设计模式读书笔记-组合模式

• 定义：将对象组合成树形结构以表示“部分-整体”的层次结构，使得用户对单个对象和组合对象的使用具有一致性。
• 代码：

public abstract class Node {

    private String nodeName;
    private String nodeId;

    public Node(String nodeName,String nodeId) {
        this.nodeId = nodeId;
        this.nodeName = nodeName;
    }

    public String getNodeInfo(){
        String nodeInfo = "节点名称："+nodeName+"  节点Id："+nodeId;
        return nodeInfo;
    }

}



public class BranchNode extends Node{

    private List<Node> subNodeList = new ArrayList<Node>();


    public BranchNode(String branchNodeName,String branchNodeId) {
        super(branchNodeName,branchNodeId);
    }

    public void addSubNode(Node subNode){
        subNodeList.add(subNode);
    }

    public List<Node> getSubNodeList(){
        return subNodeList;
    }
}



public class LeafNode extends Node{
    public LeafNode(String leafNodeName,String leafNodeId) {
        super(leafNodeName,leafNodeId);
    }
}



public class Client {

    public static void main(String[] args){
        BranchNode root = buildTree();
        System.out.println(getTreeInfo(root));
    }

    public static BranchNode buildTree(){
        //将根节点对象生产出来---------------------------------------------
        BranchNode root = new BranchNode("机构人员树","-1");

        //将一级机构生产出来----------------------------------------------
        BranchNode firstOrg1 = new BranchNode("北京市","1");

        //将二级机构生产出来-----------------------------------------------
        BranchNode secondOrg1 = new BranchNode("海淀区","101");
        BranchNode secondOrg2 = new BranchNode("大兴区","102");
        BranchNode secondOrg3 = new BranchNode("丰台区","103");

        //将三级人员生产出来------------------------------------------------
        LeafNode person1 = new LeafNode("北京海淀人1","10101");
        LeafNode person2 = new LeafNode("北京海淀人2","10102");
        LeafNode person3 = new LeafNode("北京大兴人1","10201");
        LeafNode person4 = new LeafNode("北京丰台人1","10301");

        //组装---------------------------------------------------------
        secondOrg1.addSubNode(person1);
        secondOrg1.addSubNode(person2);
        secondOrg2.addSubNode(person3);
        secondOrg3.addSubNode(person4);

        firstOrg1.addSubNode(secondOrg1);
        firstOrg1.addSubNode(secondOrg2);
        firstOrg1.addSubNode(secondOrg3);

        root.addSubNode(firstOrg1);

        return root;
    }

    public static String getTreeInfo(BranchNode branchNode){
        String result = branchNode.getNodeInfo()+"\n";
        List<Node> subList = branchNode.getSubNodeList();

        for(int i=0;i<subList.size();i++){
            Node node = subList.get(i);
            result += node.getNodeInfo()+"\n";
            if(node instanceof BranchNode){
                result += getTreeInfo((BranchNode)node)+"\n";
            }
        }
        return result;
    }
}

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