js dtree的简单应用

前几天在javaeye上看到有这样一个帖子（http://www.iteye.com/topic/245728），今天把我的解决代码贴在我的blog中。数据库是这样的记录
year，month，title
2004 3      第一条标题
2004 5      第二条标题
2005 6      第三条标题
2005 6      第四条标题
2002 6      第五条标题
要求在前台以年，月，日，树状展示，比如点击2004，然后出来下面所有的月，在点击月，出来下面所有的标题

这里算是做一个dtree的简单应用吧。

package app;

public class Title {
	private int year;
	private int month;
	private String name;
	
	public Title() {
	}
	
	public Title(int year, int month, String name) {
		this.year = year;
		this.month = month;
		this.name = name;
	}
	
	public int getYear() {
		return year;
	}
	public void setYear(int year) {
		this.year = year;
	}
	public int getMonth() {
		return month;
	}
	public void setMonth(int month) {
		this.month = month;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
}

 

package app;

public class TreeDaoImpl {
	
	public Title[] queryAllTitle() {
		Title[] titles = new Title[5];
		titles[0] = new Title(2004, 3, "第一条标题");
		titles[1] = new Title(2004, 5, "第二条标题");
		titles[2] = new Title(2005, 6, "第三条标题");
		titles[3] = new Title(2005, 6, "第四条标题");
		titles[4] = new Title(2002, 6, "第五条标题");
		
		return titles;
	}
}

 

package app;

import java.util.*;

public class Node {
	private Object data;
	private Node parent;
	private List<Node> children;
	
	public Node() {
		children = new ArrayList<Node>();
	}
	
	public Node(Object data, Node parent) {
		this.data = data;
		this.parent = parent;
		children = new ArrayList<Node>();
	}
	
	public boolean hasChildren() {
		return children.size() != 0;
	}
	
	public boolean containChildData(Object data) {
		return queryChildByData(data) != null;
	}
	
	public Node queryChildByData(Object data) {
		Node r = null;
		for(Node node : children) {
			if(node.getData().equals(data)) {
				r = node;
				break;
			}
		}
		
		return r;
	}
	
	public void addChild(Node node) {
		children.add(node);
	}
	
	public Object getData() {
		return data;
	}

	public void setData(Object data) {
		this.data = data;
	}

	public Node getParent() {
		return parent;
	}

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

	public List<Node> getChildren() {
		return children;
	}

	public void setChildren(List<Node> children) {
		this.children = children;
	}
}

 

package app;

public class MenuTreeBuilder {
	
	public MenuTreeBuilder(TreeDaoImpl dao) {
		this.dao = dao;
		idx = 1;
		buffer = new StringBuffer();
	}
	
	public void generateMenuTree(String rootName) {
		
		root = new Node(rootName, null);
		
		Title[] titles = dao.queryAllTitle();
		for(int i = 0; titles != null && i < titles.length; i++) {
			
			Node yearNode = null;
			Node monthNode = null;
			String year = String.valueOf(titles[i].getYear());
			String month = String.valueOf(titles[i].getMonth());
			
			if( !root.containChildData(year) ) {
				yearNode = new Node(year, root);
				root.addChild(yearNode);
			} else {
				yearNode = root.queryChildByData(year);
			}
			
			if( !yearNode.containChildData(month) ) {
				monthNode = new Node(month, yearNode);
				yearNode.addChild(monthNode);
			} else {
				monthNode = yearNode.queryChildByData(month);
			}
			
			monthNode.addChild(new Node(titles[i].getName(), monthNode));
		}

	}
	
	public String generateJS() {
		
		buffer.append("d = new dTree('d');\n");
		buffer.append("d.add(" + idx + "," + "-1, '" + root.getData().toString() + "');\n");
		
		privateGenerateJs(root);		
		return buffer.toString();
	}
	
	private void privateGenerateJs(Node parentNode) {
		int rootIdx = idx;
		for(int i = 0; i < parentNode.getChildren().size(); i++) {
			Node node = parentNode.getChildren().get(i);
			++idx;
			buffer.append("d.add(" + idx + "," + rootIdx + ", '" + node.getData().toString() + "');\n");
			
			privateGenerateJs(node);
		}
	}
		
	private TreeDaoImpl dao;
	private Node root;
	private int idx;
	private StringBuffer buffer;
}

 

package app;

public class Test {
	
	public static void main(String[] args) {
		TreeDaoImpl dao = new TreeDaoImpl();
		MenuTreeBuilder mtb = new MenuTreeBuilder(dao);
		mtb.generateMenuTree("年份");
		String s = mtb.generateJS();
		System.out.println(s);
	}
}

 最后，把程序生成的JS替换使用dtree的例子中的部分JS即可。当然，实际应用可能不是这个样子，这里只是做个例子，这个程序可以根据自己的需要更改。程序控制台输出

d = new dTree('d');
d.add(1,-1, '年份');
d.add(2,1, '2004');
d.add(3,2, '3');
d.add(4,3, '第一条标题');
d.add(5,2, '5');
d.add(6,5, '第二条标题');
d.add(7,1, '2005');
d.add(8,7, '6');
d.add(9,8, '第三条标题');
d.add(10,8, '第四条标题');
d.add(11,1, '2002');
d.add(12,11, '6');
d.add(13,12, '第五条标题');

 

附件中的图片是运行效果截图：