異常3

建立Bank類，類中有變數double balance表示存款,Bank類的構造方法能初始化餘額，Bank類中有存款的方法cunKuan(double  balance)，取款的發方法withDrawal(double dAmount),當取款的數額大於存款時,拋出InsufficientFundsException,取款數額為負數，拋出NagativeFundsException,當用方法withdrawal(150)，withdrawal(-15)時會拋出自定義異常。

 1 public class Bank {
 2     double yu_e;
 3     double balance;
 4 
 5     Bank(double yu_e) {
 6         this.yu_e = yu_e;
 7         System.out.println("賬戶內餘額："+this.yu_e+"元");
 8     }
 9 
10     void cunKuan(double balance) throws Exception {
11         if(balance<0){
12             throw new Exception("存款不能為負");
13         }
14         yu_e += balance;
15     }
16 
17     void withDrawal(double dAmount) throws Exception {
18         if(dAmount>yu_e){
19             throw new Exception("InsufficientFundsException，餘額不足");
20         }else if (dAmount<0){
21             throw new Exception("NagativeFundsException,取款值為負");
22         }
23         yu_e -= dAmount;
24     }
25 
26     public static void main(String[] args) {
27 
28         Bank b = new Bank(10);
29         try {
30             b.cunKuan(-100);
31         } catch (Exception e) {
32             e.printStackTrace();
33         }  
34         
35         try {
36             b.withDrawal(150);
37         } catch (Exception e) {
38             e.printStackTrace();
39         }
40         
41         try {
42             b.withDrawal(-15);
43         } catch (Exception e) {
44             e.printStackTrace();
45         }
46 
47         System.out.println("存款餘額"+b.yu_e+"元");
48 
49     }
50 
51 }

運行：