读取上传的文件(.doc、.docx、.txt)内容到文本，并将读取的文本返回前端

	/**
	 * 读取上传的文件(.doc、.docx、.txt)内容到文本，并将读取的文本返回前端
	 * @param file
	 * @return
	 */
	@PostMapping("/fileToText")
	@ApiOperationSupport(order = 0)
	@ApiOperation(value = "读取上传的文件", notes = "传入file")
	public R<String> fileToText(@ApiParam(value = "检测文件", required = true)@RequestParam(value="file", required=false)MultipartFile file) {
		InputStream fis = null;
		try {
			String content = "";
			if(!file.isEmpty()) {
				if(file.getSize() > 20971520) {
					return R.fail("上传的文件大小不能大于20MB，请精简后重试.");	
				}
				fis =  file.getInputStream();
				String fileName = file.getOriginalFilename().trim().toLowerCase(Locale.ENGLISH);
				if(fileName.endsWith(".doc")) {
					@SuppressWarnings("resource")
					WordExtractor extractor = new WordExtractor(fis);
					content = extractor.getText();
				} else if(fileName.endsWith(".docx")) {
					XWPFDocument document = new XWPFDocument(fis);
					@SuppressWarnings("resource")
					XWPFWordExtractor extractor = new XWPFWordExtractor(document);
					content = extractor.getText();
				} else if(fileName.endsWith(".txt")) {
					content = IOUtils.toString(fis, Charset.defaultCharset());
				} else {
					return R.fail("读取上传的文件失败:不支持的文件类型");	
				}
			}
			return R.data(content, "读取上传的文件成功");
			
		}catch(Exception e) {
			return R.fail("读取上传的文件失败:"+e.getMessage());	
		}finally {
			if (fis != null) {
			      try {
			         fis.close();
			      } catch (IOException e) {
			         e.printStackTrace();
			      }
			   }
		}
	}