多线程代码

拼搏现实的明天。 2022-02-28 06:16 210阅读 0赞

# **更多请访问 [www.itkc8.com][]** #

public String list2Str(List<String> list, final int nThreads) throws Exception {
            if (CollectionUtils.isEmpty(list)) {
                return null;
            }
            int size = list.size();
            System.out.println("处理key的大小："+list.size());
            ExecutorService executorService = Executors.newFixedThreadPool(nThreads);
            List<Future<List<GpsUploadVO>>> futures = new ArrayList<>(nThreads);
            for (int i = 0; i < nThreads; i++) {
                final List<String> subList = list.subList(size / nThreads * i, size / nThreads * (i + 1));
                Callable<List<GpsUploadVO>> task = () -> {
                    List<GpsUploadVO> gpss = new ArrayList<>();
                    for (String str : subList) {
                        List<GpsUploadVO> range = redisTemplate.opsForList().range(str, 0, 4);
                        gpss.addAll(range);
                    }
                    return gpss;
                };
                futures.add(executorService.submit(task));
            }
            List<GpsUploadVO> lt = new ArrayList<>();
            for (Future<List<GpsUploadVO>> future : futures) {
                List<GpsUploadVO> ls = future.get();
                lt.addAll(ls);
            }
            executorService.shutdown();
            System.out.println("list的大小:"+lt.size());
            Map<String, List<GpsUploadVO>> groupBy = lt.stream().collect(Collectors.groupingBy(GpsUploadVO::getPhoneNum));
            System.out.println("分组大小:"+groupBy.size());
            return null;
        }

public String list2Str(List<String> list, final int nThreads) throws Exception {  
                if (list == null || list.isEmpty()) {  
                    return null;  
                }  
                  
                StringBuffer ret = new StringBuffer();  
          
                int size = list.size();  
                ExecutorService executorService = Executors.newFixedThreadPool(nThreads);  
                List<Future<String>> futures = new ArrayList<Future<String>>(nThreads);  
                  
                for (int i = 0; i < nThreads; i++) {  
                    final List<String> subList = list.subList(size / nThreads * i, size / nThreads * (i + 1));  
                    Callable<String> task = new Callable<String>() {  
                        @Override  
                        public String call() throws Exception {  
                            StringBuffer sb = new StringBuffer();  
                            for (String str : subList) {  
                                sb.append(str);  
                            }  
                            return sb.toString();  
                        }  
                    };  
                    futures.add(executorService.submit(task));  
                }  
                  
                for (Future<String> future : futures) {  
                    ret.append(future.get());  
                }  
                executorService.shutdown();  
                  
                return ret.toString();  
            }  
        }

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