java线程学习

//线程池创建，使用线程池提交任务，线程使用Callable接口，线程执行有返回值，等待所有子线程执行完成再继续执行主线程

　　public static void main(String[] args) {
        int corePoolSize = 3;
        int maximumPoolSize = Runtime.getRuntime().availableProcessors() * 2;
        BlockingQueue<Runnable> queue = new ArrayBlockingQueue<>(512);
        RejectedExecutionHandler policy = new ThreadPoolExecutor.DiscardPolicy(); //什么也不做，直接忽略
        ExecutorService threadPoolExecutor = new ThreadPoolExecutor(corePoolSize, maximumPoolSize, 0, TimeUnit.SECONDS, queue, policy);
        submitTisks(gatherDate, hbaseConfig, corePoolSize, threadPoolExecutor);
    }
    
    /**
     * 提交任务
     * @param gatherDate
     * @param hbaseConfig
     * @param corePoolSize
     * @param threadPoolExecutor
     */
    private static void submitTisks(String gatherDate, Configuration hbaseConfig, int corePoolSize, ExecutorService threadPoolExecutor) {
        List<Future<Boolean>> taskFutureList = new ArrayList<>();
        // 提交任务，任务的执行由线程池去调用执行并管理。
        Future<Boolean> gpsfuture = threadPoolExecutor.submit(new GPSTask(hbaseConfig, gatherDate, xikangTidList, rootPath));
        // 这里获取结果任务的Future，并放到list中，供所有任务提交完后，通过每个任务的Future判断执行状态和结果。
        taskFutureList.add(gpsfuture);
        int done = 0; //完成任务的数量
        while (!taskFutureList.isEmpty()) {
            Iterator<Future<Boolean>> iter = taskFutureList.iterator();
            while (iter.hasNext()) {
                Future<Boolean> fut = iter.next();
                if (fut.isDone()) {
                    try{
                        Boolean flag = fut.get();
                        if (flag){  done++;}
                    }catch (Exception e){
                        e.printStackTrace();
                    }
                    iter.remove();
                }
            }
        }
    }

    /************************************使用Callable接口**************************************/
    static class GPSTask implements Callable<Boolean> {
        Configuration config;
        String recordDate;
        List<Long> xkDatanoList;
        String rootPath;
        Thread currentThread;
        public GPSTask(Configuration config, String recordDate, List<Long> xkDatanoList,String rootPath) {
            this.config = config;
            this.recordDate = recordDate;
            this.xkDatanoList = xkDatanoList;
            this.rootPath = rootPath;
        }
        @Override
        public Boolean call() throws Exception {
            this.currentThread = Thread.currentThread();
            return FindDataUtil.getData4HbaseGPSSQ(config, recordDate, xkDatanoList,rootPath,currentThread);
        }
    }

//线程创建，主线程等待子线执行完成后再执行（针对子线程只有1个的时候），子线程使用Thread

　　public static void main(String[] args) {
        GPSRunTask gpsRunTask1 = new GPSRunTask(hbaseConfig, gatherDate, xikangTidList, rootPath,gpsPath);
        GPSRunTask gpsRunTask2 = new GPSRunTask(hbaseConfig, gatherDate, xikangTidList, rootPath,gpsPath);
        gpsRunTask1.start () ;
        gpsRunTask2.start () ;
        try {
            gpsRunTask1.join();
            gpsRunTask2.join();
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        // 等待已提交的任务全部结束 不再接受新的任务
        System.out.println("主线程再次执行");
    }

    static class GPSRunTask extends Thread  {
        Configuration config;
        String recordDate;
        List<Long> xkDatanoList;
        String rootPath;
        String gpsPath;
        Thread currentThread;
        public GPSRunTask(Configuration config, String recordDate, List<Long> xkDatanoList, String rootPath, String gpsPath) {
            this.config = config;
            this.recordDate = recordDate;
            this.xkDatanoList = xkDatanoList;
            this.rootPath = rootPath;
            this.gpsPath = gpsPath;
        }
        public void run(){
            this.currentThread = Thread.currentThread();
            synchronized (currentThread) {
                System.out.println("线程："+currentThread.getName());
                try {
                    Thread.sleep(10000L);
                    System.out.println(recordDate);
                }catch (InterruptedException e){
                    e.printStackTrace();
                }
            }
        }

//使用倒数计数器收集所有线程执行结果的状态，（此种方法也适用于使用 ExecutorService summit 的任务的执行）