xml文件下载excl

package com.datamavin.util;

import java.io.BufferedInputStream;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.nio.charset.Charset;
import java.util.Map;

import javax.servlet.http.HttpServletResponse;

import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import freemarker.template.Configuration;
import freemarker.template.Template;

/**
 * 数据导出到excel表格
 * 
 * 
 */
public class ExportExcelUtil {
   /**
    * 模版导出到excel表格
    * @param templateName 模版文件名
    * @param dataMap  数据集
    * @param newFileName 导出文件名
    */
   @SuppressWarnings("resource")
   public static void exportTplExcel(String templateName, Map<String, Object> dataMap, String newFileName) {
      OutputStream myout = null;
      File outFile = null;
      Writer writer = null;
      try {
         //HttpServletRequest request = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getRequest();
         HttpServletResponse response = ((ServletRequestAttributes)RequestContextHolder.getRequestAttributes()).getResponse();
         Configuration configuration = new Configuration();
         configuration.setDefaultEncoding("utf-8");
         String path = Thread.currentThread().getContextClassLoader().getResource("/template").getPath();  
         //此处是本类Class.getResource()相对于模版文件的相对路径
         configuration.setDirectoryForTemplateLoading(new File(path));
         Template template = null;
         //String filePath = application.getRealPath("template")+ DateHandler.getSysDate() + ".xls";  
         //File outFile = new File(filePath);
         outFile = File.createTempFile("wygl_report", ".xls");
         
         template = configuration.getTemplate(templateName);
         template.setEncoding("utf-8");
         writer = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(outFile), Charset.forName("utf-8")));// 此处为输出文档编码
         template.process(dataMap, writer);
         writer.flush();

         // 设置response的编码方式
         response.setContentType("application/x-msdownload");
         // 设置附加文件名
         response.setHeader("Content-Disposition", "attachment;filename="+ new String(newFileName.getBytes("utf-8"), "iso-8859-1"));

         // 读出文件到i/o流
         FileInputStream fis = new FileInputStream(outFile);
         BufferedInputStream buff = new BufferedInputStream(fis);

         byte[] b = new byte[1024];// 相当于我们的缓存
         long k = 0;// 该值用于计算当前实际下载了多少字节
         // 从response对象中得到输出流,准备下载
         myout = response.getOutputStream();

         // 开始循环下载
         while (k < outFile.length()) {
            int j = buff.read(b, 0, 1024);
            k += j;
            // 将b中的数据写到客户端的内存
            myout.write(b, 0, j);
         }
         // 将写入到客户端的内存的数据,刷新到磁盘
         myout.flush();
         
      } catch (Exception e) {
         e.printStackTrace();
      }finally{
         try {
            if(writer!=null){writer.close();}
            if(myout!=null){myout.close();}
            //程序退出时删除临时文件
            if(outFile!=null){outFile.deleteOnExit();}
         } catch (IOException e) {
            e.printStackTrace();
         }
      }
   }
}