java - 未使用 ObjectPool 打开非法状态异常池

Question

我正在尝试学习如何使用池连接，这样我就可以通过不必打开/关闭服务器的通道来获得更好的吞吐量，但我似乎无法让它工作。我有一个稍微修改过的代码版本，当我分叉一个线程并让每个线程运行一个循环来转储数据时，它可以工作，但现在我试图用ThreadPoolExecutor一个线程发送作业，然后产生 2 个线程来处理工作。我的实验应该希望在任何给定时间显示大约 2 个通道打开（或尽可能多的线程），但是当我更改代码时，我得到illegalstateexception: pool not open

如果我的池设计错误或者我对 ThreadPoolExecutor 的理解有缺陷，我真的很困惑。我对 ThreadPoolExecutor 的理解是，如果有工作要做，它会让线程保持活动状态，并且不会在每次迭代时继续杀死/重新生成它们。

这是代码（你可以忽略所有rabbitmq的东西，它的要点是你需要打开一个到服务器的连接，然后打开一个通道。我试图打开一个到服务器的连接，然后是一个通道池共享）。我的想法是创建 objectpool 类的实例，然后borrows根据需要将其传递给可运行的通道。

代码：

import org.apache.commons.pool.BasePoolableObjectFactory;
import org.apache.commons.pool.ObjectPool;
import org.apache.commons.pool.PoolableObjectFactory;
import org.apache.commons.pool.impl.GenericObjectPool;

import java.io.IOException;
import java.util.NoSuchElementException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;


import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.MessageProperties;

public class PoolExample {

    private static ExecutorService executor_worker;
    static {
        final int numberOfThreads_ThreadPoolExecutor = 2;
        executor_worker =
            new ThreadPoolExecutor(numberOfThreads_ThreadPoolExecutor, numberOfThreads_ThreadPoolExecutor, 1000, TimeUnit.SECONDS,
                                   new LinkedBlockingDeque<Runnable>());   
    }

    public static void main(String[] args) throws Exception {
        System.out.println("starting..");       
        PoolableObjectFactory<MyPooledObject> factory = new MyPoolableObjectFactory();
        ObjectPool<MyPooledObject> pool = new GenericObjectPool<MyPooledObject>(factory);
        for (int x = 0; x<500000000; x++) {
            executor_worker.submit(new Thread(new MyRunnable(x, pool)));
        }
    }
}

class MyPooledObject {
    //Connection connection;
    Channel channel;
    public MyPooledObject() throws IOException {
        System.out.println("hello world");
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        Connection connection = factory.newConnection();
        channel = connection.createChannel(); 
    }

    public Channel sing() throws IOException {
        //System.out.println("mary had a little lamb");
        return channel;
    }

    public void destroy() {
        System.out.println("goodbye cruel world");      
    }
}

class MyPoolableObjectFactory extends BasePoolableObjectFactory<MyPooledObject> {
    @Override
    public MyPooledObject makeObject() throws Exception {
        return new MyPooledObject();
    }
    @Override
    public void destroyObject(MyPooledObject obj) throws Exception {
        obj.destroy();
    }
}

class MyRunnable implements Runnable{  
    protected int x = 0;
    protected ObjectPool<MyPooledObject> pool = null;

    public MyRunnable(int x, ObjectPool<MyPooledObject> pool) {
        // TODO Auto-generated constructor stub
        this.x = x;
        this.pool = pool;
    }

    public void run(){
        try {
                MyPooledObject obj;
                obj = pool.borrowObject();
                Channel channel = obj.sing();
                String message = Integer.toString(x);
                channel.basicPublish( "", "task_queue", 
                        MessageProperties.PERSISTENT_TEXT_PLAIN,
                        message.getBytes());
                pool.returnObject(obj);
        } catch (NoSuchElementException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            try {
                pool.close();
            } catch (Exception e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}

知道我的设计有什么问题吗？还是我整个池对象的方法有缺陷？

UPDATE1：根据请求，这里是堆栈跟踪（我连续得到很多）：

堆栈跟踪：

java.lang.IllegalStateException: Pool not open
    at org.apache.commons.pool.BaseObjectPool.assertOpen(BaseObjectPool.java:140)
    at org.apache.commons.pool.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:1079)
    at MyRunnable.run(PoolExample.java:85)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
    at java.util.concurrent.FutureTask.run(FutureTask.java:138)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:680)

如果有帮助，我的代码中的第 85 行（触发此错误的位置是）：obj = pool.borrowObject();

UPDATE2：很奇怪。我收到错误消息，但它确实将 2 个项目写入队列。我不想让任何人去追逐野鹅，但我认为这意味着它可以在创建对象时成功借用对象，但在将它们返回到池中时却不能？

UPDATE3：我设计了代码，所以它不会经过我上面的中间步骤。我不再收到错误消息，但它基本上什么也没做……我启动了 10 个线程并期望有 10 个通道，但我只得到 1 个通道几秒钟，然后它也关闭了。代码：

import org.apache.commons.pool.BasePoolableObjectFactory;
import org.apache.commons.pool.ObjectPool;
import org.apache.commons.pool.PoolableObjectFactory;
import org.apache.commons.pool.impl.GenericObjectPool;

import java.io.IOException;
import java.util.NoSuchElementException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;


import com.rabbitmq.client.ConnectionFactory;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.MessageProperties;

public class PoolExample {

    private static ExecutorService executor_worker;
    static {
        final int numberOfThreads_ThreadPoolExecutor = 20;
        executor_worker =
            new ThreadPoolExecutor(numberOfThreads_ThreadPoolExecutor, numberOfThreads_ThreadPoolExecutor, 1000, TimeUnit.SECONDS,
                                   new LinkedBlockingDeque<Runnable>());   
    }

    public static void main(String[] args) throws Exception {
        System.out.println("starting..");           
        ObjectPool<Channel> pool =
                new GenericObjectPool<Channel>(
                new ConnectionPoolableObjectFactory(), 5);

        for (int x = 0; x<500000000; x++) {
            executor_worker.submit(new MyRunnable(x, pool));
        }
        executor_worker.shutdown();
        pool.close();
    }
}

 class ConnectionPoolableObjectFactory extends BasePoolableObjectFactory<Channel> {
     Channel channel;

    public ConnectionPoolableObjectFactory() throws IOException {
        System.out.println("hello world");
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        Connection connection = factory.newConnection();
        channel = connection.createChannel(); 
    }

    @Override
    public Channel makeObject() throws Exception {                
        return channel;
    }

    @Override
    public boolean validateObject(Channel channel) {
        return channel.isOpen();
    }

    @Override
    public void destroyObject(Channel channel) throws Exception {
        channel.close();
    }

    @Override
    public void passivateObject(Channel channel) throws Exception {
        //System.out.println("sent back to queue");
    }
}

class MyRunnable implements Runnable{  
    protected int x = 0;
    protected ObjectPool<Channel> pool;

    public MyRunnable(int x, ObjectPool<Channel> pool) {
        // TODO Auto-generated constructor stub
        this.x = x;
        this.pool = pool;
    }

    public void run(){
        try {
                Channel channel = pool.borrowObject();
                String message = Integer.toString(x);
                channel.basicPublish( "", "task_queue", 
                        MessageProperties.PERSISTENT_TEXT_PLAIN,
                        message.getBytes());
                pool.returnObject(channel);
        } catch (NoSuchElementException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } 
    }
}