合成模式

 1 import java.util.ArrayList;
 2 import java.util.List;
 3 
 4 //抽象构建接口
 5 interface Component{
 6     public void printNode(String str);
 7 }
 8 
 9 //树枝类
10 class Composite implements Component{
11 
12     private List<Component> childs = new ArrayList<Component>();
13     private String name;
14     
15     public Composite(String name){
16         this.name = name;
17     }
18     
19     public void add(Component child){
20         childs.add(child);
21     }
22     
23     public void remove(int index){
24         childs.remove(index);
25     }
26     
27     public List<Component> getChild(){
28         return childs;
29     }
30     
31     @Override
32     public void printNode(String str) {
33         System.out.println(str + "+" + name);
34         if(childs != null){
35             str += " ";
36             for(Component c: childs)
37                 c.printNode(str);
38         }
39     }
40     
41 }
42 
43 //树叶类
44 class Leaf implements Component{
45 
46     private String name;
47     
48     public Leaf(String name){
49         this.name = name;
50     }
51     
52     @Override
53     public void printNode(String str) {
54         System.out.println(str + "-" + name);
55     }
56     
57 }
58 
59 public class MyTest {
60 
61     /**
62      * @param args
63      */
64     public static void main(String[] args) {
65         Composite root = new Composite("根");
66         Composite c1 = new Composite("树枝1");
67         Composite c2 = new Composite("树枝2");
68         
69         Leaf leaf1 = new Leaf("树叶1");
70         Leaf leaf2 = new Leaf("树叶2");
71         Leaf leaf3 = new Leaf("树叶3");
72         
73         root.add(c1);
74         root.add(c2);
75         c1.add(leaf1);
76         c1.add(leaf2);
77         c2.add(leaf3);
78     }
79 
80 }