命名ExecutorService的线程和线程池

假设我有一个利用该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）名称创建线程：Thread[pool-1-thread-1]。如您所见，这并不是非常有用，而且据我所知，该Executor框架没有提供一种简便的方法来命名已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]。

你可以提供一个ThreadFactory到newSingleThreadScheduledExecutor(ThreadFactory threadFactory)。工厂将负责创建线程，并将能够为其命名。

引用Javadoc：

创建新线程

使用创建新线程ThreadFactory。如果没有另外指定，Executors.defaultThreadFactory()则使用a，它将创建所有线程，并且所有线程都ThreadGroup具有相同的NORM_PRIORITY优先级和非守护程序状态。通过提供其他参数ThreadFactory，您可以更改线程的名称，线程组，优先级，守护程序状态等。如果在ThreadFactory从返回null时被要求创建线程失败newThread，执行器将继续执行，但可能无法执行任何任务

番石榴几乎总能满足您的需求。

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

并传递给你的朋友ExecutorService。

您可以尝试提供自己的线程工厂，该工厂将使用适当的名称创建线程。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);

执行线程后，还可以在之后更改线程的名称：

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

例如，如果您将同一ThreadFactory用于不同类型的任务，则可能会对此感兴趣。

在BasicThreadFactoryApache的公地郎也提供命名行为非常有用。无需编写匿名内部类，而是可以使用Builder随意命名线程。这是来自javadocs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);

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

例：

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

另外，您也可以ExecutorService使用ThreadPoolExecutorFactoryBean-将其创建为Spring Bean ，然后所有线程都将以beanName-前缀命名。

@Bean
public ThreadPoolExecutorFactoryBean myExecutor() {
    ThreadPoolExecutorFactoryBean executorFactoryBean = new ThreadPoolExecutorFactoryBean();
    // configuration of your choice
    return executorFactoryBean;
}

在上面的示例中，线程将以myExecutor-前缀命名。您可以"myPool-"通过executorFactoryBean.setThreadNamePrefix("myPool-")在工厂bean上进行设置，将前缀显式设置为其他值（例如）。

Oracle为此提供了开放的RFE。从Oracle员工的评论看来，他们似乎不了解该问题，也无法解决。在JDK中支持这些事情非常简单（不破坏向后兼容性），因此RFE被误解有点可耻。

如前所述，您需要实现自己的ThreadFactory。如果您不想为此目的引入Guava或Apache Commons，我在这里提供ThreadFactory您可以使用的实现。它除了可以将线程名称前缀设置为“ pool”以外的其他内容外，与从JDK获得的内容完全相似。

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;
    }
}

当您要使用它时，您只需利用所有Executors方法都可以提供自己的方法这一事实ThreadFactory。

这个

    Executors.newSingleThreadExecutor();

将提供一个ExecutorService，其中pool-N-thread-M通过使用来命名线程

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

您将获得一个ExecutorService，其中的线程名为primecalc-N-thread-M。瞧！

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，您就可以开始工作了

一种快速而肮脏的方法是Thread.currentThread().setName(myName);在该run()方法中使用。

扩展 ThreadFactory

public interface ThreadFactory

根据需要创建新线程的对象。使用线程工厂可以消除对新线程的调用的繁琐工作，从而使应用程序可以使用特殊的线程子类，优先级等。

Thread newThread(Runnable r)

构造一个新的线程。实现也可以初始化优先级，名称，守护程序状态，ThreadGroup等。

样例代码：

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

....等等

正如其他答案所言，您可以创建并使用自己的 java.util.concurrent.ThreadFactory接口（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，并以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);

编辑：使我的ThreadFactory实现线程安全，感谢@mchernyakov指出它。
即使在ThreadFactory文档中没有任何地方说其实现必须是线程安全的，但事实DefaultThreadFactory是线程安全是一个很大的提示：

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

public class NameableThreadFactory implements ThreadFactory{
    private final AtomicInteger threadsNum = new AtomicInteger();

    private final String namePattern;

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

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

实际上：

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

Executors.newSingleThreadExecutor(r -> new Thread(r, "someName")).submit(getJob());

Runnable getJob() {
        return () -> {
            // your job
        };
}

您可以编写自己的ThreadFactory实现，例如使用一些现有实现（例如defaultThreadFactory）并在末尾更改名称。

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;
    }
}

和用法：

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

我经常像下面那样做（需要guava库）：

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

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"));

这是我的定制工厂，为线程转储分析器提供了定制名称。通常我只是给tf=null重用JVM默认线程工厂。该网站具有更高级的线程工厂。

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") );

为了您的方便，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()
            );
        }
    }