Java在超时后释放Poolable对象

Question

我一直在寻找池化对象的方法，如果 X 分钟内不使用该对象，它将从对象池中删除。

这个 Poolable 对象是到遗留系统的套接字连接。我只需要一个持久连接，当需要新连接时，会创建更多对象来满足该需求。但我只希望这些新的非持久对象连接在最后一个请求后持续大约 5 分钟，然后优雅地断开连接。

我不确定 Apache Commons Pool 项目是否可以在这里提供帮助。

如何设置这种“创建/发布”规则？它是 Apache Commons Pool 的一部分，还是我的对象必须自己处理它？我真的不确定。

-以色列

Answer 1

为了 future 读者的利益，我使用 commons pool2 编写了一个小型实现:

package com.test.communicator;

import org.apache.commons.pool2.BasePooledObjectFactory;
import org.apache.commons.pool2.PooledObject;
import org.apache.commons.pool2.PooledObjectFactory;
import org.apache.commons.pool2.impl.DefaultPooledObject;
import org.apache.commons.pool2.impl.GenericObjectPool;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig;

public class Test {
    
    public void initializePool() throws Exception {
        GenericObjectPoolConfig config = new GenericObjectPoolConfig();
        
        // parameters for the life cycle of the objects
        config.setMinIdle(1);
        config.setMaxIdle(1);
        config.setMaxTotal(1);

        // if the object is not accessed in 5 minutes, it evicted (throw away from the pool)
        config.setTimeBetweenEvictionRunsMillis(5 * 60 * 1000);
        // frequency at which it check for objects to be evicted
        config.setMinEvictableIdleTimeMillis(1 * 60 * 1000);
        
        CommonsObjectPool pool = new CommonsObjectPool(new MyObjectPoolFactory(), config);
        
        MyObject myObj = pool.borrowObject(); //borrow an object
    }
    
    /**
     * An object pool implementation of your objects
     */
    class CommonsObjectPool extends GenericObjectPool<MyObject> {

        public CommonsObjectPool(PooledObjectFactory<MyObject> factory) {
            super(factory);
        }

        public CommonsObjectPool(PooledObjectFactory<MyObject> factory, GenericObjectPoolConfig config) {
            super(factory, config);
        }
    }
    
    
    
    /**
     * Factory to create the objects
     */
    class MyObjectPoolFactory extends BasePooledObjectFactory<MyObject> {
        @Override
        public MyObject create() throws Exception {
            // create your object
            return new MyObject();
        }

        @Override
        public PooledObject<MyObject> wrap(MyObject arg0) {
            return new DefaultPooledObject<MyObject>(arg0);
        }

        @Override
        public boolean validateObject(PooledObject<MyObject> pooledObj) {
            return pooledObj.getObject().isMyObjectValid(); // implement a validation
        }

        @Override
        public void destroyObject(PooledObject<MyObject> pooledObj) throws Exception {
            // clean up the object
            //pooledObj.getObject().close ()
        }
    }   
    
    class MyObject {
        public boolean isMyObjectValid() {
            return true;
        }
        
        public void close () {
         // clean up the object
        }
    }
}

下面两行提供了您正在寻找的功能。

    // if the object is not accessed in 5 minutes, it evicted (throw away from the pool)
    config.setTimeBetweenEvictionRunsMillis(5 * 60 * 1000);
    // frequency at which it check for objects to be evicted
    config.setMinEvictableIdleTimeMillis(1 * 60 * 1000);