Deadlock example

gistfile1.java

public class Operations {
    public static void main(String[] args) {
        final Account a = new Account(1000);
        final Account b = new Account(2000);
        new Thread(new Runnable() {
            @Override
            public void run() {
                transfer(a, b, 500);
            }
        }).start();
        transfer(b, a, 300);
    }

    private static void transfer(final Account sourceAccount, final Account destAccount, final int amount) {
        System.out.println("Trying to lock source account...");
        synchronized(sourceAccount) {
            System.out.println("Source account locked.");
            try {
                Thread.sleep(1000);
            } catch(InterruptedException e) {
                e.printStackTrace();
            }
            System.out.println("Trying to lock destination account...");
            synchronized(destAccount) {
                System.out.println("Destination account locked.");
                if(sourceAccount.getBalance() < amount) throw new InsufficientFundsException();
                sourceAccount.withdraw(amount);
                destAccount.deposit(amount);
                System.out.println("Transfer complete!");
            }
        }
    }
}