加鎖阻塞，一個(gè)condition對(duì)應(yīng)一個(gè)線程，以便于喚醒時(shí)使用該condition一定會(huì)喚醒該線程

/** * 獲取探測(cè)點(diǎn)數(shù)據(jù),長輪詢實(shí)現(xiàn) * @param messageId * @return */ public JSONObject getToutData(String messageId) {Message message = toutMessageCache.get(messageId);if (message == null) { // 等待 lock.lock(); try {Condition condition = lock.newCondition();conditionMap.put(messageId + '_data', condition);condition.await(CONNECTION_HOLD_TIMEOUT, TimeUnit.SECONDS); // 等待60s } catch (InterruptedException e) {// 等待超時(shí)， do nothing } finally {lock.unlock(); }}// 再次嘗試獲取message = toutMessageCache.get(messageId);if (message == null) { // 如果還沒有， 返回空對(duì)象 return null;}byte[] bytes = message.getDataBytes();if (bytes == null) { return null;}String resStr = new String(bytes, StandardCharsets.UTF_8);//log.info('resStr: {}', resStr);JSONObject resObj;try { resObj = new JSONObject(resStr); resObj.put('invokeTime', DateUtil.format(new Date(resObj.getLong('invokeTime')), DatePattern.NORM_DATETIME_MS_PATTERN));} catch (Exception e) { resObj = new JSONObject();}return resObj; }2. 回調(diào)

當(dāng)異步數(shù)據(jù)返回，使用上一步的condition喚醒線程

public void callback(Message message) { String messageId = message.getId(); toutMessageCache.put(message.getId(), message); String messageDataId = messageId + '_data'; if (conditionMap.containsKey(messageDataId)) {lock.lock();try { Condition condition = conditionMap.get(messageDataId); condition.signal();} catch (Exception e) { e.printStackTrace();} finally { lock.unlock(); conditionMap.remove(messageDataId);} }}3. 喚醒

執(zhí)行回調(diào)操作

public void distribute(Message message, ChannelHandlerContext ctx) { MessageType messageType = message.getMessageType(); switch (messageType) { case TOUT_DATA_RESPONSE: // 數(shù)據(jù)響應(yīng) toutService.callback(message); break; }}4. 調(diào)用

調(diào)用時(shí)，判斷返回的值是否為空，如果為空，與前端約定，當(dāng)返回該狀態(tài)值時(shí)，應(yīng)再次發(fā)起相同請(qǐng)求

/*** 獲取探測(cè)數(shù)據(jù)(使用長輪詢實(shí)現(xiàn))* @param linkId* @return*/@GetMapping('/data')public ResultVO getToutData(String linkId) { JSONObject resObj = toutService.getToutData(linkId); if (resObj == null || resObj.isEmpty()) { return ResultVOUtil.error(ResultEnum.NO_MESSAGE_HOLD_CONNECTION); } return ResultVOUtil.success(resObj);}5.前端實(shí)現(xiàn)

簡單使用遞歸實(shí)現(xiàn)了當(dāng)數(shù)據(jù)返回?zé)o效時(shí)再次發(fā)起請(qǐng)求

let that = thisfunction getData() { if (toutStatus === statusEnum.start) { getToutData({ linkId }).then(res => { if (res.code === ERROR_CODE_OK) { that.toutData = res.data toutStatus = statusEnum.resData that._btnStatus() } else { getData() } }) } } // 遞歸循環(huán)調(diào)用 getData()

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