关于使用Future多线程处理多个任务并获取所有返回值，堵塞获取所有子线程的返回值。

柔光的暖阳◎ 2023-10-10 14:53 7阅读 0赞

创建一个线程池：

// 全局异步执行的线程池
        @Bean(name = "globalAsyncThreadPool")
        public ThreadPoolExecutor globalAsyncThreadPool() {
            return new ThreadPoolExecutor(10, 100, 60, TimeUnit.SECONDS,
                    new ArrayBlockingQueue<>(10000), Executors.defaultThreadFactory(),
                    new ThreadPoolExecutor.CallerRunsPolicy());
        }

可写在启动类中，在各层的调用；

@Resource(name = "globalAsyncThreadPool")
        private ThreadPoolExecutor globalAsyncThreadPool;

之后便是执行子线程：

Future<AjaxResult> t1= globalAsyncThreadPool.submit(() -> {
                //业务代码，必须有返回值 
                return AjaxResult.success('返回值');
            });

示例，可写多个：

Future<AjaxResult> t1= globalAsyncThreadPool.submit(() -> {
                Map<String, ICFaInvestigationNorm> normMap = null;
                try {
                    normMap = varianceAnalysisService.getInvestigationData(investigationId, normAppendMap);
                } catch (Exception e) {
                    return AjaxResult.error(e.getMessage());
                }
                return AjaxResult.success(normMap);
            });

再就是获取执行结果，可用一个try包起来，再try外定义接收返回值的变量，在内部通过get（）方法获取结果后，赋值给返回值变量即可：

Map<String, ICFaInvestigationNorm> normMap = null;
            List<ICBmLevel> targetLevels = null;
            List<ICBmLevel> allLevels = null;
            Map<String, Double> levelDetailMap = null;
            List<ICBmEvaluationTitleDTO> icBmEvaluationTitleList = null;
            try {
                AjaxResult investigationResult = investigationFuture.get();
                if((Integer)investigationResult.get(AjaxResult.CODE_TAG) != HttpStatus.SUCCESS) {
                    return investigationResult;
                }
                AjaxResult targetLevelsResult = targetLevelsFuture.get();
                if((Integer)targetLevelsResult.get(AjaxResult.CODE_TAG) != HttpStatus.SUCCESS) {
                    return targetLevelsResult;
                }
                AjaxResult allLevelsResult = allLevelsFuture.get();
                if((Integer)allLevelsResult.get(AjaxResult.CODE_TAG) != HttpStatus.SUCCESS) {
                    return allLevelsResult;
                }
                AjaxResult levelDetailResult = levelDetailFuture.get();
                if((Integer)levelDetailResult.get(AjaxResult.CODE_TAG) != HttpStatus.SUCCESS) {
                    return levelDetailResult;
                }
                AjaxResult evaluationTitleResult = evaluationTitleFuture.get();
                if((Integer)evaluationTitleResult.get(AjaxResult.CODE_TAG) != HttpStatus.SUCCESS) {
                    return evaluationTitleResult;
                }
                normMap = (Map<String, ICFaInvestigationNorm>)investigationResult.get(AjaxResult.DATA_TAG);
                targetLevels = (List<ICBmLevel>)targetLevelsResult.get(AjaxResult.DATA_TAG);
                allLevels = (List<ICBmLevel>)allLevelsResult.get(AjaxResult.DATA_TAG);
                levelDetailMap = (Map<String, Double>)levelDetailResult.get(AjaxResult.DATA_TAG);
                icBmEvaluationTitleList = (List<ICBmEvaluationTitleDTO>)evaluationTitleResult.get(AjaxResult.DATA_TAG);
            } catch (InterruptedException e) {
                e.printStackTrace();
                return AjaxResult.error("线程中断");
            } catch (ExecutionException e) {
                e.printStackTrace();
                return AjaxResult.error("线程执行异常");
            }

更新，22.9.14

可将子线程返回值的报错不用return，而使用抛出

Integer targetLevelCode = null;
            List<ICBmLevel> allLevels = null;
            Integer firstNormValue = 0;
            try {
                AjaxResult targetLevelCodeResult = targetLevelCodeFuture.get();
                if((Integer)targetLevelCodeResult.get(AjaxResult.CODE_TAG) != HttpStatus.SUCCESS) {
                    throw new Exception(String.valueOf(targetLevelCodeResult.get(AjaxResult.MSG_TAG)));
                }
                AjaxResult allLevelsResult = allLevelsFuture.get();
                if((Integer)allLevelsResult.get(AjaxResult.CODE_TAG) != HttpStatus.SUCCESS) {
                    throw new Exception(String.valueOf(allLevelsResult.get(AjaxResult.MSG_TAG)));
                }
                AjaxResult firstNormResult = firstNormFuture.get();
                if((Integer)firstNormResult.get(AjaxResult.CODE_TAG) !=HttpStatus.SUCCESS) {
                    throw new Exception(String.valueOf(firstNormResult.get(AjaxResult.MSG_TAG)));
                }
                targetLevelCode = (Integer)targetLevelCodeResult.get(AjaxResult.DATA_TAG);
                allLevels = (List<ICBmLevel>)allLevelsResult.get(AjaxResult.DATA_TAG);
                firstNormValue = (Integer)firstNormResult.get(AjaxResult.DATA_TAG);
            } catch (InterruptedException e) {
                e.printStackTrace();
                throw new Exception("线程中断");
            } catch (ExecutionException e) {
                e.printStackTrace();
                throw new Exception("线程执行异常");
            }