/*** redis工具类*/
@Component
public class RedisService {@Autowiredprivate RedisTemplate redisTemplate;/*** 写入缓存* @param key* @param value* @return*/public boolean set(finalString key, Object value) {boolean result = false;try {ValueOperations<Serializable, Object> operations = redisTemplate.opsForValue();operations.set(key, value);result = true;} catch (Exception e) {e.printStackTrace();}return result;}/*** 写入缓存设置时效时间* @param key* @param value* @return*/public boolean setEx(finalString key, Object value, Long expireTime) {boolean result = false;try {ValueOperations<Serializable, Object> operations = redisTemplate.opsForValue();operations.set(key, value);redisTemplate.expire(key, expireTime, TimeUnit.SECONDS);result = true;} catch (Exception e) {e.printStackTrace();}return result;}/*** 判断缓存中是否有对应的value* @param key* @return*/public boolean exists(finalString key) {return redisTemplate.hasKey(key);}/*** 读取缓存* @param key* @return*/public Objectget(finalString key) {Object result = null;ValueOperations<Serializable, Object> operations = redisTemplate.opsForValue();result = operations.get(key);return result;}/*** 删除对应的value* @param key*/public boolean remove(finalString key) {if (exists(key)) {Boolean delete = redisTemplate.delete(key);return delete;}returnfalse;}}

@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
public @interface AutoIdempotent {}

publicinterface TokenService {/*** 创建token* @return*/public  String createToken();/*** 检验token* @param request* @return*/public boolean checkToken(HttpServletRequest request) throws Exception;}

@Service
publicclass TokenServiceImpl implements TokenService {@Autowiredprivate RedisService redisService;/*** 创建token** @return*/@Overridepublic String createToken() {String str = RandomUtil.randomUUID();StrBuilder token = new StrBuilder();try {token.append(Constant.Redis.TOKEN_PREFIX).append(str);redisService.setEx(token.toString(), token.toString(),10000L);boolean notEmpty = StrUtil.isNotEmpty(token.toString());if (notEmpty) {return token.toString();}}catch (Exception ex){ex.printStackTrace();}returnnull;}/*** 检验token** @param request* @return*/@Overridepublic boolean checkToken(HttpServletRequest request) throws Exception {String token = request.getHeader(Constant.TOKEN_NAME);if (StrUtil.isBlank(token)) {// header中不存在tokentoken = request.getParameter(Constant.TOKEN_NAME);if (StrUtil.isBlank(token)) {// parameter中也不存在tokenthrownew ServiceException(Constant.ResponseCode.ILLEGAL_ARGUMENT, 100);}}if (!redisService.exists(token)) {thrownew ServiceException(Constant.ResponseCode.REPETITIVE_OPERATION, 200);}boolean remove = redisService.remove(token);if (!remove) {thrownew ServiceException(Constant.ResponseCode.REPETITIVE_OPERATION, 200);}returntrue;}
}

@Configuration
publicclass WebConfiguration extends WebMvcConfigurerAdapter {@Resourceprivate AutoIdempotentInterceptor autoIdempotentInterceptor;/*** 添加拦截器* @param registry*/@Overridepublic void addInterceptors(InterceptorRegistry registry) {registry.addInterceptor(autoIdempotentInterceptor);super.addInterceptors(registry);}
}

/*** 拦截器*/
@Component
publicclass AutoIdempotentInterceptor implements HandlerInterceptor {@Autowiredprivate TokenService tokenService;/*** 预处理** @param request* @param response* @param handler* @return* @throws Exception*/@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {if (!(handler instanceof HandlerMethod)) {returntrue;}HandlerMethod handlerMethod = (HandlerMethod) handler;Method method = handlerMethod.getMethod();//被ApiIdempotment标记的扫描AutoIdempotent methodAnnotation = method.getAnnotation(AutoIdempotent.class);if (methodAnnotation != null) {try {return tokenService.checkToken(request);// 幂等性校验, 校验通过则放行, 校验失败则抛出异常, 并通过统一异常处理返回友好提示}catch (Exception ex){ResultVo failedResult = ResultVo.getFailedResult(101, ex.getMessage());writeReturnJson(response, JSONUtil.toJsonStr(failedResult));throw ex;}}//必须返回true,否则会被拦截一切请求returntrue;}@Overridepublic void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {}@Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {}/*** 返回的json值* @param response* @param json* @throws Exception*/private void writeReturnJson(HttpServletResponse response, String json) throws Exception{PrintWriter writer = null;response.setCharacterEncoding("UTF-8");response.setContentType("text/html; charset=utf-8");try {writer = response.getWriter();writer.print(json);} catch (IOException e) {} finally {if (writer != null)writer.close();}}}

@RestController
publicclass BusinessController {@Resourceprivate TokenService tokenService;@Resourceprivate TestService testService;@PostMapping("/get/token")public String  getToken(){String token = tokenService.createToken();if (StrUtil.isNotEmpty(token)) {ResultVo resultVo = new ResultVo();resultVo.setCode(Constant.code_success);resultVo.setMessage(Constant.SUCCESS);resultVo.setData(token);return JSONUtil.toJsonStr(resultVo);}return StrUtil.EMPTY;}@AutoIdempotent@PostMapping("/test/Idempotence")public String testIdempotence() {String businessResult = testService.testIdempotence();if (StrUtil.isNotEmpty(businessResult)) {ResultVo successResult = ResultVo.getSuccessResult(businessResult);return JSONUtil.toJsonStr(successResult);}return StrUtil.EMPTY;}
}