前台accordion布局代码：

{  
            title:'文章设置',
            items:[
                   {
                	   xtype:'treepanel',
                	   title: '文章设置',
                	   width: 200,
                	   height: 150,
                	   rootVisible: true,
                	   store:'TreeStore'//在conroller中添加到stores
                   }
            ]
}

TreeStore.js:

Ext.define('HT.store.TreeStore',{
	extend:'Ext.data.TreeStore',
	autoLoad:true,
	proxy:{  
        type:'ajax', 
        url:'tree', //请求
        reader:{  
            type:'json',  
            root:'menus' //数据
        },
        extraParams:{  
            root:''  //节点参数
        }
         
    },
    
	root: {
		text:'文章预览',
        expanded : true
    },
    listeners : {
    	//在展开前调用，发送请求，请求中应有节点信息
        'beforeexpand' : function(node,eOpts){
        	//alert(node.raw.ids);
        	this.proxy.extraParams.root = node.raw.ids;
        }
    }
    
});

struts后台代码：

TreeAtion.java:

package action;

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

import javax.servlet.http.HttpServletResponse;

import model.Menu;
import net.sf.json.JSONArray;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;

public class TreeAction extends ActionSupport {
	private List menus;	//数据
	
	private String root;	//接收节点信息
	
	public String tree(){
System.out.println("root:"+root);

		//当root为空，表示是根节点
		if("".equals(root)){
			menus = new ArrayList();

			//目录
			Menu jianjie = new Menu();
			jianjie.setText("简介");
			jianjie.setIds("jianjie");
			jianjie.setCls("file");
			jianjie.setLeaf(true);
			
			Menu diyizhang = new Menu();
			diyizhang.setText("第一章");
			diyizhang.setIds("diyizhang");
			diyizhang.setCls("folder");
			diyizhang.setLeaf(false);
			
			Menu dierzhang = new Menu();
			dierzhang.setText("第二章");
			dierzhang.setIds("dierzhang");
			dierzhang.setCls("folder");
			dierzhang.setLeaf(false);
			
			Menu zongjie = new Menu();
			zongjie.setIds("zongjie");
			zongjie.setText("总结");
			zongjie.setCls("file");
			zongjie.setLeaf(true);
			
			//根节点信息
			menus.add(jianjie);
			menus.add(diyizhang);
			menus.add(dierzhang);
			menus.add(zongjie);
		}else if("diyizhang".equals(root)){
			menus = new ArrayList();
			
			Menu diyijie = new Menu();
			diyijie.setText("第一章-第一节");
			diyijie.setCls("file");
			diyijie.setIds("diyijie");
			diyijie.setLeaf(true);
			
			Menu dierjie = new Menu();
			dierjie.setText("第一章-第二节");
			dierjie.setIds("dierjie");
			dierjie.setLeaf(true);
			
			menus.add(diyijie);
			menus.add(dierjie);
		}else if("dierzhang".equals(root)){
			menus = new ArrayList();
			
			Menu diyijie = new Menu();
			diyijie.setText("第二章-第一节");
			diyijie.setCls("file");
			diyijie.setIds("diyijie");
			diyijie.setLeaf(true);
			
			Menu dierjie = new Menu();
			dierjie.setText("第二章-第二节");
			dierjie.setIds("dierjie");
			dierjie.setLeaf(true);
			
			menus.add(diyijie);
			menus.add(dierjie);
		}
		
System.out.println(menus);

		return SUCCESS;
	}
	
	public List getMenus() {
		return menus;
	}

	public void setMenus(List menus) {
		this.menus = menus;
	}

	public String getRoot() {
		return root;
	}

	public void setRoot(String root) {
		this.root = root;
	}	
}