SpringBoot项目：RedisTemplate实现轻量级消息队列

作者：wangzaiplus

原文链接：

http://www.jianshu.com/p/0c684076367e

背景

公司项目有个需求, 前端上传excel文件, 后端读取数据、处理数据、返回错误数据, 最简单的方式同步处理, 客户端上传文件后一直阻塞等待响应, 但用户体验无疑很差, 处理数据可能十分耗时, 没人愿意傻等, 由于项目暂未使用ActiveMQ等消息队列中间件, 而redis的lpush和rpop很适合作为一种轻量级的消息队列实现, 所以用它完成此次功能开发

一、本文涉及知识点

• excel文件读写--阿里easyexcel sdk

• 文件上传、下载--腾讯云对象存储

• 远程服务调用--restTemplate

• 生产者、消费者--redisTemplate leftPush和rightPop操作

• 异步处理数据--Executors线程池

• 读取网络文件流--HttpClient

• 自定义注解实现用户身份认证--JWT token认证, 拦截器拦截标注有@LoginRequired注解的请求入口

当然, Java实现咯

涉及的知识点比较多, 每一个知识点都可以作为专题进行学习分析, 本文将完整实现呈现出来, 后期拆分与小伙伴分享学习

二、项目目录结构

说明: 数据库DAO层放到另一个模块了, 不是本文重点

三、主要maven依赖

1.easyexcel

<easyexcel-latestVersion>1.1.2-beta4</easyexcel-latestVersion>

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>easyexcel</artifactId>
            <version>${easyexcel-latestVersion}</version>
        </dependency>

2.JWT

        <dependency>
            <groupId>io.jsonwebtoken</groupId>
            <artifactId>jjwt</artifactId>
            <version>0.7.0</version>
        </dependency>

3.redis

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-redis</artifactId>
            <version>1.3.5.RELEASE</version>
        </dependency>

4.腾讯cos

        <dependency>
            <groupId>com.qcloud</groupId>
            <artifactId>cos_api</artifactId>
            <version>5.4.5</version>
        </dependency>

四、流程

• 用户上传文件

• 将文件存储到腾讯cos

• 将上传后的文件id及上传记录保存到数据库

• redis生产一条导入消息, 即保存文件id到redis

• 请求结束, 返回"处理中"状态

• redis消费消息

• 读取cos文件, 异步处理数据

• 将错误数据以excel形式上传至cos, 以供用户下载, 并更新处理状态为"处理完成"

• 客户端轮询查询处理状态, 并可以下载错误文件

• 结束

五、实现效果

1.上传文件

2.数据库导入记录

3.导入的数据

4.下载错误文件

5.错误数据提示

6.查询导入记录

六、代码实现

1、导入excel控制层

    @LoginRequired
    @RequestMapping(value = "doImport", method = RequestMethod.POST)
    public JsonResponse doImport(@RequestParam("file") MultipartFile file, HttpServletRequest request) {
        PLUser user = getUser(request);
        return orderImportService.doImport(file, user.getId());
    }

2、service层

    @Override
    public JsonResponse doImport(MultipartFile file, Integer userId) {
        if (null == file || file.isEmpty()) {
            throw new ServiceException("文件不能为空");
        }

        String filename = file.getOriginalFilename();
        if (!checkFileSuffix(filename)) {
            throw new ServiceException("当前仅支持xlsx格式的excel");
        }

        // 存储文件
        String fileId = saveToOss(file);
        if (StringUtils.isBlank(fileId)) {
            throw new ServiceException("文件上传失败, 请稍后重试");
        }

        // 保存记录到数据库
        saveRecordToDB(userId, fileId, filename);

        // 生产一条订单导入消息
        redisProducer.produce(RedisKey.orderImportKey, fileId);

        return JsonResponse.ok("导入成功, 处理中...");
    }

    /**
     * 校验文件格式
     * @param fileName
     * @return
     */
    private static boolean checkFileSuffix(String fileName) {
        if (StringUtils.isBlank(fileName) || fileName.lastIndexOf(".") <= 0) {
            return false;
        }

        int pointIndex = fileName.lastIndexOf(".");
        String suffix = fileName.substring(pointIndex, fileName.length()).toLowerCase();
        if (".xlsx".equals(suffix)) {
            return true;
        }

        return false;
    }

   /**
     * 将文件存储到腾讯OSS
     * @param file
     * @return
     */
    private String saveToOss(MultipartFile file) {
        InputStream ins = null;
        try {
            ins = file.getInputStream();
        } catch (IOException e) {
            e.printStackTrace();
        }

        String fileId;
        try {
            String originalFilename = file.getOriginalFilename();
            File f = new File(originalFilename);
            inputStreamToFile(ins, f);
            FileSystemResource resource = new FileSystemResource(f);

            MultiValueMap<String, Object> param = new LinkedMultiValueMap<>();
            param.add("file", resource);

            ResponseResult responseResult = restTemplate.postForObject(txOssUploadUrl, param, ResponseResult.class);
            fileId = (String) responseResult.getData();
        } catch (Exception e) {
            fileId = null;
        }

        return fileId;
    }

3、redis生产者

@Service
public class RedisProducerImpl implements RedisProducer {

    @Autowired
    private RedisTemplate redisTemplate;

    @Override
    public JsonResponse produce(String key, String msg) {
        Map<String, String> map = Maps.newHashMap();
        map.put("fileId", msg);
        redisTemplate.opsForList().leftPush(key, map);
        return JsonResponse.ok();
    }

}

4、redis消费者

@Service
public class RedisConsumer {

    @Autowired
    public RedisTemplate redisTemplate;

    @Value("${txOssFileUrl}")
    private String txOssFileUrl;

    @Value("${txOssUploadUrl}")
    private String txOssUploadUrl;

    @PostConstruct
    public void init() {
        processOrderImport();
    }

    /**
     * 处理订单导入
     */
    private void processOrderImport() {
        ExecutorService executorService = Executors.newCachedThreadPool();
        executorService.execute(() -> {
            while (true) {
                Object object = redisTemplate.opsForList().rightPop(RedisKey.orderImportKey, 1, TimeUnit.SECONDS);
                if (null == object) {
                    continue;
                }
                String msg = JSON.toJSONString(object);
                executorService.execute(new OrderImportTask(msg, txOssFileUrl, txOssUploadUrl));
            }
        });
    }

}

5、处理任务线程类

public class OrderImportTask implements Runnable {
    public OrderImportTask(String msg, String txOssFileUrl, String txOssUploadUrl) {
        this.msg = msg;
        this.txOssFileUrl = txOssFileUrl;
        this.txOssUploadUrl = txOssUploadUrl;
    }
}

    /**
     * 注入bean
     */
    private void autowireBean() {
        this.restTemplate = BeanContext.getApplicationContext().getBean(RestTemplate.class);
        this.transactionTemplate = BeanContext.getApplicationContext().getBean(TransactionTemplate.class);
        this.orderImportService = BeanContext.getApplicationContext().getBean(OrderImportService.class);
    }

    @Override
    public void run() {
        // 注入bean
        autowireBean();

        JSONObject jsonObject = JSON.parseObject(msg);
        String fileId = jsonObject.getString("fileId");

        MultiValueMap<String, Object> param = new LinkedMultiValueMap<>();
        param.add("id", fileId);

        ResponseResult responseResult = restTemplate.postForObject(txOssFileUrl, param, ResponseResult.class);
        String fileUrl = (String) responseResult.getData();
        if (StringUtils.isBlank(fileUrl)) {
            return;
        }

        InputStream inputStream = HttpClientUtil.readFileFromURL(fileUrl);
        List<Object> list = ExcelUtil.read(inputStream);
        process(list, fileId);
    }

    /**
     * 将文件上传至oss
     * @param file
     * @return
     */
    private String saveToOss(File file) {
        String fileId;
        try {
            FileSystemResource resource = new FileSystemResource(file);
            MultiValueMap<String, Object> param = new LinkedMultiValueMap<>();
            param.add("file", resource);

            ResponseResult responseResult = restTemplate.postForObject(txOssUploadUrl, param, ResponseResult.class);
            fileId = (String) responseResult.getData();
        } catch (Exception e) {
            fileId = null;
        }
        return fileId;
    }

说明: 处理数据的业务逻辑代码就不用贴了

6、上传文件到cos

    @RequestMapping("/txOssUpload")
    @ResponseBody
    public ResponseResult txOssUpload(@RequestParam("file") MultipartFile file) throws UnsupportedEncodingException {
        if (null == file || file.isEmpty()) {
            return ResponseResult.fail("文件不能为空");
        }

        String originalFilename = file.getOriginalFilename();
        originalFilename = MimeUtility.decodeText(originalFilename);// 解决中文乱码问题
        String contentType = getContentType(originalFilename);
        String key;

        InputStream ins = null;
        File f = null;

        try {
            ins = file.getInputStream();
            f = new File(originalFilename);
            inputStreamToFile(ins, f);
            key = iFileStorageClient.txOssUpload(new FileInputStream(f), originalFilename, contentType);
        } catch (Exception e) {
            return ResponseResult.fail(e.getMessage());
        } finally {
            if (null != ins) {
                try {
                    ins.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (f.exists()) {// 删除临时文件
                f.delete();
            }
        }

        return ResponseResult.ok(key);
    }

    public static void inputStreamToFile(InputStream ins,File file) {
        try {
            OutputStream os = new FileOutputStream(file);
            int bytesRead = 0;
            byte[] buffer = new byte[8192];
            while ((bytesRead = ins.read(buffer, 0, 8192)) != -1) {
                os.write(buffer, 0, bytesRead);
            }
            os.close();
            ins.close();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public String txOssUpload(FileInputStream inputStream, String key, String contentType) {
        key = Uuid.getUuid() + "-" + key;
        OSSUtil.txOssUpload(inputStream, key, contentType);
        try {
            if (null != inputStream) {
                inputStream.close();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return key;
    }

    public static void txOssUpload(FileInputStream inputStream, String key, String contentType) {
        ObjectMetadata objectMetadata = new ObjectMetadata();
        try{
            int length = inputStream.available();
            objectMetadata.setContentLength(length);
        }catch (Exception e){
            logger.info(e.getMessage());
        }
        objectMetadata.setContentType(contentType);
        cosclient.putObject(txbucketName, key, inputStream, objectMetadata);
    }

7、下载文件

    /**
     * 腾讯云文件下载
     * @param response
     * @param id
     * @return
     */
    @RequestMapping("/txOssDownload")
    public Object txOssDownload(HttpServletResponse response, String id) {
        COSObjectInputStream cosObjectInputStream = iFileStorageClient.txOssDownload(id, response);
        String contentType = getContentType(id);
        FileUtil.txOssDownload(response, contentType, cosObjectInputStream, id);
        return null;
    }

    public static void txOssDownload(HttpServletResponse response, String contentType, InputStream fileStream, String fileName) {
        FileOutputStream fos = null;
        response.reset();
        OutputStream os = null;
        try {
            response.setContentType(contentType + "; charset=utf-8");
            if(!contentType.equals(PlConstans.FileContentType.image)){
                try {
                    response.setHeader("Content-Disposition", "attachment; filename=" + new String(fileName.getBytes("UTF-8"), "ISO8859-1"));
                } catch (UnsupportedEncodingException e) {
                    response.setHeader("Content-Disposition", "attachment; filename=" + fileName);
                    logger.error("encoding file name failed", e);
                }
            }

            os = response.getOutputStream();

            byte[] b = new byte[1024 * 1024];
            int len;
            while ((len = fileStream.read(b)) > 0) {
                os.write(b, 0, len);
                os.flush();
                try {
                    if(fos != null) {
                        fos.write(b, 0, len);
                        fos.flush();
                    }
                } catch (Exception e) {
                    logger.error(e.getMessage());
                }
            }
        } catch (IOException e) {
            IOUtils.closeQuietly(fos);
            fos = null;
        } finally {
            IOUtils.closeQuietly(os);
            IOUtils.closeQuietly(fileStream);
            if(fos != null) {
                IOUtils.closeQuietly(fos);
            }
        }
    }

8、读取网络文件流

    /**
     * 读取网络文件流
     * @param url
     * @return
     */
    public static InputStream readFileFromURL(String url) {
        if (StringUtils.isBlank(url)) {
            return null;
        }

        HttpClient httpClient = new DefaultHttpClient();
        HttpGet methodGet = new HttpGet(url);
        try {
            HttpResponse response = httpClient.execute(methodGet);
            if (response.getStatusLine().getStatusCode() == 200) {
                HttpEntity entity = response.getEntity();
                return entity.getContent();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

9、ExcelUtil

    /**
     * 读excel
     * @param inputStream 文件输入流
     * @return list集合
     */
    public static List<Object> read(InputStream inputStream) {
        return EasyExcelFactory.read(inputStream, new Sheet(1, 1));
    }

    /**
     * 写excel
     * @param data list数据
     * @param clazz
     * @param saveFilePath 文件保存路径
     * @throws IOException
     */
    public static void write(List<? extends BaseRowModel> data, Class<? extends BaseRowModel> clazz, String saveFilePath) throws IOException {
        File tempFile = new File(saveFilePath);
        OutputStream out = new FileOutputStream(tempFile);
        ExcelWriter writer = EasyExcelFactory.getWriter(out);
        Sheet sheet = new Sheet(1, 3, clazz, "Sheet1", null);
        writer.write(data, sheet);
        writer.finish();
        out.close();
    }

说明: 至此, 整个流程算是完整了, 下面将其他知识点代码也贴出来参考

七、其他

1、@LoginRequired注解

/**
 * 在需要登录验证的Controller的方法上使用此注解
 */
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface LoginRequired {
}

2、MyControllerAdvice

@ControllerAdvice
public class MyControllerAdvice {

    @ResponseBody
    @ExceptionHandler(TokenValidationException.class)
    public JsonResponse tokenValidationExceptionHandler() {
        return JsonResponse.loginInvalid();
    }

    @ResponseBody
    @ExceptionHandler(ServiceException.class)
    public JsonResponse serviceExceptionHandler(ServiceException se) {
        return JsonResponse.fail(se.getMsg());
    }

    @ResponseBody
    @ExceptionHandler(Exception.class)
    public JsonResponse exceptionHandler(Exception e) {
        e.printStackTrace();
        return JsonResponse.fail(e.getMessage());
    }

}

3、AuthenticationInterceptor

public class AuthenticationInterceptor implements HandlerInterceptor {

    private static final String CURRENT_USER = "user";

    @Autowired
    private UserService userService;

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {
        // 如果不是映射到方法直接通过
        if (!(handler instanceof HandlerMethod)) {
            return true;
        }
        HandlerMethod handlerMethod = (HandlerMethod) handler;
        Method method = handlerMethod.getMethod();

        // 判断接口是否有@LoginRequired注解, 有则需要登录
        LoginRequired methodAnnotation = method.getAnnotation(LoginRequired.class);
        if (methodAnnotation != null) {
            // 验证token
            Integer userId = JwtUtil.verifyToken(request);
            PLUser plUser = userService.selectByPrimaryKey(userId);
            if (null == plUser) {
                throw new RuntimeException("用户不存在，请重新登录");
            }
            request.setAttribute(CURRENT_USER, plUser);
            return true;
        }
        return true;
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {
    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
    }
}

4、JwtUtil

    public static final long EXPIRATION_TIME = 2592_000_000L; // 有效期30天
    public static final String SECRET = "pl_token_secret";
    public static final String HEADER = "token";
    public static final String USER_ID = "userId";

    /**
     * 根据userId生成token
     * @param userId
     * @return
     */
    public static String generateToken(String userId) {
        HashMap<String, Object> map = new HashMap<>();
        map.put(USER_ID, userId);
        String jwt = Jwts.builder()
                .setClaims(map)
                .setExpiration(new Date(System.currentTimeMillis() + EXPIRATION_TIME))
                .signWith(SignatureAlgorithm.HS512, SECRET)
                .compact();
        return jwt;
    }

    /**
     * 验证token
     * @param request
     * @return 验证通过返回userId
     */
    public static Integer verifyToken(HttpServletRequest request) {
        String token = request.getHeader(HEADER);
        if (token != null) {
            try {
                Map<String, Object> body = Jwts.parser()
                        .setSigningKey(SECRET)
                        .parseClaimsJws(token)
                        .getBody();

                for (Map.Entry entry : body.entrySet()) {
                    Object key = entry.getKey();
                    Object value = entry.getValue();
                    if (key.toString().equals(USER_ID)) {
                        return Integer.valueOf(value.toString());// userId
                    }
                }
                return null;
            } catch (Exception e) {
                logger.error(e.getMessage());
                throw new TokenValidationException("unauthorized");
            }
        } else {
            throw new TokenValidationException("missing token");
        }
    }