java实现文件下载

文件下载

输出内容包含 

1.文件内容：content

2. 输出类型 contentType : application/msword

3 文件长度: contentLength： content.length

4.文件名称: 

/**
	 * 下载文件
	 * @param request
	 * @param response
	 * @throws IOException
	 * @throws InterruptedException
	 */
	public void downloadDoc(HttpServletRequest request,HttpServletResponse response) throws IOException, InterruptedException
	{
		String id=request.getParameter("id")==null?"0":request.getParameter("id");
		DocumentAtt documentAtt=documentAttDao.findById(id); //业务对象根据实际情况修改
		byte [] content=documentAtt.getFiles();
		OutputStream os=response.getOutputStream();
		InputStream is=new  ByteArrayInputStream(content); 
		response.setContentType(documentAtt.getFiletype());//可不设置
		response.setContentLength(content.length);//可不设置
		response.setHeader("Content-Disposition","attachment;filename="+new String(documentAtt.getName().getBytes("GBK"),"ISO-8859-1"));
		byte[] buffer = new byte[4000];
		int length;
		while((length = is.read(buffer)) != -1){
			  os.write(buffer,0,length);
		}
		  
		is.close();
		os.close();
	}