JAVA编程思想（第四版）学习笔记----11.4 容器的打印

 1 import static java.lang.System.out;
 2 
 3 import java.util.ArrayList;
 4 import java.util.Collection;
 5 import java.util.HashMap;
 6 import java.util.HashSet;
 7 import java.util.LinkedHashMap;
 8 import java.util.LinkedHashSet;
 9 import java.util.LinkedList;
10 import java.util.Map;
11 import java.util.TreeMap;
12 import java.util.TreeSet;
13 
14 public class ContainerFramework {
15 
16     static Collection fill(Collection<String> collection) {
17         collection.add("rat");
18         collection.add("cat");
19         collection.add("dog");
20         collection.add("dog");
21         return collection;
22     }
23 
24     static Map fill(Map<String, String> map) {
25         map.put("rat", "Fuzzy");
26         map.put("cat", "Rags");
27         map.put("dog", "Bosco");
28         map.put("dog", "Spot");
29         return map;
30     }
31     public static void main(String[] args) {
32         out.println(fill(new ArrayList<String>()));
33         out.println(fill(new LinkedList<String>()));
34         out.println(fill(new HashSet<String>()));
35         out.println(fill(new TreeSet<String>()));
36         out.println(fill(new LinkedHashSet<String>()));
37         out.println(fill(new HashMap<String, String>()));
38         out.println(fill(new TreeMap<String, String>()));
39         out.println(fill(new LinkedHashMap<String, String>()));
40     }
41 }

[rat, cat, dog, dog]
[rat, cat, dog, dog]
[cat, dog, rat]
[cat, dog, rat]
[rat, cat, dog]
{cat=Rags, dog=Spot, rat=Fuzzy}
{cat=Rags, dog=Spot, rat=Fuzzy}
{rat=Fuzzy, cat=Rags, dog=Spot}