组合模式-树状结构
1 public class TreeStructures { 2 3 public static void main(String[] args) { 4 //创建树 5 Composite root = new Composite("树根"); 6 root.Add(new Leaf("叶子A")); 7 root.Add(new Leaf("叶子B")); 8 //节点X及子节点 9 Composite composite1 = new Composite("节点X"); 10 composite1.Add(new Leaf("叶子XA")); 11 composite1.Add(new Leaf("叶子XB")); 12 //节点Y及子节点 13 Composite composite2 = new Composite("节点Y"); 14 composite2.Add(new Leaf("叶子YA")); 15 composite2.Add(new Leaf("叶子YB")); 16 //节点拼接 17 composite1.Add(composite2); 18 root.Add(composite1); 19 //显示树状结构 20 root.Show(1); 21 } 22 } 23 //树中分支节点与叶子节点的抽象父类 24 abstract class Component{ 25 //组件名称 26 protected String componentName; 27 28 public Component(String componentName) { 29 this.componentName = componentName; 30 } 31 //增加分支/叶子节点的方法 32 public abstract void Add(Component component); 33 //移除分支/叶子节点的方法 34 public abstract void Remove(Component component); 35 //按照深度显示树状结构的方法 36 public abstract void Show(int depth); 37 } 38 class Composite extends Component{ 39 40 //分支节点集合 41 private List<Component> childrenList = new ArrayList<Component>(); 42 public Composite(String componentName) { 43 super(componentName); 44 } 45 46 //增加子节点 47 @Override 48 public void Add(Component component) { 49 childrenList.add(component); 50 } 51 52 //删除子节点 53 @Override 54 public void Remove(Component component) { 55 childrenList.remove(component); 56 } 57 58 //显示子节点 59 @Override 60 public void Show(int depth) { 61 for(int i=0;i<depth;i++) { 62 System.out.print('+'); 63 } 64 System.out.print(componentName+'\n'); 65 for(int i=0;i<childrenList.size();i++) { 66 childrenList.get(i).Show(depth+2); 67 } 68 } 69 70 } 71 //树叶节点类 72 class Leaf extends Component{ 73 74 public Leaf(String componentName) { 75 super(componentName); 76 } 77 78 //增加子节点 79 @Override 80 public void Add(Component component) { 81 System.out.println("叶子节点无法添加子节点"); 82 } 83 84 //移除子节点 85 @Override 86 public void Remove(Component component) { 87 System.out.println("叶子节点无法删除节点"); 88 } 89 90 @Override 91 public void Show(int depth) { 92 for(int i=0;i<depth;i++) { 93 System.out.print('+'); 94 } 95 System.out.print(componentName+'\n'); 96 } 97 98 }
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