java实现的可以无限级别添加子节点的菜单树

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：

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