命名ExecutorService的线程和线程池

时间:2011-05-24 16:33:46

标签: java threadpool runnable executorservice managedthreadfactory

假设我有一个使用Executor框架的应用程序

Executors.newSingleThreadExecutor().submit(new Runnable(){
    @Override
    public void run(){
        // do stuff
    }
}

当我在调试器中运行此应用程序时,将使用以下(默认)名称创建一个线程:Thread[pool-1-thread-1]。正如您所看到的,这并不是非常有用,据我所知,Executor框架不能提供一种简单的方法来命名创建的线程或线程池。

那么,如何为线程/线程池提供名称呢?例如,Thread[FooPool-FooThread]

20 个答案:

答案 0 :(得分:249)

番石榴几乎总是拥有你need的东西。

ThreadFactory namedThreadFactory = 
  new ThreadFactoryBuilder().setNameFormat("my-sad-thread-%d").build()

并将其传递给您的ExecutorService

答案 1 :(得分:103)

您可以向ThreadFactory提供newSingleThreadScheduledExecutor(ThreadFactory threadFactory)。工厂将负责创建线程,并且能够命名它们。

引用Javadoc

  

创建新主题

     

使用ThreadFactory创建新主题。如果没有另外指定,则使用Executors.defaultThreadFactory(),它创建的线程都在同一ThreadGroup并具有相同的NORM_PRIORITY优先级和非守护进程状态。通过提供不同的ThreadFactory,您可以更改线程的名称,线程组,优先级,守护程序状态等。如果ThreadFactory通过从newThread返回null而无法创建线程,执行者将继续,但可能无法执行任何任务

答案 2 :(得分:86)

您可以尝试提供自己的线程工厂,它将创建具有适当名称的线程。这是一个例子:

class YourThreadFactory implements ThreadFactory {
   public Thread newThread(Runnable r) {
     return new Thread(r, "Your name");
   }
 }

Executors.newSingleThreadExecutor(new YourThreadFactory()).submit(someRunnable);

答案 3 :(得分:48)

您还可以在执行线程时更改线程的名称:

Thread.currentThread().setName("FooName");

如果你使用相同的ThreadFactory来处理不同类型的任务,那么这可能是有意义的。

答案 4 :(得分:43)

来自apache commons-lang的BasicThreadFactory对于提供命名行为也很有用。您可以使用Builder根据需要命名线程,而不是编写匿名内部类。以下是javadocs中的示例:

 // Create a factory that produces daemon threads with a naming pattern and
 // a priority
 BasicThreadFactory factory = new BasicThreadFactory.Builder()
     .namingPattern("workerthread-%d")
     .daemon(true)
     .priority(Thread.MAX_PRIORITY)
     .build();
 // Create an executor service for single-threaded execution
 ExecutorService exec = Executors.newSingleThreadExecutor(factory);

答案 5 :(得分:19)

Oracle有一个open RFE。根据Oracle员工的评论,他们似乎不了解这个问题,也无法修复。这是JDK中支持简单易用的东西之一(没有破坏向后兼容性)所以RFE被误解是一种耻辱。

正如所指出的,你需要实现自己的ThreadFactory。如果您不想仅仅为了这个目的而引入Guava或Apache Commons,我在这里提供了一个ThreadFactory实现,您可以使用它。它与您从JDK获得的内容完全相似,除了能够将线程名称前缀设置为“池”之外的其他内容。

package org.demo.concurrency;

import java.util.concurrent.ThreadFactory;
import java.util.concurrent.atomic.AtomicInteger;

/**
 * ThreadFactory with the ability to set the thread name prefix. 
 * This class is exactly similar to 
 * {@link java.util.concurrent.Executors#defaultThreadFactory()}
 * from JDK8, except for the thread naming feature.
 *
 * <p>
 * The factory creates threads that have names on the form
 * <i>prefix-N-thread-M</i>, where <i>prefix</i>
 * is a string provided in the constructor, <i>N</i> is the sequence number of
 * this factory, and <i>M</i> is the sequence number of the thread created 
 * by this factory.
 */
public class ThreadFactoryWithNamePrefix implements ThreadFactory {

    // Note:  The source code for this class was based entirely on 
    // Executors.DefaultThreadFactory class from the JDK8 source.
    // The only change made is the ability to configure the thread
    // name prefix.


    private static final AtomicInteger poolNumber = new AtomicInteger(1);
    private final ThreadGroup group;
    private final AtomicInteger threadNumber = new AtomicInteger(1);
    private final String namePrefix;

    /**
     * Creates a new ThreadFactory where threads are created with a name prefix
     * of <code>prefix</code>.
     *
     * @param prefix Thread name prefix. Never use a value of "pool" as in that
     *      case you might as well have used
     *      {@link java.util.concurrent.Executors#defaultThreadFactory()}.
     */
    public ThreadFactoryWithNamePrefix(String prefix) {
        SecurityManager s = System.getSecurityManager();
        group = (s != null) ? s.getThreadGroup()
                : Thread.currentThread().getThreadGroup();
        namePrefix = prefix + "-"
                + poolNumber.getAndIncrement()
                + "-thread-";
    }


    @Override
    public Thread newThread(Runnable r) {
        Thread t = new Thread(group, r,
                namePrefix + threadNumber.getAndIncrement(),
                0);
        if (t.isDaemon()) {
            t.setDaemon(false);
        }
        if (t.getPriority() != Thread.NORM_PRIORITY) {
            t.setPriority(Thread.NORM_PRIORITY);
        }
        return t;
    }
}

当您想要使用它时,您只需利用所有Executors方法允许您提供自己的ThreadFactory这一事实。

    Executors.newSingleThreadExecutor();

将为ExecutorService提供一个名为pool-N-thread-M的线程,但使用

    Executors.newSingleThreadExecutor(new ThreadFactoryWithNamePrefix("primecalc"));

您将获得一个名为primecalc-N-thread-M的线程的ExecutorService。瞧!

答案 6 :(得分:14)

如果您使用的是Spring,则可以CustomizableThreadFactory为其设置线程名称前缀。

示例:

ExecutorService alphaExecutor =
    Executors.newFixedThreadPool(10, new CustomizableThreadFactory("alpha-"));

答案 7 :(得分:8)

private class TaskThreadFactory implements ThreadFactory
{

    @Override
    public Thread newThread(Runnable r) {
        Thread t = new Thread(r, "TASK_EXECUTION_THREAD");

        return t;
    }

}

将ThreadFactory传递给executorservice,你很高兴

答案 8 :(得分:6)

快速而肮脏的方法是在Thread.currentThread().setName(myName);方法中使用run()

答案 9 :(得分:6)

扩展ThreadFactory

<强> public interface ThreadFactory

  

按需创建新线程的对象。使用线程工厂可以消除对新线程的调用的硬连线,使应用程序能够使用特殊的线程子类,优先级等。

<强> Thread newThread(Runnable r)

  

构造一个新线程。实现还可以初始化优先级,名称,守护程序状态,ThreadGroup等。

示例代码:

import java.util.concurrent.*;
import java.util.concurrent.atomic.*;

import java.util.concurrent.ThreadPoolExecutor.DiscardPolicy;

class SimpleThreadFactory implements ThreadFactory {
   String name;
   AtomicInteger threadNo = new AtomicInteger(0);

   public SimpleThreadFactory (String name){
       this.name = name;
   }
   public Thread newThread(Runnable r) {
     String threadName = name+":"+threadNo.incrementAndGet();
     System.out.println("threadName:"+threadName);
     return new Thread(r,threadName );
   }
   public static void main(String args[]){
        SimpleThreadFactory factory = new SimpleThreadFactory("Factory Thread");
        ThreadPoolExecutor executor= new ThreadPoolExecutor(1,1,60,
                    TimeUnit.SECONDS,new ArrayBlockingQueue<Runnable>(1),new ThreadPoolExecutor.DiscardPolicy());


        final ExecutorService executorService = Executors.newFixedThreadPool(5,factory);

        for ( int i=0; i < 100; i++){
            executorService.submit(new Runnable(){
                 public void run(){
                    System.out.println("Thread Name in Runnable:"+Thread.currentThread().getName());
                 }
            });
        }
        executorService.shutdown();
    }
 }

输出:

java SimpleThreadFactory

thread no:1
thread no:2
Thread Name in Runnable:Factory Thread:1
Thread Name in Runnable:Factory Thread:2
thread no:3
thread no:4
Thread Name in Runnable:Factory Thread:3
Thread Name in Runnable:Factory Thread:4
thread no:5
Thread Name in Runnable:Factory Thread:5

....等

答案 10 :(得分:3)

$objPHPExcel->getActiveSheet()->setCellValueExplicit("$row17", $data->telephone,PHPExcel_Cell_DataType::TYPE_STRING);

答案 11 :(得分:3)

您可以编写自己的ThreadFactory实现,例如使用一些现有的实现(如defaultThreadFactory)并在最后更改名称。

实现ThreadFactory的示例:

class ThreadFactoryWithCustomName implements ThreadFactory {
    private final ThreadFactory threadFactory;
    private final String name;

    public ThreadFactoryWithCustomName(final ThreadFactory threadFactory, final String name) {
        this.threadFactory = threadFactory;
        this.name = name;
    }

    @Override
    public Thread newThread(final Runnable r) {
        final Thread thread = threadFactory.newThread(r);
        thread.setName(name);
        return thread;
    }
}

用法:

Executors.newSingleThreadExecutor(new ThreadFactoryWithCustomName(
        Executors.defaultThreadFactory(),
        "customName")
    );

答案 12 :(得分:2)

这是我的定制工厂,为线程转储分析器提供自定义名称。通常我只是给tf=null重用JVM默认线程工厂。 This website has more advanced thread factory.

public class SimpleThreadFactory implements ThreadFactory {
    private ThreadFactory tf;
    private String nameSuffix;

    public SimpleThreadFactory (ThreadFactory tf, String nameSuffix) {
        this.tf = tf!=null ? tf : Executors.defaultThreadFactory();
        this.nameSuffix = nameSuffix; 
    }

    @Override public Thread newThread(Runnable task) {
        // default "pool-1-thread-1" to "pool-1-thread-1-myapp-MagicTask"
        Thread thread=tf.newThread(task);
        thread.setName(thread.getName()+"-"+nameSuffix);
        return thread;
    }
}

- - - - - 

ExecutorService es = Executors.newFixedThreadPool(4, new SimpleThreadFactory(null, "myapp-MagicTask") );

为方便起见,这是一个用于调试目的的线程转储循环。

    ThreadMXBean mxBean=ManagementFactory.getThreadMXBean();
    long[] tids = mxBean.getAllThreadIds();
    System.out.println("------------");
    System.out.println("ThreadCount="+tids.length);
    for(long tid : tids) {
        ThreadInfo mxInfo=mxBean.getThreadInfo(tid);
        if (mxInfo==null) {
            System.out.printf("%d %s\n", tid, "Thread not found");
        } else {
            System.out.printf("%d %s, state=%s, suspended=%d, lockowner=%d %s\n"
                    , mxInfo.getThreadId(), mxInfo.getThreadName()
                    , mxInfo.getThreadState().toString()
                    , mxInfo.isSuspended()?1:0
                    , mxInfo.getLockOwnerId(), mxInfo.getLockOwnerName()
            );
        }
    }

答案 13 :(得分:2)

我以前经常做类似下面的事情(需要guava库):

ThreadFactory namedThreadFactory = new ThreadFactoryBuilder().setNameFormat("SO-POOL-%d").build();
ExecutorService executorService = Executors.newFixedThreadPool(5,namedThreadFactory);

答案 14 :(得分:1)

我用来装饰现有工厂的本地Java核心解决方案:

public class ThreadFactoryNameDecorator implements ThreadFactory {
    private final ThreadFactory defaultThreadFactory;
    private final String suffix;

    public ThreadFactoryNameDecorator(String suffix) {
        this(Executors.defaultThreadFactory(), suffix);
    }

    public ThreadFactoryNameDecorator(ThreadFactory threadFactory, String suffix) {
        this.defaultThreadFactory = threadFactory;
        this.suffix = suffix;
    }

    @Override
    public Thread newThread(Runnable task) {
        Thread thread = defaultThreadFactory.newThread(task);
        thread.setName(thread.getName() + "-" + suffix);
        return thread;
    }
}

实际情况:

Executors.newSingleThreadExecutor(new ThreadFactoryNameDecorator("foo"));

答案 15 :(得分:1)

如果您只想更改单个线程执行器的名称,我发现将lambda用作线程工厂是最简单的。

Executors.newSingleThreadExecutor(runnable -> new Thread(runnable, "Your name"));

答案 16 :(得分:1)

就像已经回答的其他答案一样,您可以创建并使用自己的java.util.concurrent.ThreadFactory接口实现(不需要外部库)。 我在下面粘贴我的代码,因为它与以前的答案不同,因为它使用String.format方法并采用线程的基本名称作为构造函数参数:

import java.util.concurrent.ThreadFactory;

public class NameableThreadFactory implements ThreadFactory{
    private int threadsNum;
    private final String namePattern;

    public NameableThreadFactory(String baseName){
        namePattern = baseName + "-%d";
    }

    @Override
    public Thread newThread(Runnable runnable){
        threadsNum++;
        return new Thread(runnable, String.format(namePattern, threadsNum));
    }    
}

这是用法示例:

ThreadFactory  threadFactory = new NameableThreadFactory("listenerThread");        
final ExecutorService executorService = Executors.newFixedThreadPool(5, threadFactory);

答案 17 :(得分:1)

基于上面的一些评论,不同之处在于我只是使用了lambda

submittedPerson

答案 18 :(得分:1)

使用 Executors.defaultThreadFactory() 的现有功能但只设置名称:

<form className='form' onSubmit={handleSubmit}>

答案 19 :(得分:1)

我想我会给出一些简化的例子,这样选项就全在那里了:

唯一编号(也可以将其放入方法中):

AtomicInteger threadNum = new AtomicInteger(0);
ExecutorService e = Executors.newSingleThreadExecutor(r -> new Thread(r, "my-name-" + threadNum.incrementAndGet()));

唯一编号和“可能”唯一名称(如果您正在生成新的 Runnable 对象)。如果在一个被多次调用的方法中启动线程很有用,例如:

AtomicInteger threadNum = new AtomicInteger(0);
ExecutorService e = Executors.newSingleThreadExecutor(r -> new Thread(r, "my-name-" + threadNum.incrementAndGet() + "-" + r.hashCode()));

如果您每次需要一个带有静态变量的类时确实想要一个唯一名称(并且还可以在其中添加一个静态池编号前缀,请参阅其他答案)。

和 JDK < 8 中的等效项(您不需要为它创建新类,或者可以从方法中返回 ThreadFactory):

Executors.newSingleThreadExecutor(new ThreadFactory() {
      AtomicInteger threadCount = new AtomicInteger(0);

      @Override
      public Thread newThread(Runnable r) {
        return new Thread(r, "your-name-" + threadCount.getAndIncrement() + "-" + r.hashCode()); // could also use Integer.toHexString(r.hashCode()) for shorter
      }
    }));

并且可以将其变成将“you-name-”方面作为变量的方法。或者像其他答案一样使用带有构造函数的单独类。