java下载服务器上的文件

最近在做的java项目后台需要下载服务器上的Excel模版，项目前台使用的是springMVC框架。下面是具体的代码

controller

/**
	 * 下载Excel模版
	 * @param request
	 * @param response
	 * @throws Exception
	 */
	@RequestMapping("/downloadFile.do")
	public void downloadFile(HttpServletRequest request,  
            HttpServletResponse response) throws Exception { 
		String fileName = "模版.xls";  //下载的文件名（前提：下载的文件需要存放在服务器的位置上，这里是 WebRoot/uploadFile 中）
		download.downloadFile(request, response, fileName);
	}

download类

package com.tgb.weixin.tool;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Component;

/**
 * 下载模版工具类
*    
* 项目名称：TGBWeixinNew   
* 类名称：downLoadExcel   
* 类描述：   
* 创建人：pangfan   
* 创建时间：2015-3-22 上午08:42:35   
* 修改人：pangfan   
* 修改时间：2015-3-22 上午08:42:35   
* 修改备注：   
* @version    
*
 */
@Component
public class Download {
	
	//下载模版工具类
	public void downloadFile(HttpServletRequest request,  
            HttpServletResponse response,String fileName) throws Exception {  
	  	response.setContentType("text/html;charset=UTF-8");   
	    BufferedInputStream in = null;  
	    BufferedOutputStream out = null;  
	    request.setCharacterEncoding("UTF-8");  
	    String rootpath = request.getSession().getServletContext().getRealPath("/");  
	    try {  
	        File f = new File(rootpath + "uploadFile/" + fileName);  
	        response.setContentType("application/x-excel");  
	        response.setCharacterEncoding("UTF-8");  
	        response.setHeader("Content-Disposition", "attachment; filename="+new String(fileName.getBytes("gbk"),"iso-8859-1"));  
	        response.setHeader("Content-Length",String.valueOf(f.length()));  
	        in = new BufferedInputStream(new FileInputStream(f));  
	        out = new BufferedOutputStream(response.getOutputStream());  
	        byte[] data = new byte[1024];  
	        int len = 0;  
	        while (-1 != (len=in.read(data, 0, data.length))) {  
	            out.write(data, 0, len);  
	        }  
	    } catch (Exception e) {  
	        e.printStackTrace();  
	    } finally {  
	        if (in != null) {  
	            in.close();  
	        }  
	        if (out != null) {  
	            out.close();  
	        }  
	    }  
	  
	}
}