Java Executors newFixedThreadPool() 方法

2025 年 3 月 25 日 | 阅读 2 分钟

Executors 类的 newFixedThreadPool() 方法创建一个线程池，该线程池通过共享的无界队列重用固定数量的线程。在任何时候，最多 n 个线程将处于活动状态来处理任务。当所有线程都处于活动状态时，如果提交了其他任务，它们将等待在队列中，直到有线程可用。

语法

public static ExecutorService newFixedThreadPool(int nThreads)
public static ExecutorService newFixedThreadPool(int nThreads, ThreadFactory threadFactory)

参数

nThreads - 池中的线程数

threadFactory - 创建新线程时使用的工厂

返回值

抛出

IllegalArgumentException

NullPointerException

示例 1

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

public class ExecutornewFixedThreadPoolExample1   {
    
   public static void main(final String[] arguments) throws InterruptedException {
      ThreadFactory ThreadFactory = Executors.defaultThreadFactory();
      ExecutorService excr = Executors.newFixedThreadPool(5 , ThreadFactory);
      ThreadPoolExecutor mypool = (ThreadPoolExecutor) excr;
      System.out.println("size of mypool: " + mypool.getPoolSize());
      excr.submit(new Threadimpl());
      excr.shutdown();
   }  

static class Threadimpl implements Runnable {
      public void run() {
         try {
            Long num = (long) (Math.random() * 30);
            System.out.println("Thread Name: " +Thread.currentThread().getName());
               TimeUnit.SECONDS.sleep(num);
            System.out.println("after sleep Thread Name: " +Thread.currentThread().getName());
         } catch (InterruptedException e) {
            e.printStackTrace();
         }
      }
   }

}

立即测试

输出

size of mypool: 0
Thread Name: pool-1-thread-1
after sleep Thread Name: pool-1-thread-1

示例 2

import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;

public class ExecutornewFixedThreadPoolExample2   {
    
   public static void main(final String[] arguments) throws InterruptedException {
      ExecutorService excr = Executors.newFixedThreadPool(5);
      ThreadPoolExecutor mypool = (ThreadPoolExecutor) excr;
      System.out.println("size of mypool: " + mypool.getPoolSize());
      excr.submit(new Threadimpl());
      excr.shutdown();
   }  

static class Threadimpl implements Runnable {
      public void run() {
         try {
            Long num = (long) (Math.random() * 30);
            System.out.println("Thread Name: " +Thread.currentThread().getName());
               TimeUnit.SECONDS.sleep(num);
            System.out.println("after sleep Thread Name: " +Thread.currentThread().getName());
         } catch (InterruptedException e) {
            e.printStackTrace();
         }
      }
   }

}

输出

size of mypool: 0
Thread Name: pool-1-thread-1
after sleep Thread Name: pool-1-thread-1

下一主题Java Executors

Java Executors newFixedThreadPool() 方法

语法

参数

返回值

抛出

示例 1

示例 2

联系信息

关注我们

教程

面试题

在线编译器

Python

Java

.Net Framework

AI, ML and Data Science

Cloud Technology

B.Tech and MCA

Web Technology

PHP

Software Testing

Technical Interview

Java Interview

Python

Web Interview

Database Interview

B.Tech / MCA

Important Interview

Software Testing Interview

Company Interviews

Online Compilers

Multiple Choice Questions

Java String 方法

Java 数组类

Java Math 方法

ArrayList 方法

Java List 方法

Java 线程方法

Java Date 类

Java Collection 方法

Java ListIterator 类

Java NIO 教程

HttpURLConnection

Java Deque

Java HttpCookie 类

Java URL 类

Java Vector 类

Java Socket 类

Java Executors

Java Integer 类

Java IdentityHashMap

Java ArrayBlockingQueue

Java Timestamp

Java Spliterator

Java Bitset

Java Instant

Java Compiler 类

Java AtomicInteger 类

Java AtomicLong 方法

Java Authenticator

Java BigDecimal 类

Big Integer 类

Java Boolean 类

Java Byte Class

Java Class

Java Collections 类

CopyOnWriteArrayList

LinkedBlockingDeque

Java Long 类

LinkedTransferQueue

Java List

Java MulticastSocket

Java Number 类

Java Phaser 类

Java Executors newFixedThreadPool() 方法

语法

参数

返回值

抛出

示例 1

示例 2

相关帖子

Executors newCachedThreadPool()

newWorkStealingPool()

Executors newSingleThreadExecutor()

Java Executors

ExecutorsnewScheduledThreadPool()

Executors privilegedThreadFactory()

Executors callable()

Executors defaultThreadFactory()

订阅 Tpoint Tech

联系信息