php中的抛出异常和捕捉特定类型的异常

 1 <?php
 2 header("content-type:text/html; charset=utf-8");
 3 /**
 4  * 包裹重量异常
 5  */
 6 class HeavyParcelException extends Exception {}
 7 
 8 /**
 9  * 包裹类
10  */
11 class Parcel {
12 
13         /**
14          * 包裹寄送目的地地址
15          */
16         public $address;
17 
18         /**
19          * 包裹重量
20          */
21         public $weight;
22 }
23 
24 /**
25  * 派送员
26  */
27 class Courier {
28     
29         /** 
30          * 运送
31          */
32         public function ship(Parcel $parcel) {
33                 //check we have an address
34                 //如果包裹的目的地为空
35                 if(empty($parcel->address)) {
36                         throw new Exception(‘address not Specified(未填写地址)!‘);
37                 }   
38 
39                 //check the weight
40                 //如果重量超过5
41                 if($parcel->weight > 5) {
42                         throw new HeavyParcelException(‘Parcel exceeds courier limit(包裹超过运送上限)!‘);
43                 }   
44 
45                 //otherwise we‘re coll
46                 return true;
47         }
48 }
49 
50 $myCourier = new Courier();
51 $parcel = new Parcel();
52 //add the address if we have it 为了测试这里不填写地址
53 $parcel->weight = 7;
54 try {
55         $myCourier->ship($parcel);
56         echo "parcel shipped";
57 } catch (HeavyParcelException $e) {//捕获HeavyParcelException 不写这个异常的类型名字，就跑到普通Exception抛出去了
58         echo "Parcel weight error(重量错误): " . $e->getMessage();
59         //redirect them to choose another courier
60 } catch (Exception $e) {
61         echo "Someting went wrong(地址错误): " . $e->getMessage();
62         //exit so we don‘t try to proceed any further
63         exit;
64 }
65 echo ‘<br/>‘;
66 $a = 123;
67 echo $a;