java学习笔记之泛型

 1 import java.util.*;
 2 
 3 public class BasicGeneric {
 4     public static void main(String[] args) {
 5         List<String> c = new ArrayList<String>();
 6         c.add("aaa");
 7         c.add("bbb");
 8         c.add("ccc");
 9         for(int i=0; i<c.size(); i++) {
10             String s = c.get(i);
11             System.out.println(s);
12         }
13         
14         Collection<String> c2 = new HashSet<String>();
15         c2.add("aaa"); c2.add("bbb"); c2.add("ccc");
16         for(Iterator<String> it = c2.iterator(); it.hasNext(); ) {
17             String s = it.next();
18             System.out.println(s);
19         }
20     }
21 }
22 
23 class MyName implements Comparable<MyName> {
24     int age;
25     
26     public int compareTo(MyName mn) {
27         if(this.age > mn.age) return 1;
28         else if(this.age < mn.age) return -1;
29         else return 0;
30     }
31 }
MyName类实现了Comparable接口，泛型后，只能和MyName进行比较