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如何从线程池中获取线程id?

executors executorservice threadpool multithreading java

122

serg · 技术社区 · 16 年前

我有一个固定的线程池,可以将任务提交给它(仅限于 5 5 5 正在执行此任务“)?

ExecutorService taskExecutor = Executors.newFixedThreadPool(5);

//in infinite loop:
taskExecutor.execute(new MyTask());
....

private class MyTask implements Runnable {
    public void run() {
        logger.debug("Thread # XXX is doing this task");//how to get thread id?
    }
}

6 回复 | 直到 10 年前

245

skaffman 16 年前

使用 Thread.currentThread() :

private class MyTask implements Runnable {
    public void run() {
        long threadId = Thread.currentThread().getId();
        logger.debug("Thread # " + threadId + " is doing this task");
    }
}

Burhan Ali 12 年前

公认的答案回答了关于获得一线程id,但它不允许您执行“线程X/Y”消息。线程ID在线程之间是唯一的,但不一定从0或1开始。

import java.util.concurrent.*;
class ThreadIdTest {

  public static void main(String[] args) {

    final int numThreads = 5;
    ExecutorService exec = Executors.newFixedThreadPool(numThreads);

    for (int i=0; i<10; i++) {
      exec.execute(new Runnable() {
        public void run() {
          long threadId = Thread.currentThread().getId();
          System.out.println("I am thread " + threadId + " of " + numThreads);
        }
      });
    }

    exec.shutdown();
  }
}

以及输出:

burhan@orion:/dev/shm$ javac ThreadIdTest.java && java ThreadIdTest
I am thread 8 of 5
I am thread 9 of 5
I am thread 10 of 5
I am thread 8 of 5
I am thread 9 of 5
I am thread 11 of 5
I am thread 8 of 5
I am thread 9 of 5
I am thread 10 of 5
I am thread 12 of 5

使用模运算稍微调整一下,就可以正确地执行“线程X/Y”:

// modulo gives zero-based results hence the +1
long threadId = Thread.currentThread().getId()%numThreads +1;

新结果:

burhan@orion:/dev/shm$ javac ThreadIdTest.java && java ThreadIdTest  
I am thread 2 of 5 
I am thread 3 of 5 
I am thread 3 of 5 
I am thread 3 of 5 
I am thread 5 of 5 
I am thread 1 of 5 
I am thread 4 of 5 
I am thread 1 of 5 
I am thread 2 of 5 
I am thread 3 of 5

Vineet Reynolds 16 年前

您可以使用Thread.getCurrentThread.getId(),但为什么要在 LogRecord 由记录器管理的对象已经具有线程Id。我认为您在某个地方缺少一个用于记录日志消息的线程Id的配置。

Vitaliy Polchuk 9 年前

线程工厂有助于:

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadFactory;

public class Main {

    static Logger LOG = LoggerFactory.getLogger(Main.class);

    static class MyTask implements Runnable {
        public void run() {
            LOG.info("A pool thread is doing this task");
        }
    }

    public static void main(String[] args) {
        ExecutorService taskExecutor = Executors.newFixedThreadPool(5, new MyThreadFactory());
        taskExecutor.execute(new MyTask());
        taskExecutor.shutdown();
    }
}

class MyThreadFactory implements ThreadFactory {
    private int counter;
    public Thread newThread(Runnable r) {
        return new Thread(r, "My thread # " + counter++);
    }
}

输出:

[   My thread # 0] Main         INFO  A pool thread is doing this task

Justin Ethier 16 年前

如果您的类继承自 Thread ,可以使用方法 getName 和 setName name 字段到 MyTask ,并在构造函数中初始化它。

Joshua Pinter 6 年前

当前线程的获取方式有:

Thread t = Thread.currentThread();

线程ID获取:

long tId = t.getId(); // e.g. 14291

线程名称获取:

String tName = t.getName(); // e.g. "pool-29-thread-7"