读取resources目录下的excel文件：

// @Component 和 @PostConstruct 配合，项目启动时执行。
@Component 
public class AppStartConfig {

    protected static final Logger logger = LoggerFactory.getLogger(AppStartConfig.class);

    @PostConstruct
    public void readStaticResources() throws IOException {
        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        Resource[] resources = resolver.getResources("classpath:\\data\\static\\*.xlsx");
        logger.info("resources:{}", (Object) resources);
        String path = "C:\\Users\\Name.last\\Desktop";
        for (Resource res : resources) {
            logger.info("开始处理文件:{}", res);
            byte[] data = readFileToByteArray(res);
            writeByteArrayToFile(data,path,res.getFilename());
            logger.info("处理文件结束!");
        }
    }

    public byte[] readFileToByteArray(Resource resource) {
        // 文件输入流（需要关闭）
        InputStream is = null;
        try {
            is = resource.getInputStream();
            // 字节数组输出流（不需要关闭）
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            byte[] buf = new byte[1024 * 2];
            int len;
            while ((len = is.read(buf)) != -1) {
                baos.write(buf, 0, len);
            }
            baos.flush();
            return baos.toByteArray();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return null;
    }

    public void writeByteArrayToFile(byte[] data, String path, String fileName) {
        // 文件输出流（需要关闭）
        OutputStream os = null;
        try {
            os = new FileOutputStream(new File(path, fileName));
            // 字节数组输入流（不需要关闭）
            InputStream is = new ByteArrayInputStream(data);
            byte[] buf = new byte[1024 * 2];
            int len;
            while ((len = is.read(buf)) != -1) {
                os.write(buf, 0, len);
            }
            os.flush();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (os != null) {
                try {
                    os.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    }

}