网上大部分菜单树，都是单独用js代码来实现的，这样做的缺点是：
用户无法动态的设置菜单项，比如，超级管理员可能需要根据每个用户的权限，赋予他们不同的系统功能，不同的功能对应着不同数量的菜单项。
对于此问题，本人在他人一个js菜单的基础上，开发了一个动态的系统菜单结构树：利用java代码创建树对象，并可以
无限级别地给他添加子节点，然后在页面上生成js代码来显示树菜单。
在这儿写一个简单的Demo ,此例子共包含个文件，如下：
1、
Node.java 节点类。
2、
TreeBoot.java 树的根类。
3、
treeBean.java 页面中引入的javaBean,在此文件中实现菜单树的构建。
3、
test.jsp 测试页面。
下面提供各个文件的代码：
Node.java
package com.syw.tree;
import java.util.ArrayList;
import java.util.List;
public class Node{
//此节点下的子节点list，可以无限制 地向下扩展子节点
private List<Node> list;
//节点连接地址
private String url;
//要显示的文字
private String showName;
//指定要显示的Iframe
private String target;
//name属性
private String name;
//如果为checkBox,selected = true or false
private boolean isSelected;
//如果为checkBox,value属性值
private String value;
//节点图标，如果不给其赋值，有默认图标
private String img;
//用于标识是checkBox(input = 1)， 还是 link(input = 0)
private int input = 0;
//link构造方法
public Node(String url,String showName,String target,String img){
list = new ArrayList();
this.url = url;
this.showName = showName;
this.target = target;
this.input = 0;
this.img = img;
}
//checkBox构造方法
public Node(String showName,String name,boolean isSelected,String value,String img){
list = new ArrayList();
this.showName = showName;
this.name = name;
this.isSelected = isSelected;
this.value = value;
this.input = 1;
this.img = img;
}
//为树添加节点
public void add(Node node){
this.list.add(node);
}
//以下为所有属性的set、get方法
public List getList() {
return list;
}
public void setList(List list) {
this.list = list;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getTarget() {
return target;
}
public void setTarget(String target) {
this.target = target;
}
public String getShowName() {
return showName;
}
public void setShowName(String showName) {
this.showName = showName;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public boolean isSelected() {
return isSelected;
}
public void setSelected(boolean isSelected) {
this.isSelected = isSelected;
}
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
public int getInput() {
return input;
}
public void setInput(int input) {
this.input = input;
}
public String getImg() {
return img;
}
public void setImg(String img) {
this.img = img;
}
}
TreeBoot.java
package com.syw.tree;
import java.util.ArrayList;
import java.util.List;
public class TreeRoot {
//树的标题
private String title;
//树根节点的图标
private String titleImgPath;
//合并成的js语句内容
private String treeContent;
//树的所有子节点
private List<Node> list;
//节点计数器
private int nodeId = 0;
public TreeRoot(String title){
list = new ArrayList();
this.title = title;
}
public void add(Node node){
this.list.add(node);
}
public void setTitle(String title) {
this.title = title;
}
public void setTitleImgPath(String titleImgPath) {
this.titleImgPath = titleImgPath;
}
public void setList(List<Node> list) {
this.list = list;
}
//用递归函数取得所有树节点，并组合成js语句
private void readList(List<Node> list,int parentId){
for(Node node:list){
this.nodeId++;
if(node.getInput() == 0){
this.treeContent += "d.add("+this.nodeId+","+parentId+",'"+node.getShowName()+"','"+node.getUrl()+"','','"+node.getTarget()+"','');";
}else{
this.treeContent += "d.add("+this.nodeId+","+parentId+",'"+node.getShowName()+"<input name=\""+node.getName()+"\" type=\"checkbox\" "+(node.isSelected()?"checked=\"checked\" ":"")+"\" value=\""+node.getValue()+"\" >','','','','');";
}
if(node.getList().size()>0){
readList(node.getList(),this.nodeId);
}
}
}
//创建树，并返回js代码
public String buildTree() {
this.treeContent = "d.add(0,-1,'"+title+"');";
readList(list,0);
return this.treeContent;
}
}
treeBean.java
package com.syw.tree;
import java.util.ArrayList;
import java.util.List;
public class treeBean {
/**
* @param args
*/
public static String tree() {
Node log = new Node("","我的A Link测试","","");
log.add(new Node("http://www.baidu.com","删除日志","iframe",""));
log.add(new Node("http://www.baidu.com","添加日志","iframe",""));
log.add(new Node("http://www.baidu.com","修改日志","iframe",""));
Node checkbox = new Node("","我的checkBox测试","","");
checkbox.add(new Node("信息1","ss",false,"value1",""));
checkbox.add(new Node("信息3","ss",false,"value3",""));
checkbox.add(new Node("信息2","ss",false,"value2",""));
checkbox.add(new Node("信息4","ss",false,"value4",""));
TreeRoot blogTree = new TreeRoot("blog管理");
blogTree.add(log);
blogTree.add(checkbox);
return blogTree.buildTree();
}
}
test.jsp
<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>
<%@ page import="com.syw.tree.treeBean"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<link rel="StyleSheet" href="dtree.css" type="text/css" />
<script type="text/javascript" src="dtree.js"></script>
</head>
<body>
<div style="display:none" id="tree"><%=treeBean.tree()%></div>
<script type="text/javascript">
<!--
d = new dTree('d');
//从treeBean中获取js代码
var treecontent = document.getElementById("tree").innerHTML;
//执行代码
eval(treecontent);
document.write(d);
//-->
</script>
</div>
</body>
</html>
运行结果：
