Office server webs app 集成（JAVA）

这里先明确三个概念和其关系，

browser              浏览器

office server      office的软件

file server          文件管理服务器

下面上图说明下预览的时候的请求流程

简单的解释下：

 

这里注意几个问题：

1、请求地址的格式别随便改

2、请求地址中filename和返回的Base FileName保持一致会避免很多奇葩的问题存在。

3、getFile请求的时候返回的数据是流的形式返回，如果指定content-type的为

application/octet-stream。那么最好不要用RestController

4、从远程例如阿里OSS获取文件的时候计算文件大小的方法如下：

  /**
     * 从输入流中获取字节数组
     * @param inputStream
     * @return
     * @throws IOException
     */
    private static  byte[] readInputStream(InputStream inputStream) throws IOException {
        byte[] buffer = new byte[1024];
        int len = 0;
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        while((len = inputStream.read(buffer)) != -1) {
            bos.write(buffer, 0, len);
        }
        bos.close();
        return bos.toByteArray();
    }

集成代码如下：

Filter实现，集成权限校验

/**
 * 处理office的文档预览,Token处理
 * @author 大仙
 */
@Slf4j
@WebFilter(filterName = "officeFilter", urlPatterns = "/wopi/*")
public class OfficeFilter implements Filter {

    @Autowired
    private TokenCheckService authService;

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        log.info("init....");
    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest)servletRequest;
        HttpServletResponse response = (HttpServletResponse)servletResponse;
        String token = request.getParameter("access_token");
        if(StringUtils.isBlank(token)){
            fail(403,"无权限",response);
            return;
        }
        BaseUser baseUser = AccessTokenUtil.getBaseUserByToken(token);
        if(baseUser==null){
            fail(403,"无权限",response);
            return;
        }
        if(!authService.checkTokenValid(baseUser,token)){
            fail(403,"无权限",response);
            return;
        }
        log.info("执行");
        servletRequest.setAttribute("userName",baseUser.getName());
        chain.doFilter(servletRequest, servletResponse);
    }

    @Override
    public void destroy() {
        log.info("destroy....");
    }

    /**
     * 失败处理
     * @param code
     * @param message
     * @param response
     * @throws Exception
     */
    private void fail(Integer code,String message,HttpServletResponse response) throws IOException{
        response.setStatus(403);
        response.setContentType("application/json;charset=UTF-8");
        response.getWriter().write(JSONObject.toJSONString(CommonResponse.successResponse("无权限")));
    }
}

第二步：checkFileInfo的实现

 @Override
    public String getFileInfo(String fileId, HttpServletRequest request)  {
        logger.info("开始获取文件数据");
        if(StringUtils.isBlank(fileId)){
            throw new OrganException("文件ID不能为空");
        }
        fileId = fileId.substring(0,fileId.lastIndexOf("."));
        Long id = Long.parseLong(fileId);
        LessonContent lessonContent = lessonContentDao.getById(id);
        if(lessonContent==null){
            throw new OrganException("id不存在，非法请求");
        }
        String pptUrl = lessonContent.getPptUrl();
        String handUrl = lessonContent.getHandbookUrl();
        if(StringUtils.isBlank(pptUrl)&&StringUtils.isBlank(handUrl)){
            throw new OrganException("无需要预览的内容");
        }
        //获取最终预览的文件
        String fileUrl = pptUrl==null?handUrl:pptUrl;
        JSONObject result = new JSONObject();
        String BaseFileName=id+""+fileUrl.substring(fileUrl.lastIndexOf("."));
        String ownerId = "admin";
        String version = lessonContent.getCreateDate().format(DateTimeFormatter.ofPattern("yyyyMMddHHmmss"));
        Integer size = 0;
        try {
            URL url = new URL(fileUrl);
            InputStream is = url.openStream();
            byte[] bytes = readInputStream(is);
            size = bytes.length;
        }catch (Exception e){
            logger.error("读取文件出错");
        }
        return "{\"BaseFileName\":\"" + BaseFileName + "\",\"OwnerId\":\"" + ownerId + "\",\"Size\":\"" + size
                + "\",\"AllowExternalMarketplace\":\"" + true + "\",\"Version\":\"" + version + "\"}";
    }

第三步：getFile实现

 @Override
    public HttpServletResponse getFile(HttpServletResponse response, String fileId) {
        logger.info("开始获取文件数据--数据流");
        if(StringUtils.isBlank(fileId)){
            throw new OrganException("文件ID不能为空");
        }
        fileId = fileId.substring(0,fileId.lastIndexOf("."));
        Long id = Long.parseLong(fileId);
        LessonContent lessonContent = lessonContentDao.getById(id);
        if(lessonContent==null){
            throw new OrganException("id不存在，非法请求");
        }
        String pptUrl = lessonContent.getPptUrl();
        String handUrl = lessonContent.getHandbookUrl();
        if(StringUtils.isBlank(pptUrl)&&StringUtils.isBlank(handUrl)){
            throw new OrganException("无需要预览的内容");
        }
        //获取最终预览的文件
        String fileUrl = pptUrl==null?handUrl:pptUrl;
        String BaseFileName=id+""+fileUrl.substring(fileUrl.lastIndexOf("."));
        try {
            URL url = new URL(fileUrl);
            InputStream fis = url.openStream();
            String contentType = "application/octet-stream";
            byte[] buffer = readInputStream(fis);
            fis.read(buffer);
            fis.close();
            // 清空response
            response.reset();
            // 设置response的Header
            response.addHeader("Content-Disposition","attachment;filename=" + new String(BaseFileName.getBytes("utf-8"), "ISO-8859-1"));
            response.addHeader("Content-Length", "" + buffer.length);
            OutputStream toClient = new BufferedOutputStream(response.getOutputStream());
            response.setContentType(contentType);
            toClient.write(buffer);
            toClient.flush();
            toClient.close();
        }catch (Exception e){
            logger.error("读取文件出错");
        }
        return response;
    }