SynchronizedCollection.java

package concurrentCollection;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;

public class SynchronizedCollection {

    public static void main(String[] args) {
        List<Integer> list= Collections.synchronizedList(new ArrayList<>());

        final Object lock=new Object();

        Thread one=new Thread(()->{
            for (int i = 0; i < 1000; i++) {

                    list.add(i);



            }
        });
        Thread two=new Thread(()->{
            for (int i = 0; i < 1000; i++) {

                    list.add(i);


            }
        });
        one.start();
        two.start();

        try {
            one.join();
            two.join();
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        }
        System.out.println(list.size());
    }

}