excel下载模板，0KB或者乱码问题

Sptingboot项目
— maven打包，云效，docker，k8s
场景
— 导出excel模板
问题
1.乱码

2.下载为0KB，打开没有数据

模板内容

测试代码

测试方法

方法	过程	结果	问题原因
将文件直接放到服务器	使用接口下载	数据正常,排除文件问题	排除接口问题，文件问题
文件放到resource目录下	使用接口下载	下载乱码	使用相同接口下载乱码，猜测是maven编译问题
文件移出到resouce目录外	使用接口下载	下载为0KB	使用相同接口下载乱码，猜测是maven编译问题

代码

InputStream inputStream = null;ServletOutputStream servletOutputStream = null;try {//注意修改目录Resource resource = new DefaultResourceLoader().getResource("classpath:file/goods_import.xls");response.setContentType("application/force-download");response.setHeader("Content-Disposition", "attachment;fileName=" + new String("goods_import".getBytes(), StandardCharsets.ISO_8859_1)+ ".xls");inputStream = resource.getInputStream();servletOutputStream = response.getOutputStream();IOUtils.copy(inputStream, servletOutputStream);response.flushBuffer();} catch (Exception e) {log.error("下载批量上传用户模板文件错误", e);} finally {try {if (servletOutputStream != null) {servletOutputStream.close();}if (inputStream != null) {inputStream.close();}} catch (Exception e) {log.error("下载批量上传用户模板文件错误", e);}}

过程-可以跳过直接看解决办法
— 遵循网上的办法，使用字节流，设置字节大小，设置编码，都测试过一遍。

设置字节大小

   		InputStream inputStream = getClass().getClassLoader().getResourceAsStream("classpath:file/goods_import.xls");File file = new File("goods_import.xls"); // 指定下载文件的路径和名称try (OutputStream outputStream = new FileOutputStream(file)) {// 将inputStream中的数据写入到outputStream中，‌确保文件不为0KBbyte[] buffer = new byte[1024];int bytesRead;while ((bytesRead = inputStream.read(buffer)) != -1) {outputStream.write(buffer, 0, bytesRead);}} catch (IOException e) {e.printStackTrace(); // 处理异常}finally {if (file.exists()){file.delete();}}

设置字符集编码

		response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");response.setHeader("Content-Disposition", "attachment; filename=\"" + "file/goods_import.xls" + "\"");//这里设置为GBK，UTF-8都不行response.setCharacterEncoding("GBK");try (BufferedInputStream inputStream = new BufferedInputStream(ImportBusiness.class.getClassLoader().getResourceAsStream("file/goods_import.xls"));OutputStream outputStream = response.getOutputStream()) {if (inputStream == null) {// 处理文件未找到的情况response.sendError(HttpServletResponse.SC_NOT_FOUND, "File not found");return;}byte[] buffer = new byte[1024];int bytesRead;while ((bytesRead = inputStream.read(buffer)) != -1) {outputStream.write(buffer, 0, bytesRead);}outputStream.flush();} catch (IOException e) {// 处理IO异常response.sendError(HttpServletResponse.SC_INTERNAL_SERVER_ERROR, "IO error");}

使用字节流输出

/*** 模板下载*/public void downloadTemplate(HttpServletResponse response) {OutputStream out = null;InputStream in = null;ByteArrayOutputStream bos = null;String fileName = "good_import";try {// 读取模板Resource res = new ClassPathResource("classpath:file/goods_import.xls");XSSFWorkbook workbook = new XSSFWorkbook(res.getInputStream());// 转换为字节流bos = new ByteArrayOutputStream();workbook.write(bos);byte[] barray = bos.toByteArray();in = new ByteArrayInputStream(barray);response.reset();response.setContentType("application/octet-stream");response.addHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(fileName, "UTF-8") + ".xls");out = response.getOutputStream();byte[] b = new byte[1024];int len;while ((len = in.read(b)) > 0) {out.write(b, 0, len);}out.flush();} catch (Exception e) {log.error("下载模板失败", e);} finally {if (null != in) {try {in.close();} catch (IOException e) {log.error("关闭资源异常", e);}}if (null != out) {try {out.close();} catch (IOException e) {log.error("关闭资源异常", e);}}if (null != bos) {try {bos.flush();bos.close();} catch (IOException e) {log.error("关闭资源异常", e);}}}}

经测试以上方法均不行，然后考虑到jar打包会被编译，会不会是这个导致的呢。能不能忽略掉这个xls文件呢？

这里使用maven打包,使用提供的插件排除，如下

			<plugin><groupId>org.apache.maven.plugins</groupId><artifactId>maven-resources-plugin</artifactId><version>3.2.0</version><configuration><nonFilteredFileExtensions><nonFilteredFileExtension>xlsx</nonFilteredFileExtension><nonFilteredFileExtension>xls</nonFilteredFileExtension></nonFilteredFileExtensions></configuration></plugin>

重新调用接口下载，文件正常