JQuery ztree 异步加载实例讲解

本来要做一个文件目录浏览界面，需要遍历所有的文件和目录，很显然一次性读取时很费时费力的一件事情。

因此就需要做异步加载....

准备工作：

1下载 JQuery ZTree

复制其中的JS和CSS即可，其实没必要引那么多，用什么引什么就可以。

2 需要fastJSON,用来转换JSON对象

　　我下载JAR包后，引入到Eclipse中总是报找不到class错误。

　　解决办法：把jar包放在WEB-INF/lib下即可。

代码实例：

index.jsp

<%@ page language="java" contentType="text/html; charset=utf-8"
 pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
 <link rel="stylesheet" href="resources/css/demo.css" type="text/css">
 <link rel="stylesheet" href="resources/css/zTreeStyle/zTreeStyle.css" type="text/css">
 <script type="text/javascript" src="resources/js/jquery-1.4.4.min.js"></script>
 <script type="text/javascript" src="resources/js/jquery.ztree.core-3.5.js"></script>

</head>
<body>
 <div class="zTreeDemoBackground left">
  <ul id="treeDemo" class="ztree"></ul>
 </div>
 <SCRIPT type="text/javascript">
  var setting = {
    data: {
     simpleData: {
      enable: true
     }
    } ,
    async: {
     enable: true,
     url:"/TestZTree/test",
     autoParam:["id", "name", "level"],
     otherParam:{"otherParam":"zTreeAsyncTest"},
     dataFilter: filter
    }
  };
  function filter(treeId, parentNode, childNodes) {
   if (!childNodes) return null;
   for (var i=0, l=childNodes.length; i<l; i++) {
    childNodes[i].name = childNodes[i].name.replace(/\.n/g, '.');
   }
   return childNodes;
  }
  var zNodes =[
   { id:1, pId:0, name:"parentNode 1", open:true},
   { id:11, pId:1, name:"parentNode 11",isParent:true},
   { id:111, pId:11, name:"leafNode 111"},
   { id:112, pId:11, name:"leafNode 112"},
   { id:12, pId:1, name:"parentNode 12",isParent:true},
   { id:121, pId:12, name:"leafNode 121"},
   { id:13, pId:1, name:"parentNode 13", isParent:true},
   { id:2, pId:0, name:"parentNode 2", isParent:true}
  ]; 

  $(document).ready(function(){
   $.fn.zTree.init($("#treeDemo"), setting, zNodes);
  });
 </SCRIPT>
</body>
</html>

testServlet.java

package com.test;

import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;

public class testServlet extends HttpServlet{
 @Override
 public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  doPost(request, response);
 } 

 @Override
 public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
  String id = request.getParameter("id");
  String name = request.getParameter("name");
  String level = request.getParameter("level");
  String otherParam = request.getParameter("otherParam");
  System.out.println(id + "|" + name + "|" + level + "|" + otherParam); 

  List<HashMap<String,Object>> list = new ArrayList<HashMap<String,Object>>();
  for(int i = 0; i < 5; i++){
   HashMap<String,Object> hm = new HashMap<String,Object>(); //最外层，父节点
   hm.put("id",id+i);//id属性 ，数据传递
   hm.put("name", id+i); //name属性，显示节点名称
   hm.put("pId", id); 

   list.add(hm);
  }
  response.getWriter().write(JSON.toJSONString(list));
 }
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5"
 xmlns="http://java.sun.com/xml/ns/javaee"
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
 http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">
 <display-name></display-name>
 <servlet>
 <servlet-name>testServlet</servlet-name>
 <servlet-class>com.test.testServlet</servlet-class>
 </servlet>

 <servlet-mapping>
 <servlet-name>testServlet</servlet-name>
 <url-pattern>/test</url-pattern>
 </servlet-mapping>

 <welcome-file-list>
 <welcome-file>index.jsp</welcome-file>
 </welcome-file-list>
</web-app>

效果图：

更多关于ztree控件的内容，请参考专题《jQuery插件ztree使用汇总》

以上就是关于jquery异步加载，希望对大家学习jquery程序设计有所帮助。