threadsafe queue

package com.aaaaa.bbbbb.threads;

import com.aaaaa.bbbbb.Main;
import com.aaaaa.bbbbb.tasks.Task;

import java.util.*;

public class TaskHandler extends Thread {

    private List<Task> taskList = Collections.synchronizedList(new ArrayList<>());
    private List<Task> toAdd = Collections.synchronizedList(new ArrayList<>());
    Timer timer = new Timer();

    public TaskHandler(Main s) {
        super();
    }

    public void run() {
        while (true) {
            try {
                taskList.addAll(toAdd);
                toAdd.clear();
                Iterator<Task> itr = taskList.iterator();
                while(itr.hasNext()) {
                    Task t = itr.next();
                    if (t == null) {
                        itr.remove();
                    } else if (t.validate()) {
                        Task t2 = t.deepCopy();
                        t2.execute();
                        itr.remove();
                    }
                    //Thread.sleep(50);
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
        }
    }

    public void addTask(Task task) {
        toAdd.add(task);
    }

    public void addAllTasks(List<Task> list) {
        toAdd.addAll(list);
    }

    public String toString() {
        StringBuilder s = new StringBuilder();
        for(Task t : taskList) {
            s.append(t.toString()).append("\n");
        }
        return s.toString();
    }
}