Ext 根据数据库返回json动态生成grid列表

package com.pbc.action;

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

import javax.servlet.http.HttpServletResponse;

import net.sf.json.JSONArray;
import net.sf.json.JSONObject;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;
import com.pbc.bean.V9News;
import com.pbc.service.Grid_Service;

public class Grid_Action extends ActionSupport {

	public String Grid_All() {
		try{
			Grid_Service grid_service=new Grid_Service();
			List vdata=grid_service.get_data();
			int tCount=vdata.size();
			JSONObject jsonContext = new JSONObject();
			jsonContext.put("totalCount", 22);
			JSONArray context = new JSONArray();
			if(tCount!=0){
				for(int i=0;i<tCount;i++){
					V9News v9News=(V9News)vdata.get(i);
					JSONObject cell = new JSONObject();
					cell.put("id",1);
					cell.put("title",v9News.getDescription());
					context.add(cell);
				}
			}
			jsonContext.put("results", context);	
			HttpServletResponse response=ServletActionContext.getResponse();
			response.setContentType("text/json; charset=gbk");
			response.setCharacterEncoding("gbk");
			PrintWriter printWriter=response.getWriter();
			printWriter.write(jsonContext.toString());
		}catch(Exception e){
			e.printStackTrace();
			return null;
		}
		return null;
		
	}

}