@Test
public void testException() throws InterruptedException {
    // 創(chuàng)建1個(gè)線程的調(diào)度任務(wù)線程池
    ScheduledExecutorService scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
    // 創(chuàng)建一個(gè)任務(wù)
    Runnable runnable = new Runnable() {
        volatile int num = 0;
        @Override
        public void run() {
            num ++;
            // 模擬執(zhí)行報(bào)錯(cuò)
            if(num > 5) {
                throw new RuntimeException("執(zhí)行錯(cuò)誤");
            }
            log.info("exec num: [{}].....", num);
        }
    };
    // 每隔1秒鐘執(zhí)行一次任務(wù)
    scheduledExecutorService.scheduleAtFixedRate(runnable, 0, 1, TimeUnit.SECONDS);
    Thread.sleep(10000);
}

@Slf4j
public class RunnableWrapper implements Runnable {
    // 實(shí)際要執(zhí)行的線程任務(wù)
    private Runnable task;
    // 線程任務(wù)被創(chuàng)建出來(lái)的時(shí)間
    private long createTime;
    // 線程任務(wù)被線程池運(yùn)行的開(kāi)始時(shí)間
    private long startTime;
    // 線程任務(wù)被線程池運(yùn)行的結(jié)束時(shí)間
    private long endTime;
    // 線程信息
    private String taskInfo;
    private boolean showWaitLog;
    /**
     * 執(zhí)行間隔時(shí)間多久，打印日志
     */
    private long durMs = 1000L;
    // 當(dāng)這個(gè)任務(wù)被創(chuàng)建出來(lái)的時(shí)候，就會(huì)設(shè)置他的創(chuàng)建時(shí)間
    // 但是接下來(lái)有可能這個(gè)任務(wù)提交到線程池后，會(huì)進(jìn)入線程池的隊(duì)列排隊(duì)
    public RunnableWrapper(Runnable task, String taskInfo) {
        this.task = task;
        this.taskInfo = taskInfo;
        this.createTime = System.currentTimeMillis();
    }
    public void setShowWaitLog(boolean showWaitLog) {
        this.showWaitLog = showWaitLog;
    }
    public void setDurMs(long durMs) {
        this.durMs = durMs;
    }
    // 當(dāng)任務(wù)在線程池排隊(duì)的時(shí)候，這個(gè)run方法是不會(huì)被運(yùn)行的
    // 但是當(dāng)任務(wù)結(jié)束了排隊(duì)，得到線程池運(yùn)行機(jī)會(huì)的時(shí)候，這個(gè)方法會(huì)被調(diào)用
    // 此時(shí)就可以設(shè)置線程任務(wù)的開(kāi)始運(yùn)行時(shí)間
    @Override
    public void run() {
        this.startTime = System.currentTimeMillis();
        // 此處可以通過(guò)調(diào)用監(jiān)控系統(tǒng)的API，實(shí)現(xiàn)監(jiān)控指標(biāo)上報(bào)
        // 用線程任務(wù)的startTime-createTime，其實(shí)就是任務(wù)排隊(duì)時(shí)間
        // 這邊打印日志輸出，也可以輸出到監(jiān)控系統(tǒng)中
        if(showWaitLog) {
            log.info("任務(wù)信息: [{}], 任務(wù)排隊(duì)時(shí)間: [{}]ms", taskInfo, startTime - createTime);
        }
        // 接著可以調(diào)用包裝的實(shí)際任務(wù)的run方法
        try {
            task.run();
        } catch (Exception e) {
            log.error("run task error", e);
            throw e;
        }
        // 任務(wù)運(yùn)行完畢以后，會(huì)設(shè)置任務(wù)運(yùn)行結(jié)束的時(shí)間
        this.endTime = System.currentTimeMillis();
        // 此處可以通過(guò)調(diào)用監(jiān)控系統(tǒng)的API，實(shí)現(xiàn)監(jiān)控指標(biāo)上報(bào)
        // 用線程任務(wù)的endTime - startTime，其實(shí)就是任務(wù)運(yùn)行時(shí)間
        // 這邊打印任務(wù)執(zhí)行時(shí)間，也可以輸出到監(jiān)控系統(tǒng)中
        if(endTime - startTime > durMs) {
            log.info("任務(wù)信息: [{}], 任務(wù)執(zhí)行時(shí)間: [{}]ms", taskInfo, endTime - startTime);
        }
    }
}

// ScheduledThreadPoolExecutor#scheduleAtFixedRate
public ScheduledFuture<?> scheduleAtFixedRate(Runnable command,
                                              long initialDelay,
                                              long period,
                                              TimeUnit unit) {
    if (command == null || unit == null)
        throw new NullPointerException();
    if (period <= 0)
        throw new IllegalArgumentException();
    // 將執(zhí)行任務(wù)和參數(shù)包裝成ScheduledFutureTask對(duì)象
    ScheduledFutureTask<Void> sft =
        new ScheduledFutureTask<Void>(command,
                                      null,
                                      triggerTime(initialDelay, unit),
                                      unit.toNanos(period));
    RunnableScheduledFuture<Void> t = decorateTask(command, sft);
    sft.outerTask = t;
    // 延遲執(zhí)行
    delayedExecute(t);
    return t;
}
復(fù)制代碼

// ScheduledThreadPoolExecutor#delayedExecute
private void delayedExecute(RunnableScheduledFuture<?> task) {
        if (isShutdown())
            reject(task);
        else {
            // 將任務(wù)丟到阻塞隊(duì)列中
            super.getQueue().add(task);
            if (isShutdown() &&
                !canRunInCurrentRunState(task.isPeriodic()) &&
                remove(task))
                task.cancel(false);
            else
                // 開(kāi)啟工作線程，去執(zhí)行任務(wù)，或者從隊(duì)列中獲取任務(wù)執(zhí)行
                ensurePrestart();
        }
    }

// ScheduledFutureTask#run方法
public void run() {
    // 是不是周期性任務(wù)
    boolean periodic = isPeriodic();
    if (!canRunInCurrentRunState(periodic))
        cancel(false);
    // 不是周期性任務(wù)的話， 直接調(diào)用一次下面的run    
    else if (!periodic)
        ScheduledFutureTask.super.run();
    // 如果是周期性任務(wù)，則調(diào)用runAndReset方法，如果返回true，繼續(xù)執(zhí)行
    else if (ScheduledFutureTask.super.runAndReset()) {
        // 設(shè)置下次調(diào)度時(shí)間
        setNextRunTime();
        // 重新執(zhí)行調(diào)度任務(wù)
        reExecutePeriodic(outerTask);
    }
}

// FutureTask#runAndReset
protected boolean runAndReset() {
    if (state != NEW ||
        !UNSAFE.compareAndSwapObject(this, runnerOffset,
                                     null, Thread.currentThread()))
        return false;
    // 是否繼續(xù)下次調(diào)度，默認(rèn)false
    boolean ran = false;
    int s = state;
    try {
        Callable<V> c = callable;
        if (c != null && s == NEW) {
            try {
                // 執(zhí)行任務(wù)
                c.call(); 
                // 執(zhí)行成功的話，設(shè)置為true
                ran = true;
                // 異常處理，關(guān)鍵點(diǎn)
            } catch (Throwable ex) {
                // 不會(huì)修改ran的值，最終是false，同時(shí)也不打印異常堆棧
                setException(ex);
            }
        }
    } finally {
        // runner must be non-null until state is settled to
        // prevent concurrent calls to run()
        runner = null;
        // state must be re-read after nulling runner to prevent
        // leaked interrupts
        s = state;
        if (s >= INTERRUPTING)
            handlePossibleCancellationInterrupt(s);
    }
    // 返回結(jié)果
    return ran && s == NEW;
}