IO流，Properties基本功能和遍历

 1 import java.util.Enumeration;
 2 import java.util.Iterator;
 3 import java.util.Properties;
 4 import java.util.Set;
 5 
 6 public class PropertiesDemo {
 7     public static void main(String[] args) {
 8         Properties properties = new Properties();
 9         properties.put("zhangsan", "23");
10         properties.put("lisi", "25");
11         properties.put("wangwu", "21");
12         properties.put("zhaoliu", "27");
13         Set<String> names = properties.stringPropertyNames();
14         //使用高级for遍历
15         for(String name : names) {
16             String value = properties.getProperty(name);
17             System.out.println(name + " = " + value);
18         }
19         //使用迭代器遍历
20         Iterator<String> iterable = names.iterator();
21         while(iterable.hasNext()){
22             String key = iterable.next();
23             String value = properties.getProperty(key);
24             System.out.println(key +" = " + value);
25         }
26         //使用枚举遍历
27         Enumeration<String> enumeration = (Enumeration<String>)properties.propertyNames();
28         while(enumeration.hasMoreElements()) {
29             String key = enumeration.nextElement();
30             String value = properties.getProperty(key);
31             System.out.println(key + " = " + value);
32         }
33     }
34 }