SpringMVC文件下載

package org.hubu.utils;

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;
public class FileOperateUtils {

	//filePath代表要下載文件的路徑，realName代表下載之後的文件的名字<span style="font-family: Arial, Helvetica, sans-serif;"> </span>

	
	public static void download(HttpServletRequest request,  
            HttpServletResponse response, String filePath, String contentType,  
            String realName) throws Exception {  
        response.setContentType("text/html;charset=UTF-8");  
        request.setCharacterEncoding("UTF-8");  
        BufferedInputStream bis = null;  
        BufferedOutputStream bos = null;  
        
        String ctxPath = request.getSession().getServletContext()  
                .getRealPath("/")  ;
                 
        String downLoadPath = ctxPath + filePath;  
  
        long fileLength = new File(downLoadPath).length();  
  
        response.setContentType(contentType);
        response.setHeader("Content-disposition", "attachment; filename="  
                + new String(realName.getBytes("utf-8"), "ISO8859-1"));  
        response.setHeader("Content-Length", String.valueOf(fileLength));  
  
        bis = new BufferedInputStream(new FileInputStream(downLoadPath));  
        bos = new BufferedOutputStream(response.getOutputStream());  
        byte[] buff = new byte[2048];  
        int bytesRead;  
        while (-1 != (bytesRead = bis.read(buff, 0, buff.length))) {  
            bos.write(buff, 0, bytesRead);  
        }  
        bis.close();  
        bos.close();  
    }  
}