接收前端界面上传文件用到的MultipartFile类

MultipartFile
MultipartFile是spring类型，代表HTML中form data方式上传的文件，包含二进制数据+文件名称。 --来自百度知道

最近有个功能是接收前端界面上传的excel文件

public static final String SEPARATOR = System.getProperty("file.separator");
public static final String DIR_FILE = System.getProperty("user.dir") + SEPARATOR + "file" + SEPARATOR;

@PostMapping("/batch/charging")
public void batchCharging(@RequestParam("file") MultipartFile file,HttpServletResponse response) {
  	String fileName = file.getOriginalFilename();
	logger.info("接收上传文件的filename:" + fileName);
	String fileFullPath = DIR_FILE + fileName;//下载文件到本地项目路径
	
	InputStream input = null;
	FileOutputStream fos = null;
	try {
		String name = fileName.substring(fileName.lastIndexOf("."));
		if(!".xls".equals(name) && !".xlsx".equals(name))
		throw new Exception("请上传Excel格式的文件");
		
		// 将接收到的Excel文件下载到文件目录中
		input = file.getInputStream();
		File f = new File(DIR_FILE);
		if (!f.exists()) {
			f.mkdirs();
		}
		fos = new FileOutputStream(fileFullPath);
		int size = 0;
		byte[] buffer = new byte[1024];
		while ((size = input.read(buffer, 0, 1024)) != -1) {
			fos.write(buffer, 0, size);
		}
	
		// 读取Excel文件内容
		//........
		
	
		// 响应信息 json字符串格式
		Map<String, Object> responseMap = new HashMap<String, Object>();
		responseMap.put("flag", true);
	
		// 生成响应的json字符串
		String jsonResponse = JSONObject.toJSONString(responseMap);
		sendResponse(jsonResponse, response);
	
	} catch (Exception e) {
		// 响应信息 json字符串格式
		Map<String, Object> responseMap = new HashMap<String, Object>();
		responseMap.put("flag", false);
		responseMap.put("errorMsg", e.getMessage());
		String jsonResponse = JSONObject.toJSONString(responseMap);
		sendResponse(jsonResponse, response);
	} finally {
		if (input != null) {
			input.close();
		}
		if (fos != null) {
			fos.close();
		}
	}

}


/**
 * 返回响应
 *
 * @throws Exception
 */
private void sendResponse(String responseString, HttpServletResponse response) throws Exception {
	response.setContentType("application/json;charset=UTF-8");
	PrintWriter pw = null;
	try {
		pw = response.getWriter();
		pw.write(responseString);
		pw.flush();
	} finally {
		IOUtils.closeQuietly(pw);
	}
}