springMVC方法，导出/下载文件。

研究的不深，先贴代码，日后再说。

@RequestMapping(value = "/form/printContract")
		public ResponseEntity<byte[]> printContract(ContractIreportForm form)throws Exception {
			HttpHeaders headers = new HttpHeaders();

			//声明变量
			File file = null ;
			try {
				file = new File("");
				String downFileName = new String(("").getBytes("UTF-8"),"iso-8859-1");
				headers.setContentDispositionFormData("attachment", downFileName);
			    headers.setContentType(MediaType.APPLICATION_OCTET_STREAM);
			    form.setIsSuccess(SUCCESS);
			} catch (Exception e) {
				form.setIsSuccess(FAILURE);
				form.setMsg(exMsg(e));
			}
			return new ResponseEntity<byte[]>(FileUtils.readFileToByteArray(file),
	                headers, HttpStatus.CREATED);
		}