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

public class ThreadPoolExecutorExample {
    static class OOMClass {
        // 創(chuàng)建 1MB 大小的變量（1M = 1024KB = 1024*1024Byte）
        private byte[] data_byte = new byte[1 * 1024 * 1024];
    }
    public static void main(String[] args) throws InterruptedException {
        // 使用執(zhí)行器自動(dòng)創(chuàng)建線程池
        ExecutorService threadPool = Executors.newCachedThreadPool();
        List<Object> list = new ArrayList<>();
        // 添加任務(wù)
        for (int i = 0; i < 10; i++) {
            int finalI = i;
            threadPool.execute(new Runnable() {
                @Override
                public void run() {
                    // 定時(shí)添加
                    try {
                        Thread.sleep(finalI * 200);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    // 將 1M 對(duì)象添加到集合
                    OOMClass oomClass = new OOMClass();
                    list.add(oomClass);
                    System.out.println("執(zhí)行任務(wù)：" + finalI);
                }
            });
        }
    }
}

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.*;
/**
 * ThreadPoolExecutor 演示示例
 */
public class ThreadPoolExecutorExample {
    static class OOMClass {
        // 創(chuàng)建 1MB 大小的變量（1M = 1024KB = 1024*1024Byte）
        private byte[] data_byte = new byte[1 * 1024 * 1024];
    }

    public static void main(String[] args) throws InterruptedException {
        // 手動(dòng)創(chuàng)建線程池，最大線程數(shù) 2，最多存儲(chǔ) 2 個(gè)任務(wù)，其他任務(wù)會(huì)被忽略
        ThreadPoolExecutor threadPool = new ThreadPoolExecutor(2, 2,
                0L, TimeUnit.SECONDS, new LinkedBlockingQueue<>(2),
                new ThreadPoolExecutor.DiscardPolicy()); // 拒絕策略：忽略任務(wù)
        List<Object> list = new ArrayList<>();
        // 添加任務(wù)
        for (int i = 0; i < 10; i++) {
            int finalI = i;
            threadPool.execute(new Runnable() {
                @Override
                public void run() {
                    // 定時(shí)添加
                    try {
                        Thread.sleep(finalI * 200);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    // 將 1m 對(duì)象添加到集合
                    OOMClass oomClass = new OOMClass();
                    list.add(oomClass);
                    System.out.println("執(zhí)行任務(wù)：" + finalI);
                }
            });
        }
        // 關(guān)閉線程池
        threadPool.shutdown();
        // 檢測(cè)線程池的任務(wù)執(zhí)行完
        while (!threadPool.awaitTermination(3, TimeUnit.SECONDS)) {
            System.out.println("線程池中還有任務(wù)在處理");
        }
    }
}