组合模式

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：

直接来看代码：

[java] view plain copy
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<TreeNode> getChildren(){  
    return children.elements();  
}  

}
[java] view plain copy
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。