執行緒池引數及執行順序詳解ExecutorService

執行緒池引數及執行順序詳解ExecutorService

import com.google.common.util.concurrent.ThreadFactoryBuilder;
import java.util.concurrent.*;

/**
 * corePoolSize：執行緒池核心執行緒數，也是初始化執行緒數，優先使用corePoolSize。
 * keepAliveTime：執行緒空閒達到空閒時間回收到執行緒池。
 * BlockingQueue：當corePoolSize用完，先進佇列，此時maximumPoolSize沒有用
 * maximumPoolSize：佇列滿了，且執行執行緒數小於最大執行緒數，建立新的執行緒
 * 
 * BlockingQueue：核心執行緒用完，佇列滿了，做大執行緒數建立到了，再有新的任務過來，這時候採用拒絕策略，
 * 拒絕策略：1.預設丟擲異常AbortPolicy；2.DiscardPolicy拒絕任務不拋異常，3.DiscardOldestPolicy彈出最先的新增進去
 * 
 * @since 1.0
 */
public class ExecutorTest {

    private static ThreadFactory namedThreadFactory = new ThreadFactoryBuilder().setNameFormat("adsytfs-pool-%d").build();
    private static ExecutorService pool = new ThreadPoolExecutor(2, 3, 60L, TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(1)
            , namedThreadFactory, new ThreadPoolExecutor.AbortPolicy());

    public static void main(String[] args) {

        //任務1
        pool.execute(new Runnable() {
            @Override
            public void run() {
                try {
                    //主執行緒睡2秒
                    Thread.sleep(2 * 1000);
                    System.out.println("-------------helloworld_001---------------" + Thread.currentThread().getName());
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        });

        //任務2
        pool.execute(new Runnable() {
            @Override
            public void run() {
                try {
                    //主執行緒睡5秒
                    Thread.sleep(5 * 1000);
                    System.out.println("-------------helloworld_002---------------" + Thread.currentThread().getName());
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        });

        // 任務3
        pool.execute(new Runnable() {
            @Override
            public void run() {
                System.out.println("-------------helloworld_003---------------" + Thread.currentThread().getName());
            }
        });

        // 任務4
        pool.execute(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(2 * 1000);
                    System.out.println("-------------helloworld_004---------------" + Thread.currentThread().getName());
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        });

        // 任務5
        pool.execute(new Runnable() {
            @Override
            public void run() {
                System.out.println("-------------helloworld_005---------------" + Thread.currentThread().getName());
            }
        });

    }

}