newFixedThreadPool线程池实现多线程
List<PackageAgreementEntity> entityList = new CopyOnWriteArrayList<>();//多线程 10个线程//int threadNum = 10;int listSize = 300;List<List<PackageAgreementDto>> splitData = Lists.partition(packageAgreementList, listSize);//CountDownLatch latch = new CountDownLatch(splitData.size());//声明线程池对象ExecutorService touchWorker = Executors.newFixedThreadPool(splitData.size());//不加这个会导致线程不安全,丢失数据Semaphore semaphore = new Semaphore(splitData.size());//定义几个许可List<PackageAgreementErroDto> errorList2 = new CopyOnWriteArrayList();for (int i = 0; i < packageAgreementList.size(); i++) {final int j = i;semaphore.acquire();touchWorker.execute(()->{try {logger.info(Thread.currentThread().getName()+ j);logger.info("数据第几条:" + j);//校验物料、供应商、ou、地点信息是否存在packageAgreementService.checkMultiData(packageAgreementList.get(j), j ,user, dateFormat, errorList2, entityList);semaphore.release();} catch (ParseException e) {e.printStackTrace();}});}//每隔10s检测线程是否执行结束boolean flag = touchWorker.awaitTermination(10, TimeUnit.SECONDS);if(!flag){logger.info("一揽子协议价格录入完成!");}
需要注意的问题点,多线程处理List数据可能发生线程不安全,
引入CopyOnWriteArrayList,Semaphore解决,或者加锁解决问题;所有线程执行完毕后再进行后续业务的处理,引入awaitTermination()方法。