快捷導(dǎo)航

JAVA 創(chuàng)建線程池的注意事項(xiàng)

更新時(shí)間：2020年07月17日 09:15:36 作者：_Phoenix

這篇文章主要介紹了JAVA 創(chuàng)建線程池的注意事項(xiàng)，文中講解非常細(xì)致，代碼幫助大家更好的理解和學(xué)習(xí)，感興趣的朋友可以了解下

1、創(chuàng)建線程或線程池時(shí)請(qǐng)指定有意義的線程名稱，方便出錯(cuò)時(shí)回溯。創(chuàng)建線程池的時(shí)候請(qǐng)使用帶ThreadFactory的構(gòu)造函數(shù)，并且提供自定義ThreadFactory實(shí)現(xiàn)或者使用第三方實(shí)現(xiàn)。

ThreadFactory namedThreadFactory = new ThreadFactoryBuilder()
.setNameFormat("demo-pool-%d").build();
ExecutorService singleThreadPool = new ThreadPoolExecutor(1, 1,
0L, TimeUnit.MILLISECONDS,
new LinkedBlockingQueue<Runnable>(1024), namedThreadFactory, new ThreadPoolExecutor.AbortPolicy());

singleThreadPool.execute(()-> System.out.println(Thread.currentThread().getName()));
singleThreadPool.shutdown();


public class TimerTaskThread extends Thread {
public TimerTaskThread(){
super.setName("TimerTaskThread"); …
}

2、線程池不允許使用Executors去創(chuàng)建，而是通過ThreadPoolExecutor的方式，這樣的處理方式讓寫的同學(xué)更加明確線程池的運(yùn)行規(guī)則，規(guī)避資源耗盡的風(fēng)險(xiǎn)。

說明：Executors返回的線程池對(duì)象的弊端如下：

1）FixedThreadPool和SingleThreadPool:
允許的請(qǐng)求隊(duì)列長(zhǎng)度為Integer.MAX_VALUE，可能會(huì)堆積大量的請(qǐng)求，從而導(dǎo)致OOM。

2）CachedThreadPool:
允許的創(chuàng)建線程數(shù)量為Integer.MAX_VALUE，可能會(huì)創(chuàng)建大量的線程，從而導(dǎo)致OOM。

Positive example 1：

//org.apache.commons.lang3.concurrent.BasicThreadFactory
ScheduledExecutorService executorService = new ScheduledThreadPoolExecutor(1,
new BasicThreadFactory.Builder().namingPattern("example-schedule-pool-%d").daemon(true).build());

Positive example 2：

ThreadFactory namedThreadFactory = new ThreadFactoryBuilder()
.setNameFormat("demo-pool-%d").build();

//Common Thread Pool
ExecutorService pool = new ThreadPoolExecutor(5, 200,
0L, TimeUnit.MILLISECONDS,
new LinkedBlockingQueue<Runnable>(1024), namedThreadFactory, new ThreadPoolExecutor.AbortPolicy());

pool.execute(()-> System.out.println(Thread.currentThread().getName()));
pool.shutdown();//gracefully shutdown

Positive example 3：

<bean id="userThreadPool"
class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
<property name="corePoolSize" value="10" />
<property name="maxPoolSize" value="100" />
<property name="queueCapacity" value="2000" />

<property name="threadFactory" value= threadFactory />
<property name="rejectedExecutionHandler">
<ref local="rejectedExecutionHandler" />
</property>
</bean>
//in code
userThreadPool.execute(thread);

3、線程資源必須通過線程池提供，不允許在應(yīng)用中自行顯式創(chuàng)建線程。

說明：

使用線程池的好處是減少在創(chuàng)建和銷毀線程上所花的時(shí)間以及系統(tǒng)資源的開銷，解決資源不足的問題。

如果不使用線程池，有可能造成系統(tǒng)創(chuàng)建大量同類線程而導(dǎo)致消耗完內(nèi)存或者“過度切換”的問題。

ThreadFactory namedThreadFactory = new ThreadFactoryBuilder()
.setNameFormat("demo-pool-%d").build();
ExecutorService singleThreadPool = new ThreadPoolExecutor(1, 1,
0L, TimeUnit.MILLISECONDS,
new LinkedBlockingQueue<Runnable>(1024), namedThreadFactory, new ThreadPoolExecutor.AbortPolicy());

singleThreadPool.execute(()-> System.out.println(Thread.currentThread().getName()));
singleThreadPool.shutdown();

以上就是JAVA 創(chuàng)建線程池的注意事項(xiàng)的詳細(xì)內(nèi)容，更多關(guān)于JAVA 創(chuàng)建線程池注意事項(xiàng)的資料請(qǐng)關(guān)注腳本之家其它相關(guān)文章！

您可能感興趣的文章: