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:

直接来看代码:


public class TreeNode {  
      
    private String name;  
    private TreeNode parent;  
    private Vector<TreeNode> children = new Vector<TreeNode>();  
      
    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;  
    }  
      
    //添加子节点  
    public void add(TreeNode node){  
        children.add(node);  
    }  
      
    //删除子节点  
    public void remove(TreeNode node){  
        children.remove(node);  
    }  
      
    //取得所有子节点  
    public Enumeration<TreeNode> 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。