命名ExecutorService的线程和线程池-Java 学习之路

179

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 框架并没有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] .

14 回答

Guava 几乎总是有你的need .

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

把它传递给你 ExecutorService .

回复于 2024-04-24T20:38:48+08:00

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);

回复于 2024-04-24T20:38:48+08:00

8
您还可以在执行线程时更改线程的名称：
```
Thread.currentThread().setName("FooName");
```
例如，如果您将不同类型的任务用于相同的ThreadFactory，那么这可能是有意义的 .
回复于 2024-04-24T20:38:48+08:00
6

你可以提供ThreadFactory到newSingleThreadScheduledExecutor(ThreadFactory threadFactory) . 工厂将负责创建线程，并且能够命名它们 .

引用Javadoc：

创建新线程使用ThreadFactory创建新线程 . 如果没有另外指定，则使用Executors.defaultThreadFactory（），它将所有线程创建在同一个ThreadGroup中，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在通过从newThread返回null请求时无法创建线程，则执行程序将继续，但可能无法执行任何任务

回复于 2024-04-24T20:38:48+08:00

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 . 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);

回复于 2024-04-24T20:38:48+08:00

对于Oracle来说，这是一个open RFE . 根据Oracle员工的评论，似乎他们没有解决问题 . 这是JDK中支持简单易用的东西之一（没有破坏向后兼容性），因此RFE被误解是一种耻辱 .

正如所指出的，你需要实现自己的ThreadFactory . 如果你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你可以使用的 ThreadFactory 实现 . 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"pool"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 .

这个

Executors.newSingleThreadExecutor();

将给出一个ExecutorService，其中线程名为 pool-N-thread-M 但是使用了

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

你会得到一个ExecutorService，其中的线程名为 primecalc-N-thread-M . 瞧！

回复于 2024-04-24T20:38:48+08:00

45
如果您使用的是Spring，则可以使用CustomizableThreadFactory设置线程名称前缀 .

例：
```
ExecutorService alphaExecutor =
    Executors.newFixedThreadPool(10, new CustomizableThreadFactory("alpha-"));
```
回复于 2024-04-24T20:38:48+08:00

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 Actuator 服务器，你很高兴

回复于 2024-04-24T20:38:48+08:00

237

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

回复于 2024-04-24T20:38:48+08:00

延长ThreadFactory

public interface ThreadFactory

按需创建新线程的对象 . 使用线程工厂删除了对新线程的调用的硬连接，使应用程序能够使用特殊的线程子类，优先级等 .

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

....等等

回复于 2024-04-24T20:38:48+08:00

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

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

回复于 2024-04-24T20:38:48+08:00

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")
    );

回复于 2024-04-24T20:38:48+08:00

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默认的线程工厂 . 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()
            );
        }
    }

回复于 2024-04-24T20:38:48+08:00

我用来做同样的事情（需要 guava 库）：

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

回复于 2024-04-24T20:38:48+08:00

命名ExecutorService的线程和线程池

14 回答

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