList<String> nomes = new ArrayList<>();

    public synchronized Object remove(int i) {
        while (nomes.isEmpty()) {
            try {
                System.out.println("Tentando remover porém vazio esperando");
                this.wait(); // this.wait()
            } catch (InterruptedException ex) {
                ex.printStackTrace();
            }
        }
        return nomes.remove(i);
    }

    
    public synchronized void add(String nome) {
        System.out.println("Adicionando o elemento na lista " + nome);
        nomes.add(nome);
        notify(); // this.notifyAll()
    }
    
    @Override
    public void run() {
        
        this.add("Maria");
        this.add("Joao");
        this.impr();
    }
    
    public void impr() {
        for (String element : nomes) {
            System.out.println("Element : " + element);
        }                             
    }
    
    
    public static void main(String[] args) {
        Fila td = new Fila();
        td.start();
        td.remove(0);
       
    }
    
}