## 一、概述 比如輪詢大量的記錄，這種job，可能會一次輪詢耗時數個小時到數天，那么，對于業務來說，是無法接受的；這個時候，平臺支持通過引入派生多線程的并發解決方案； ## 二、解決方案 通過動態派生多線程來實現；平臺中，通過提供RayCaller和RayThread來實現（實際上，除了調度服務，所有需要動態多線程的場景，這兩個平臺提供的基礎設施類，都能提供幫助）； 下面通過一個例子來說明； ``` @Component public class MultiThreadJobSample extends RayPeriodScheduleJob { @Override public boolean enabled() { return true; } @Override public String jobDesc() { return "多線程驗證"; } @Override public long periodInSeconds() { return 1 * minute; } @Override public long initialDelayInSeconds() { return 1 * minute; } @Override public String allowedIps() { return all; } @Autowired private RunCaller runCaller; @Override public void doInRayPeriodJob(SysJobExecution sysjobexecution) { int totalSize=10000; int sizePerThread=1000; List<Long> idList = new ArrayList(); for (long i = 0; i < totalSize; i++) { idList.add(i); } // 將待輪詢的大列表,依據條目進行分組,每個分組規劃一個線程執行 List<List<Long>> threadSplitList = ListUtil.splitListByPerListSize(idList, sizePerThread); int threadNum = threadSplitList.size(); runCaller.call(logger, threadNum, threadSplitList, sysjobexecution); } @Component public static class RunCaller extends RayCaller { @Override public void createThreadToExecutionTask(Logger logger, int threadNum, ExecutorService executor, CountDownLatch currentMainThreadLatch) { // 依據分配好的線程輪詢對象,每個線程分配均勻的條目輪詢對象列表 for (int i = 0; i < threadNum; i++) { List<List<Long>> threadSplitList = getMainTranferdBusinessObject(0); List<Long> listPer = threadSplitList.get(i); Runnable task = new RunThread(logger, i+ 1, currentMainThreadLatch, appendToEndOfMainTranferdAsCallerTransferedBusinessObjects(listPer)); executor.execute(task); } } } public static class RunThread extends RayThread { public RunThread(Logger logger, int threadIndex, CountDownLatch callerCountDownLatch, Object[] callerTranferdBusinessObjects) { super(logger, threadIndex, callerCountDownLatch, callerTranferdBusinessObjects); } @Override public void doBusinessInThread(Object[] callerTranferdBusinessObjects) { logger.error("{}開始運行", Thread.currentThread().getName()); SysJobExecution sysjobexecution = getCallerTranferdBusinessObject(1); List<Long> threadSplitList = getCallerTranferdBusinessObject(2); StringBuilder errorMessage = getCallerTranferdBusinessObject(3); // 針對當前線程需要需要處理的輪詢對象,進行輪詢 for (int i = 0; i < threadSplitList.size(); i++) { try { //可能拋異常的代碼 } catch(Exception ex) { errorMessage.append(ExceptionUtil.getFullStackTraceAsString(e)); } logger.error("處理了第{}條", threadSplitList.get(i)); } } } } ``` >[danger] RunThread 中的doBusinessInThread，才是真正執行業務的地方；