文件传输之ftp文件下载

         第二部分：ftp文件下载

@Controller
public class FileTransferController extends BaseController{
	
	//临时文件存放目录
	public String tempPath = FileUtil.getProjectPath()+"\\temp\\";
	
	/**
	 * 文件下载
	 * @author zheng_liming
	 * @param request
	 * @param response
	 * @return
	 */
	@RequestMapping(value = "/fileTransfer/download", method = RequestMethod.POST)
	public void download(HttpServletRequest request,HttpServletResponse response) throws Exception{
		DynamicForm dynamicForm =(DynamicForm) PlatformContext.getRequestAttribute(SystemConstants.DYNAMICFORM);
		String fileName = dynamicForm.getString("fileName");
		String filePath = dynamicForm.getString("filePath");
		File file = new File(tempPath);
		if (!file.exists()) {
			file.mkdirs();
		}
		//连接ftp
        FtpClient ftpClient = FtpUtil.connectServer(filePath);
        //将ftp上的文件下载到服务器端工程目录下
        boolean downResult = FileUtil.ftpDownload(ftpClient, fileName, tempPath+fileName);
        if(downResult){
        	//将工程目录下的文件下载到客户端
        	downFile(tempPath,fileName);
        }
        //删除工程目录下文件
        FileUtil.removeAllFile(tempPath);
        FileUtil.removeFolder(tempPath);
	}
	
	/**
	 * 将服务器上的文件下载到客户端
	 * @author zheng_liming
	 * @param filePath 文件路径
	 * @param fileName 文件名称
	 */
	public void downFile(String filePath,String fileName) throws Exception{
		FileInputStream fis = new FileInputStream(new File(filePath+fileName));
		//设置响应头和保存文件名
		HttpServletResponse response = getResponse();
		response.setContentType("APPLICATION/OCTET-STREAM");
		response.setHeader("Content-Disposition", "attachment; filename=" + URLEncoder.encode(fileName, "UTF-8"));
		//写出流信息
		int b = 0;
		PrintWriter out = response.getWriter();
		while((b=fis.read())!=-1) {
			out.write(b);
		}
		//关闭
		fis.close();
		out.close();
	}
}