HashMap迭代的几种方式

1. private Hashtable<String, String> emails = new Hashtable<String, String>();  
2.   
3. //     方法一: 用entrySet()  
4. //     Iterator it = emails.entrySet().iterator();  
5. //     while(it.hasNext()){  
6. //        Map.Entry m=(Map.Entry)it.next();  
7. //         logger.info("email-" + m.getKey() + ":" + m.getValue());  
8. //     }  
9.     
10.   // 方法二：直接再循环中  
11.   for (Map.Entry<String, String> m : emails.entrySet()) {  
12.        logger.info("email-" + m.getKey() + ":" + m.getValue());  
13.    }  
14.     
15.   // 方法三：用keySet()  
16.    Iterator it = emails.keySet().iterator();  
17.   while (it.hasNext()){  
18.        String key;  
19.        key=(String)it.next();  
20.        logger.info("email-" + key + ":" + emails.get(key));  
21.    }
    

from: http://hi.baidu.com/earth_it/blog/item/833b74092e89a2c73bc763a7.html/cmtid/26b159ed8c89e2d9b21cb16a