ツリー構造ＤＢのデータを取得する方法（ＪＡＶＡ）

public class NodeTest{

	

	static class Record{

		public Integer id;public String name;public Integer pid;

		public Record(Integer id,String name,Integer pid){

			this.id = id;this.name = name;this.pid = pid;

		}

	}



	private static final Record[] records = new Record[]{

		new Record(new Integer(1),"ROOT",null),

		new Record(new Integer(2),"NODE1",new Integer(1)),

		new Record(new Integer(3),"NODE2",new Integer(1)),

		new Record(new Integer(4),"NODE3",new Integer(1)),

		new Record(new Integer(5),"NODE1-1",new Integer(2)),

		new Record(new Integer(6),"NODE1-2",new Integer(2)),

		new Record(new Integer(7),"NODE1-3",new Integer(2)),

		new Record(new Integer(8),"NODE2-1",new Integer(3)),

		new Record(new Integer(9),"NODE3-1",new Integer(4)),

		new Record(new Integer(10),"NODE3-1-1",new Integer(9)),

		new Record(new Integer(11),"NODE3-1-2",new Integer(9)),

		new Record(new Integer(12),"NODE4",new Integer(1)),

		new Record(new Integer(13),"NODE5",new Integer(1)),

	};

	

	public static void main(String args[]){

		

		NodeParser parser = new NodeParser();

		for(int i = 0 ; i < records.length; i++){

			parser.addNodePath(records[i].id,records[i].name,records[i].pid);

		}

		

		Node root = parser.getRootNode();

		root.dump();

	}

}





class Node {



	private Node parent = null;

	private ArrayList children = new ArrayList();

	private String name;

	private Integer id;



	public Node(Integer id){

		this.id = id;

	}

	public void setName(String name){this.name = name;}

	public String getName(){return name;}

	public Integer getId(){return id;}

	public void setParent(Node parent){this.parent = parent;}

	public Node getParent(){return parent;}

	public void addChild(Node child){this.children.add(child);}

	public ArrayList getChildren(){return (ArrayList)children.clone();}



	public String getPathName(){

		return (parent != null)?

			parent.getPathName()+"/"+getName():

			getName();

	}



	public void dump(){

		System.out.println(getPathName());

		for(Iterator iter = children.iterator();iter.hasNext():wink:{

			((Node)iter.next()).dump();

		}

	}

}



class NodeParser{



	private HashMap nodemap = new HashMap();



	public void addNodePath(Integer id,String name,Integer pid){



		Node node = (Node)nodemap.get(id);

		if(node == null){

			node = new Node(id);

			nodemap.put(id,node);

		}

		node.setName(name);

		

		if(pid == null)return;

		

		Node pnode = (Node)nodemap.get(pid);

		if(pnode == null){

			pnode = new Node(pid);

			nodemap.put(pid,pnode);

		}



		node.setParent(pnode);

		pnode.addChild(node);

		

	}

	

	public Node getRootNode(){

		for(Iterator iter = nodemap.values().iterator();iter.hasNext():wink:{

			Node node =(Node)iter.next();

			if(node.getParent() == null)return node;

		}

		return null;

	}

}