Composite 组合模式

Composite 组合模式

树状结构专用模式
节点接口node，其中叶子节点leafNode和分枝节点branchNode，分枝节点聚合node泛型的list.

public class Composite {
    public static void main(String[] args) {
        BranchNode root = new BranchNode("Root");
        LeafNode leafNode1 = new LeafNode("leafNode1");
        BranchNode branchNode1 = new BranchNode("branchNode1");
        LeafNode leafNode2 = new LeafNode("leafNode2");
        LeafNode leafNode3 = new LeafNode("leafNode3");
        BranchNode branchNode2 = new BranchNode("branchNode2");
        LeafNode leafNode4 = new LeafNode("leafNode4");
        LeafNode leafNode5 = new LeafNode("leafNode5");
        root.add(leafNode1).add(branchNode1);
        branchNode1.add(leafNode2).add(leafNode3).add(branchNode2);
        branchNode2.add(leafNode4).add(leafNode5);
        tree(root,0);
    }
    public static void tree(Node node,int index){
        for (int i =0;i<index;i++){
            System.out.printf("--");
        }
        node.p();
        if(node instanceof BranchNode){
            for(Node node1: ((BranchNode) node).nodeArrayList){
                tree(node1,index+1);
            }
        }
    }
}
//节点接口类
interface Node{
    void p();
}
//叶子节点类
class LeafNode implements Node{
    String name;
    @Override
    public void p() {
        System.out.println(name);
    }
    public LeafNode(String name) {
        this.name = name;
    }
}
//分枝节点类
class BranchNode implements Node{
    String name;
    ArrayList<Node> nodeArrayList = new ArrayList<>();
    public BranchNode(String name) {
        this.name = name;
    }
    @Override
    public void p() {
        System.out.println(name);
    }
    public BranchNode add(Node node){
        nodeArrayList.add(node);
        return this;
    }
}