SpringBoot中jar启动下如何读取文件路径

@GetMapping("/index")
	public String getFile() throws ioException {
		try {
			File path = new File(ResourceUtils.getURL("classpath:").getPath());
			if (!path.exists()) {
				path = new File("");
				System.err.println("path" + path.getAbsolutePath());
			}
			File upload = new File(path.getAbsolutePath(), "static/temp/");
			if (!upload.exists()) {
				boolean mkdirs = upload.mkdirs();
				String text = "drj测试";
				FileOutputStream fos = new FileOutputStream(upload.getAbsolutePath() +File.separator+ "drj.txt");
				fos.write(text.getBytes());
				fos.close();
				System.err.println("不存在" + mkdirs);
			} else {
				System.err.println(upload.getAbsolutePath());
				System.err.println("存在");
			}
			return "success";
		} catch (FileNotFoundException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
		return "error";
	}