Account.javapackagecom.buaa.account;publicabstractclassAccount{privateintid;privateStringuserName;privatedoublebalance;publicstaticintCurrentID=100;//开户时调用的构造方法publicAccount(StringuserName,doublebalance){this.userName=userName;this.balance=balance;id=CurrentID++;}//读取文件加载数据时用的构造方法publicAccount(intid,StringuserName,doublebalance){this.id=id;this.userName=userName;this.balance=balance;}publicstaticintgetCurrentID(){returnCurrentID;}publicstaticvoidsetCurrentID(intcurrentID){CurrentID+=currentID;}publicintgetId(){returnid;}publicvoidsetId(intid){this.id=id;}publicStringgetUserName(){returnuserName;}publicvoidsetUserName(StringuserName){this.userName=userName;}publicdoublegetBalance(){returnbalance;}publicvoidsetBalance(doublebalance){this.balance=balance;}//存款publicvoiddeposit(doublemoney){balance+=money;}//取款publicvoidwithdraw(doublemoney)throwsBalanceNotEnoughException{if(balance<money){thrownewBalanceNotEnoughException("余额不足！");}else{balance-=money;}}@OverridepublicStringtoString(){//TODOAuto-generatedmethodstubreturnid+"\t"+userName+"\t"+balance;}publicabstractdoubleinterest();}BalanceNotEnoughException.javapackagecom.buaa.account;publicclassBalanceNotEnoughExceptionextendsException{publicBalanceNotEnoughException(Stringmessage){super(message);}}Bank.javapackagecom.buaa.account;importjava.util.Collection;importjava.util.LinkedHashMap;importjava.util.Map;publicclassBank{//所有的用户信息都存放在此map中privateMap<Integer,Account>map=newLinkedHashMap<Integer,Account>();//开户，向map中加入一个Account对象publicvoidinsertAccount(Accountaccount){map.put(account.getId(),account);}//以数组的形式返回map中的所有数据publicAccount[]getAllAccount(){Collection<Account>c=map.values();Account[]a=c.toArray(newAccount[0]);returna;}publicAccountgetAccount(intid){returnmap.get(id);}}Client.java