poi读取模板，填充模板数据，导出修改后的模板

public void to_exportAllAssess(){
        ArrayList<AssessResultDetail> assessResultDetailList = 查询准备填充excel的数据
        HSSFWorkbook workbook = AssessExportUtil.exportAllAssess(assessResultDetailList);
        try {
            //响应到客户端
            this.setResponseHeader(response, assessTime.getName()+"统计表.xls");
            OutputStream os = response.getOutputStream();
            workbook.write(os);
            os.flush();
            os.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    //发送响应流方法
public void setResponseHeader(HttpServletResponse response, String fileName) {
    try {
        try {
                fileName = new String(fileName.getBytes(),"ISO8859-1");
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
            }
            response.setContentType("application/octet-stream;charset=ISO8859-1");
            response.setHeader("Content-Disposition", "attachment;filename="+ fileName);
            response.addHeader("Pargam", "no-cache");
            response.addHeader("Cache-Control", "no-cache");
       } catch (Exception ex) {
           ex.printStackTrace();
    }
}

package com.*.util;

import java.io.File;
import java.io.FileInputStream;
import java.util.ArrayList;

import org.apache.poi.hssf.usermodel.HSSFWorkbook;
import org.apache.struts2.ServletActionContext;
import com.*.AssessResultDetail;

public class AssessExportUtil {
    /*
    HSSFWorkbook:是操作Excel2003以前（包括2003）的版本，扩展名是.xls
    XSSFWorkbook:是操作Excel2007的版本，扩展名是.xlsx*/
    public static HSSFWorkbook exportAllAssess(ArrayList<AssessResultDetail> assessResultDetailList) {
        //excel模板路径
        File file = new File(ServletActionContext.getServletContext().getRealPath("/WEB-INF/templet/"), "assessValue.xls");
        HSSFWorkbook workbook = null;
         if(file.exists()) {    //文件存在
             try {//创建workbook
                 workbook = new HSSFWorkbook(new FileInputStream(file));
　　　　　　　　　　//TODO 数据填充excel
             }catch(Exception e){
                 e.printStackTrace();
             }
         }
        return workbook;
    }
    
}