建立exception包，建立Bank類，類中有變量double balance表示存款,Bank類的構造方法能增加存款，Bank類中有取款的發方法withDrawal(double dAmount),當取款的數額大于存款時,拋出InsufficientFundsException,取款數額為負數，拋出NagativeFundsException,如new Bank(100),表示存入銀行100元，當用方法withdrawal(150)，withdrawal(-15)時會拋出自定義異常。
package exception;public class Bank {double balance;public Bank(double balance){}public void withDrawal(double dAmount) throws Exception{if(dAmount>balance){throw new InsufficientFundsException();}if(dAmount<0){throw new NagativeFundsException();}balance =balance-dAmount;}}
package exception;public class InsufficientFundsException extends Exception {@Overridepublic String getMessage() {// TODO 自動生成的方法存根return "余額不足！";}}
package exception;public class NagativeFundsException extends Exception {@Overridepublic String getMessage() {// TODO 自動生成的方法存根return "取款數不能為負數";}}
package exception;public class Test1 {public static void main(String[] args) {// TODO 自動生成的方法存根 Bank b=new Bank(100);try{ b.withDrawal(150);}catch (Exception e){System.out.println(e.getMessage());}try{b.withDrawal(-15);}catch(Exception e){System.out.println(e.getMessage()) ;}}}
;)
