shh将数据导出excel

最近做一个东西，要将数据导出到excel表中，以下是代码

import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServletResponse;

import org.apache.poi.hssf.usermodel.HSSFCell;
import org.apache.poi.hssf.usermodel.HSSFCellStyle;
import org.apache.poi.hssf.usermodel.HSSFRow;
import org.apache.poi.hssf.usermodel.HSSFSheet;
import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.struts2.ServletActionContext;

import com.sun.org.apache.regexp.internal.recompile;

import entity.CRFHead;
import entity.CRFItem;

public class crfAction {
private List  dataList = new ArrayList();
public String initInfo() {
    dataList .add("1");
 dataList .add("2");
 dataList .add("3");
 dataList .add("4");
HttpServletResponse response = ServletActionContext.getResponse();
		setResponseHeader(response,"test.xls");
		try {
			exportQuery(response.getOutputStream(),dataList);
			response.getOutputStream().flush();
			response.getOutputStream().close();
		} catch (Exception e) {
			// TODO: handle exception
		}
		//数据导出后缓冲区清空
		dataList.clear();
		RESPONSE_LABEL=1;
		return "success";
}
	/**
	 * 设置输出流及输出文件的编码
	 * @param response
	 * @param filename1
	 */
	public void setResponseHeader(HttpServletResponse response,String filename1){
		try {
			response.setContentType("application/msexcel;charset=UTF-8");
			response.setHeader("content-disposition", "attachment;filename="+java.net.URLEncoder.encode(filename1, "UTF-8"));
			//System.out.println("a");
			response.addHeader("Pargam", "no-cache");
		    response.addHeader("Cache-Control", "no-cache");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
public void exportQuery(OutputStream os,List list){
/创建一个工作簿
		HSSFWorkbook workbook = new HSSFWorkbook();
		//创建单元格，并设置剧中显示
		HSSFCellStyle style = workbook.createCellStyle();//创建个表格格式
		style.setAlignment(HSSFCellStyle.ALIGN_CENTER);//设置格式为居中
//创建一个表单
		HSSFSheet sheet = workbook.createSheet("aa");
		//在sheet中添加表头第0行
		HSSFRow row = sheet.createRow((int)0);
		//设置表头
		HSSFCell cell = row.createCell((short)0);
		cell.setCellStyle(style);
		cell.setCellValue("第一列");
		cell = row.createCell((short)1);
		cell.setCellStyle(style);
		cell.setCellValue("第二列");
		cell = row.createCell((short)2);
		cell.setCellStyle(style);
		cell.setCellValue("第三列");
		cell = row.createCell((short)3);
		cell.setCellStyle(style);
		cell.setCellValue("第四列");
    row.createCell((short)0).setCellValue(list.get(0));
  row.createCell((short)1).setCellValue(list.get(1));
  row.createCell((short)2).setCellValue(list.get(2));
  row.createCell((short)3).setCellValue(list.get(3));
try{
			workbook.write(os);	
}catch(Exception e){
			e.printStackTrace();
		}	
    }
}