package lockmgr;/** *   Thrown to indicate that the transaction is deadlocked and should be aborted. */public class DeadlockException extends Exception{    private int xid = 0;        public DeadlockException (int xid, String msg)    {        super("The transaction " + xid + " is deadlocked:" + msg);        this.xid = xid;    }        int GetXId()    {        return xid;    }}