treepanel，用servlet作为loader的url？？？

Question

页面：tree3.html

[code="java"]

Reorder TreePanel

<!-- GC -->
<!-- LIBS -->
<script type="text/javascript" src="../../adapter/ext/ext-base.js"></script>
<!-- ENDLIBS -->

<script type="text/javascript" src="../../ext-all.js"></script>

Ext.onReady(function(){ Ext.QuickTips.init(); var mytree=new Ext.tree.TreePanel({ el:"container", animate:true, title:"简单Extjs动态树", collapsible:true, enableDD:true, enableDrag:true, rootVisible:true, autoScroll:true, autoHeight:true, width:150, lines:true, //这里简简单单的loader的几行代码是取数据的,很经典哦 loader:new Ext.tree.TreeLoader({ dataUrl:"servlet/tree3" }) }); //根节点 var root=new Ext.tree.AsyncTreeNode({ id:"root", text:"控制面板", expanded:true }); mytree.setRootNode(root); mytree.render();//不要忘记render()下,不然不显示哦 })

[/code]

作为loader的url的Servlet：tree3.java

[code="java"]
package com.ext2.test;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.List;

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

import net.sf.json.JSONArray;

/**
*

• @author SUJL

• @version 1.0 Create at：2009-7-15 上午09:45:04
  */
  public class tree3 extends HttpServlet {

  public void doGet(HttpServletRequest request, HttpServletResponse response)
  throws ServletException, IOException {
  doPost(request, response);
  }

  public void doPost(HttpServletRequest request, HttpServletResponse response)
  throws ServletException, IOException {

  response.setContentType("text/html;charset=utf-8");
  PrintWriter out = response.getWriter();
  
  List<jsondata> jsdata=new ArrayList<jsondata>();
  
  for (int i = 1; i < 5; i++) {
      jsondata jd = new jsondata();
      jd.id="num"+i;
      jd.text = "节点"+i;
      jd.leaf = false;
      for (int j = 1; j < 3; j++) {
          jsondata subjd = new jsondata();
          subjd.id = "sub" + j;
          subjd.text = "子节点" + j;
          subjd.leaf = true;
          jd.children.add(subjd);
      }
      jsdata.add(jd);
  }
  
  JSONArray jsonArray = JSONArray.fromObject(jsdata);
  
  String str = jsonArray.toString();
  
  out.println(jsonArray.toString().replace("\"children\":[],", ""));
  
  out.flush();
  out.close();
  

  }

}
[/code]

jsondata.java:

[code="java"]
package com.ext2.test;

import java.util.ArrayList;
import java.util.List;

/**
*

• @author SUJL

• @version 1.0 Create at：2009-7-15 上午09:49:07
  */
  public class jsondata {
  //定义jsondata类，存放节点数据
  public String id;
  public String text;
  public boolean leaf;
  public List children=new ArrayList();//存放子节点

  public List getChildren() {
  return children;
  }
  public void setChildren(List children) {
  this.children = children;
  }
  public String getId() {
  return id;
  }
  public void setId(String id) {
  this.id = id;
  }
  public boolean isLeaf() {
  return leaf;
  }
  public void setLeaf(boolean leaf) {
  this.leaf = leaf;
  }
  public String getText() {
  return text;
  }
  public void setText(String text) {
  this.text = text;
  }

}
[/code]

已确定tree3.java输出的json数据无误，但是页面只显示根节点，各位大哥看看怎么回事。

tree3.java输出的json：

[code="java"][{"children":[{"id":"sub1","leaf":true,"text":"子节点1"},{"id":"sub2","leaf":true,"text":"子节点2"}],"id":"num1","leaf":false,"text":"节点1"},{"children":[{"id":"sub1","leaf":true,"text":"子节点1"},{"id":"sub2","leaf":true,"text":"子节点2"}],"id":"num2","leaf":false,"text":"节点2"},{"children":[{"id":"sub1","leaf":true,"text":"子节点1"},{"id":"sub2","leaf":true,"text":"子节点2"}],"id":"num3","leaf":false,"text":"节点3"},{"children":[{"id":"sub1","leaf":true,"text":"子节点1"},{"id":"sub2","leaf":true,"text":"子节点2"}],"id":"num4","leaf":false,"text":"节点4"}][/code]
[b]问题补充：[/b]
to Rowen: 能否再具体一点呢，我似乎明白你的意思，但还不是很明白。。- -！
[b]问题补充：[/b]
我把servlet改成jsp就没问题了，数据输出还是一样，跟""引好无关，servlet改成jsp是这样，几乎没什么变化哦：

tree3.jsp:

[code="java"]
<%@ page language="java" pageEncoding="utf-8"%>


<%
List jsdata=new ArrayList();

    for (int i = 1; i < 5; i++) {
        jsondata jd = new jsondata();
        jd.id="num"+i;
        jd.text = "节点"+i;
        jd.leaf = false;
        for (int j = 1; j < 3; j++) {
            jsondata subjd = new jsondata();
            subjd.id = "sub" + j;
            subjd.text = "子节点" + j;
            subjd.leaf = true;
            jd.children.add(subjd);
        }
        jsdata.add(jd);
    }

    JSONArray jsonArray = JSONArray.fromObject(jsdata);

    String json = jsonArray.toString().replace("\"children\":[],", "");

%>

<%=json%>
[/code]

Answer 1

你的根结点没有个SERVLET的结点进行绑定,用类似于下面的方法试试..
加个loader.on("beforeload", function(loader, node) {
loader.baseParams.parentid = (node.id == 'root'? "": node.id);
});