java newfixedthreadpool

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

public class FixedThreadPoolExample {
    public static void main(String[] args) {
        // 创建一个固定大小为5的线程池
        ExecutorService executor = Executors.newFixedThreadPool(5);

        for (int i = 0; i < 10; i++) {
            Runnable worker = new WorkerThread("" + i);
            executor.execute(worker);
        }
        executor.shutdown();
        while (!executor.isTerminated()) {
        }
        System.out.println("Finished all threads");
    }
}

class WorkerThread implements Runnable {
    private String command;

    public WorkerThread(String s) {
        this.command = s;
    }

    @Override
    public void run() {
        System.out.println(Thread.currentThread().getName() + " Start. Command = " + command);
        processCommand();
        System.out.println(Thread.currentThread().getName() + " End.");
    }

    private void processCommand() {
        try {
            Thread.sleep(500);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    @Override
    public String toString() {
        return this.command;
    }
}

import java.util.concurrent.*;

public class CustomThreadPool {
    public static void main(String[] args) {
        int corePoolSize = 5;
        int maxPoolSize = 10;
        long keepAliveTime = 5000;
        BlockingQueue<Runnable> workQueue = new ArrayBlockingQueue<>(10);
        RejectedExecutionHandler handler = new ThreadPoolExecutor.CallerRunsPolicy();

        ThreadPoolExecutor executor = new ThreadPoolExecutor(
                corePoolSize,
                maxPoolSize,
                keepAliveTime,
                TimeUnit.MILLISECONDS,
                workQueue,
                handler
        );

        // 提交任务...
    }
}

class WorkerThread implements Runnable {
    @Override
    public void run() {
        try {
            // 执行任务...
        } finally {
            // 释放资源...
        }
    }
}