public static void write(HttpServletResponse response, String text, String contentType) {
		response.setContentType(contentType);
		Writer writer = null;
		try {
			writer = response.getWriter();
			writer.write(text);
			writer.flush();
		} catch (IOException e) {
			throw new UtilException(e);
		} finally {
			IoUtil.close(writer);
		}
	}
@Test
	@Disabled
	public void writeTest() {
		HttpServletResponse response = null;
		byte[] bytes = StrUtil.utf8Bytes("地球是我们共同的家园，需要大家珍惜.");

		//下载文件
		// 这里没法直接测试，直接写到这里，方便调用；
		//noinspection ConstantConditions
		if (response != null) {
			String fileName = "签名文件.pdf";
			String contentType = "application/pdf";// application/octet-stream、image/jpeg、image/gif
			response.setCharacterEncoding(StandardCharsets.UTF_8.name()); // 必须设置否则乱码; 但是 safari乱码
			ServletUtil.write(response, new ByteArrayInputStream(bytes), contentType, fileName);
		}
	}