php抛出异常与捕捉特定类型的异常详解

 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;