简单顺序死锁和动态顺序死锁

//简单顺序死锁
public class LeftRightDeadlock{
    
    
  private final Object left = new Object();
  private final Object right = newe Object();

  public void leftRight(){
    
    
    synchronized(left){
    
    
      synchronized(right){
    
    
        doSomething();
      }
    }
  }


  public void rightLeft(){
    
    
    synchronized(right){
    
    
      synchronized(left){
    
    
        doSomethingElse();
      }
    }
  }
}

//动态的顺序死锁
public void transferMoney(Account fromAccount,Account toAccount,DollarAmount amount)
throws InsufficientFundsException{
    
    
  synchronized(fromAccount){
    
    
    synchronized(toAccount){
    
    
      if(fromAccount.getBalance().compareTo(amount) < 0){
    
    
      throw new InsufficientFundsException();
      }else{
    
    
        fromAccount.debit(amount);
        toAccount.credit(amount);
      }
    }
  }
}

所有线程似乎是按照相同的顺序来获得锁，但是实际上，获得锁的顺序取决于外部的输入，如果两个线程同时调用transferMoney(),其中一个线程从X向Y转账，另外一个线程
从Y向X转账，就会发生死锁