Java AtomicLong class

import java.util.concurrent.atomic.AtomicLong;
class Account {/* ww  w  . ja  va  2s . c  o m*/

  private AtomicLong balance;
  
  public Account(){
    balance=new AtomicLong();
  }
  public long getBalance() {
    return balance.get();
  }
  public void setBalance(long balance) {
    this.balance.set(balance);
  }
  public void addAmount(long amount) {
    this.balance.getAndAdd(amount);
  }
  
  public void subtractAmount(long amount) {
    this.balance.getAndAdd(-amount);
  }
  
}
class Bank implements Runnable {

  private Account account;
  
  public Bank(Account account) {
    this.account=account;
  }
  
  @Override
  public void run() {
    for (int i=0; i<10; i++){
      account.subtractAmount(1000);
    }
  }

}
 class Company implements Runnable {
  private Account account;
  public Company(Account account) {
    this.account=account;
  }
  @Override
  public void run() {
    for (int i=0; i<10; i++){
      account.addAmount(1000);
    }
  }
}
public class Main {
  public static void main(String[] args) {
    Account account=new Account();
    account.setBalance(1000);
    
    Company company=new Company(account);
    Thread companyThread=new Thread(company);
    Bank bank=new Bank(account);
    Thread bankThread=new Thread(bank);
    
    System.out.printf("Account : Initial Balance: %d\n",account.getBalance());
    
    // Starts the Threads
    companyThread.start();
    bankThread.start();

    try {
      companyThread.join();
      bankThread.join();
      System.out.printf("Account : Final Balance: %d\n",account.getBalance());
    } catch (InterruptedException e) {
      e.printStackTrace();
    }
  }
}