组合模式有时又叫部分-整体模式在处理类似树形结构的问题时比较方便,看看关系图:
public class TreeNode { private String name; private TreeNode parent; private Vectorchildren = new Vector (); public TreeNode(String name){ this.name = name; } public String getName() { return name; } public void setName(String name) { this.name = name; } public TreeNode getParent() { return parent; } public void setParent(TreeNode parent) { this.parent = parent; } //添加孩子节点 public void add(TreeNode node){ children.add(node); } //删除孩子节点 public void remove(TreeNode node){ children.remove(node); } //取得孩子节点 public Enumeration getChildren(){ return children.elements(); }}
public class Tree { TreeNode root = null; public Tree(String name) { root = new TreeNode(name); } public static void main(String[] args) { Tree tree = new Tree("A"); TreeNode nodeB = new TreeNode("B"); TreeNode nodeC = new TreeNode("C"); nodeB.add(nodeC); tree.root.add(nodeB); System.out.println("build the tree finished!"); }}
使用场景:将多个对象组合在一起进行操作,常用于表示树形结构中,例如二叉树,数等。