Java zTree 的异步加载demo示例最近需要使用树形展示权限，所以研究了一下Java Tree，其实java中有不少Tree展示，具体有如下几种：Tree的几种开源组件：1.dtree2.ztree(国内的，api全中文，我用这个)3.JTree4.dhtmlxTree(国外的，种类齐全)，网址为:http:##以后是我找的还不错的Tree组件，还有很多！具体使用方式请参考zTreeAPI或zTree Demo（1）编写数据库脚本添加数据（2）定义一个基本权限类：Competence.java查看文本copy to clipboard打印?1.public class Competence {2.private int id; //编号3.private int pId; //父节点4.private int isParent; //是否父节点5.private String name; //节点名称6.private int open; //是否打开查看文本copy to clipboard打印? 1.//此处省略get,set方法查看文本copy to clipboard打印? 1.｝（3）创建BaseDao.java联接数据库查看文本copy to clipboard打印?2.3.import java.sql.Connection;4.import java.sql.DriverManager;5.import java.sql.PreparedStatement;6.import java.sql.ResultSet;7.import java.sql.SQLException;8.import java.sql.Statement;9.10./**11.*连接数据源12.* @authorxx13.*/14.public class BaseDao {15.static Connection conn; //创建联接16.PreparedStatement st; //预执行类17.ResultSet rs; //结果集18.19./**20.*得到连接21.* @return connnection22.*/23.public static Connection getConnection() {24.try {25.//加载驱动26.Class.forName("oracle.jdbc.driver.OracleDriver");27.try {28.//创建联接29.conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:orcl","scott", "scott");30.System.out.println("----------------打开连接-----------------");31.} catch (SQLException e) {32.System.out.println("----------------连接失败-----------------");33.e.printStackTrace();34.}35.} catch (ClassNotFoundException e) {36.System.out.println("----------------驱动加载失败-----------------");37.e.printStackTrace();38.}39.return conn;40.}41.42./**43.*关闭连接对象44.* @param rs45.* @param st46.* @param conn47.*/48.public static void closeConnection(ResultSet rs, Statement st, Connection conn) {49.try {50.if (rs != null) {51.rs.close();52.}53.if (st != null) {54.st.close();55.}56.if (conn != null && !conn.isClosed()) {57.conn.close();58.}59.System.out.println("----------------关闭连接-----------------")60.} catch (SQLException e) {61.System.out.println("----------------关闭连接失败-----------------");62.e.printStackTrace();63.}64.}65.}查看文本copy to clipboard打印?1.（4）创建测试的类Test.java查看文本copy to clipboard打印?2.3.import java.sql.Connection;4.import java.sql.SQLException;5.import java.util.ArrayList;6.import java.util.List;7.8.public class Test extends BaseDao {9.10.public List<Competence> getAllAuthorize() {11.List<Competence> authorizes = new ArrayList<Competence>();12.Connection conn = getConnection(); //得到联接13.try {14.st = conn.prepareStatement("select * from authorize2 ");15.rs = st.executeQuery(); //得到结果集16.while (rs.next()) {petence authorize = new Competence();18.authorize.setId(rs.getInt("id"));19.authorize.setpId(rs.getInt("pid"));20.authorize.setOpen(rs.getInt("open"));21.authorize.setIsParent(rs.getInt("isParent"));22.authorize.setName(rs.getString("name"));23.//添加到集合24.authorizes.add(authorize)25.}26.} catch (SQLException e) {27.System.out.println("----------------查询authorize失败-----------------")28.e.printStackTrace();29.} finally {30.closeConnection(rs, st, conn);31.}32.return authorizes;33.}34.35./**36.*拼接成json类型37.* @return38.*/39.public String getJSONData(){40.Test d = new Test();41.List<Competence> list=d.getAllAuthorize();42.StringBuffer json=new StringBuffer("[");43.String data="";44.for (int i =0; i < list.size(); i++) {45.json.append("{id:"+list.get(i).getId()+",");46.json.append("pId:"+list.get(i).getpId()+",");47.json.append("name:\""+list.get(i).getName()+"\",");48.if (list.get(i).getIsParent() !=0) {49.json.append("isParent:"+list.get(i).getIsParent()+",");50.}51.if (list.get(i).getOpen() !=0) {52.json.append("open:"+list.get(i).getOpen()+",");53.}54.data=json.substring(0,stIndexOf(","))+"},";55.json=new StringBuffer(data);56.}57.data=json.substring(0, json.length()-1)+"]";58.System.out.println(data);59.return data;60.}61.public static void main(String[] args) {62.Test demoTest=new Test()63.demoTest.getJSONData();64.}65.}（4）创建加载zTree 树的html或jsp页面asyncLoad.html查看文本copy to clipboard打印?1.<!DOCTYPE html>2.<HTML>3.<HEAD>4.<TITLE>zTree Demo</TITLE>5.<metahttp-equiv="content-type"content="text/html; charset=UTF-8">6.<linkrel="stylesheet"href="../css/demo.css"type="text/css">7.<!--必须文件zTreeStyle.css、jquery.ztree.core-x.js、jquery-x.min.js -->8.<linkrel="stylesheet"href="../css/zTreeStyle/zTreeStyle.css"type="text/css">9.<scripttype="text/javascript"src="../js/jquery-1.4.4.min.js"></script>10.<scripttype="text/javascript"src="../js/jquery.ztree.core-3.5.js"></script>11.<scriptlanguage="JavaScript">12. var setting= {13.async :{14.enable :true, //设置zTree是否开启<strong>异步</strong>加载模式15. url :"asyncData/loadData2.jsp", // Ajax 获取数据的URL 地址16.autoParam :[ "id" ] //<strong>异步</strong>加载时自动提交父节点属性的参数,假设父节点node= {id:1, name:"test"}，<strong>异步</strong>加载时，提交参数zId=117.},18.data:{ //必须使用data19.simpleData :{20.enable :true,21. idKey :"id", // id编号命名默认22.pIdKey :"pId", //父id编号命名默认23.rootPId :0 //用于修正根节点父节点数据，即pIdKey 指定的属性值24.}25.},26.//回调函数27.callback :{28.onClick :function(event, treeId, treeNode, clickFlag) {29.//判断是否父节点30.if(!treeNode.isParent){31. alert("treeId自动编号：" + treeNode.tId + ",节点id是：" + treeNode.id + ",节点文本是：" + );32.}33.},34.//捕获<strong>异步</strong>加载出现异常错误的事件回调函数和成功的回调函数35.onAsyncError :zTreeOnAsyncError,36.onAsyncSuccess :function(event, treeId, treeNode, msg){37.38.}39.}40.};41.42.//加载错误提示43. function zTreeOnAsyncError(event, treeId, treeNode, XMLHttpRequest, textStatus, errorThrown) {44.alert("加载错误：" + XMLHttpRequest);45.};46.47.//过滤函数48.function filter(treeId, parentNode, childNodes) {49.if (!childNodes)50.return null;51. for ( var i=0,l=childNodes.length; i<l; i++) {52.childNodes[i].name=childNodes[i].name.replace(/\.n/g, '.');53.}54.return childNodes;55.}56.57.//渲染58.$(document).ready(function() {59.$.fn.zTree.init($("#treeDemo"), setting);60.});61.</script>62.</HEAD>63.<BODY>64.<div>65.<ulid="treeDemo"class="ztree"></ul>66.</div>67.</BODY>68.</HTML>（5）创建一个接收的Servlet，本测试使用jsp代替loadData.jsp查看文本copy to clipboard打印?1.<%@ pagelanguage="java"import="java.util.*"pageEncoding="utf-8"%>3.4.<%5. String id=request.getParameter("id"); //父节点编号6.System.out.print("得到的节点id："+id);7. Test demo=newTest();8. String json=demo.getJSONData();9.out.print(json);10.%>注：json数据最终会被拼接成array的形式，如下结果：xx即可显示查看文本copy to clipboard打印?1.[{id:100,pId:0,name:"父节点",isParent:1,open:1},{id:101,pId:100,name: "叶子节点—1",isParent:1},{id:102,pId:100,name: "叶子节点—2",isParent:1},{id:103,pId:100,name: "叶子节点—3",isParent:1},{id:104,pId:0,name:"NB的父节点",isParent:1,open:1},{id:105,pId:104,name:"xx节点2—1",isParent:1},{id:106,pId:104,name:"叶子节点2—2",isParent:1},{id:107,pId:104,name: "叶子节点2—3"},{id:108,pId:0,name:"郁闷的父节点",isParent:1},{id:109,pId:108,name: "叶子节点3—1"},{id:110,pId:108,name:"叶子节点3—2"},{id:111,pId:108,name:"叶子节点3—3"},{id:112,pId:101,name:"秘书"},{id:113,pId:101,name:"行政"},{id:114,pId:102,name:"助理"},{id:115,pId:102,name:"保安"},{id:116,pId:103,name:"销售"},{id:117,pId:103,name:"前台"},{id:118,pId:103,name:"主管"},{id:119,pId:105,name:"卫生"},{id:120,pId:106,name:"人事"}]效果如图这里的小测试使用了子父节点同时加载完毕效果，加载完毕后，单击父节点不会再次访问数据库，会从缓存中加载。