JAVA高级面试进阶训练营视频教程

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java1.7已经支持了匹配字符串

方案1.

 1 enum Animal {  
 2 
 3     dog,cat,bear;
 4 
 5      public static Animal getAnimal(String animal){  
 6 
 7        return valueOf(animal );  
 8 
 9     }   
10 
11 }
12 
13  
14 
15 public class Client {  
16 
17    public void caseAnimal(String animal){  
18 
19        switch(Animal.getAnimal(animal)){  
20 
21        case cat:  
22 
23            System.out.println("this is a cat");  
24 
25            break;  
26 
27        case dog:  
28 
29            System.out.println("this is a dog");  
30 
31            break;  
32 
33        case bear:  
34 
35            System.out.println("this is a bear");  
36 
37            break;  
38 
39        }  
40 
41    }
42 
43    
44 
45   public static void main(String[] args) {
46 
47       Client client = new Client();  
48 
49        client.caseAnimal("cat"); 
50 
51 } 
52 
53 } 

 

 方案2

 1 enum Seasons{
 2 
 3          SPRING,SUMMER,AUTUMN,WINTER
 4 
 5 }
 6 
 7 public class TestMultiInterface{
 8 
 9          public static void main(String[] args){
10 
11                    Seasons str=Seasons.SPRING;
12 
13                    switch(str.ordinal()){
14 
15                    case 0:
16 
17                    System.out.println(str.toString());
18 
19                    break;
20 
21                    case 1:
22 
23                    System.out.println(str.toString());
24 
25                    break;
26 
27                    default:
28 
29                    System.out.println("没找到");
30 
31                    }
32 
33          }
34 
35 }

 

方案3

 1 public void switchCase() { 
 2 
 3   Map<String,Integer> map=new HashMap<String, Integer>(); 
 4 
 5   map.put("中国", 1); 
 6 
 7   map.put("美国", 2); 
 8 
 9   map.put("英国", 3); 
10 
11   map.put("法国", 4); 
12 
13    
14 
15   String str="中国"; 
16 
17   switch(map.get(str)) 
18 
19   {       
20 
21    case 1: 
22 
23         System.out.println("中国"); 
24 
25         break; 
26 
27     case 2: 
28 
29         System.out.println("美国"); 
30 
31        break; 
32 
33     case 3:
34 
35         System.out.println("英国");
36 
37        break;
38 
39     case 4: 
40 
41        System.out.println("法国"); 
42 
43        break;   
44 
45    default: 
46 
47     System.out.println("default"); 
48 
49   } 
50 
51  } 

 

方案4

 1 String str1 = "aa";
 2 
 3         String[] str2 = {"bb", "aa", "cc", "aaa"};
 4 
 5         for (int i = 0; i < str2.length; ++i){
 6 
 7             switch (str1.compareTo(str2)) {
 8 
 9               case 0: System.out.println("OK");
10 
11                       break;
12 
13               default: System.out.println("Error");
14 
15                         break;
16 
17             }
18 
19         }

 

 

方案5

 1 public class Client {
 2 
 3          public Client(String animal) {
 4 
 5                    //使用String的hasCode取得字符串的哈希码，此方法要保证哈希码不重复
 6 
 7                    switch (animal.hashCode()) {
 8 
 9                    case 98262:
10 
11                             System.out.println("this is a cat");
12 
13                             break;
14 
15                    case 99644:
16 
17                             System.out.println("this is a dog");
18 
19                             break;
20 
21                    case 3019700:
22 
23                             System.out.println("this is a bear");
24 
25                             break;
26 
27                    }
28 
29          }
30 
31  
32 
33          public static void main(String[] args) {
34 
35                    Client client = new Client("bear");
36 
37          }

 

 方案6  如果是在使用简单工厂设计模式，可以考虑利用java反射技术代替switch

 1 public static UserDao createUser(){
 2   Animal animal=null;
 3   try {
 4    iu=(Animal) Class.forName(Animal接口下子类的完整类名).newInstance();
 5   }catch (Exception e) {
 6    e.printStackTrace();
 7   }
 8   return animal;
 9 
10  }

 

以上方案，有的是从网上收集来的，有的是自己原创的，因为时间过长，已经不记得从哪个地方摘抄下来的，没有注明转载的地方，十分抱歉！