dtree树形菜单简例

从http://www.destroydrop.com/javascripts/tree/下载dtree.zip压缩包，解压后我们会用到dtree.js、dtree.css和img文件夹。

1.TreeInfo.java

package  com.yxx;

public   class  TreeInfo  {
    private int nodeId = -1;
    private int parentId = -1;
    private String nodeName = null;
    private String url = null;
    private String target = null;

    public int getNodeId() {
        return nodeId;
    }

    public void setNodeId(int nodeId) {
        this.nodeId = nodeId;
    }

    public int getParentId() {
        return parentId;
    }

    public void setParentId(int parentId) {
        this.parentId = parentId;
    }

    public String getNodeName() {
        return nodeName;
    }

    public void setNodeName(String nodeName) {
        this.nodeName = nodeName;
    }

    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;
    }

}

2.TreeUtil.java

package  com.yxx;

import  java.sql.Connection;
import  java.sql.DriverManager;
import  java.sql.PreparedStatement;
import  java.sql.ResultSet;
import  java.util.ArrayList;
import  java.util.List;

public   class  TreeUtil  {

    /** *//**
     * @从数据库中读取tree的信息
     * @return
     */
    public static List<TreeInfo> retrieveNodeInfos() {
        List<TreeInfo> treeInfoList = new ArrayList<TreeInfo>();
        String driverName = "com.mysql.jdbc.Driver";
        String url = "jdbc:mysql://localhost:3306/test";

        Connection connection = null;
        PreparedStatement preparedStatement = null;
        ResultSet rs = null;
        try {
            Class.forName(driverName).newInstance();
            connection = DriverManager.getConnection(url, "root", "1234");
            String sql = "select * from tree_info";
            preparedStatement = connection.prepareStatement(sql);
            rs = preparedStatement.executeQuery();

            TreeInfo treeInfo = null;
            while (rs != null && rs.next()) {
                treeInfo = new TreeInfo();
                treeInfo.setNodeId(rs.getInt(1));
                treeInfo.setParentId(rs.getInt(2));
                treeInfo.setNodeName(rs.getString(3));
                treeInfo.setUrl(rs.getString(4));
                treeInfoList.add(treeInfo);
            }
        } catch (Exception e) {
            System.out.println(e);
        }

        return treeInfoList;
    }

    /** *//**
     * @生成创建tree的脚本
     * @param treeInfoList
     * @return
     */
    public static String createTreeInfo(List<TreeInfo> treeInfoList) {
        StringBuffer contents = new StringBuffer();
        contents.append("<script type='text/javascript'>\n");
        contents.append("d = new dTree('d');\n");

        TreeInfo treeInfo = null;
        for (int i = 0; i < treeInfoList.size(); i++) {
            treeInfo = (TreeInfo) treeInfoList.get(i);
            contents.append(createOneItem(treeInfo));
        }

        contents.append("document.write(d);");
        contents.append("\n</script>");
        return contents.toString();
    }

    /** *//**
     * @生成创建一个条目的脚本
     * @param treeInfo
     * @return
     */
    public static String createOneItem(TreeInfo treeInfo) {
        StringBuffer item = new StringBuffer();
        item.append("d.add(");
        // 第一个参数，表示当前节点的ID
        item.append(treeInfo.getNodeId() + ",");
        // 第二个参数，表示当前节点的父节点的ID,根节点的值为 -1
        item.append(treeInfo.getParentId() + ",");
        // 第三个参数，节点要显示的文字
        item.append("'" + treeInfo.getNodeName() + "',");
        // 第四个参数，节点的Url
        item.append("'" + treeInfo.getUrl() + "',");
        // 第五个参数，鼠标移至该节点时节点的Title
        item.append("'" + treeInfo.getNodeName() + "',");
        // 第六个参数，节点的target
        item.append("'blank',");
        // 第七个参数，用做节点的图标,节点没有指定图标时使用默认值
        item.append("'',");
        // 第八个参数，用做节点打开的图标,节点没有指定图标时使用默认值
        item.append("'',");
        // 第九个参数，判断节点是否打开
        item.append(false);

        item.append(");\n");
        return item.toString();
    }

    /** *//**
     * @取得脚本
     * @return
     */
    public String getMenuJS() {
        String js = "";
        List<TreeInfo> treeInfoList = TreeUtil.retrieveNodeInfos();
        js = TreeUtil.createTreeInfo(treeInfoList);
        return js;
    }

    /** *//**
     * @测试生成的JS
     * @param args
     */
    public static void main(String[] args) {
        List<TreeInfo> treeInfoList = TreeUtil.retrieveNodeInfos();
        System.out.println(TreeUtil.createTreeInfo(treeInfoList));
    }
}

3.index.jsp

<! DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd" >
< jsp:useBean  id ="treeUtil"  scope ="request"  class ="com.yxx.TreeUtil"   />
< html >
     < head >
         < title > Tree </ title >
         < link  rel ="StyleSheet"  href ="dtree.css"  type ="text/css"   />
         < script  type ="text/javascript"  src ="dtree.js" ></ script >
     </ head >
     < body >
         < div  class ='dtree' >
             <% = treeUtil.getMenuJS() %>
         </ div >
     </ body >
</ html >