common-pool2提供了3中对象池管理方式，它们的使用方式基本一样，这里以GenericObjectPool对象池为例介绍其使用方式，一般实现自己的对象池需要经过2个步骤 1.实现PooledObjectFactory接口:该接口是一种工厂模式，实现其目的是让对象池通过该工厂模式创建管理的对象 2.创建对象池(GenericObjectPool(PooledObjectFactory))实例 创建Conn对象池 我们假设Conn对象是一个建立TCP连接的对象，该对象的初始化时间平均为500ms，为了避免在程序中频繁创建Conn对象，我们需要借助对象池管理Conn对象实例 import org.slf4j.LoggerFactory; /** * common-pool2 使用方式 * <p/> * 假设这是一个建立TCP连接的对象，该对象的初始化时间平均为500ms，为了避免在程序中频繁创建Conn对象，我们需要借助对象池管理Conn对象实例 * * @author WangJun <wangjuntytl@163.com> * @version 1.0 15/10/28 * @since 1.6 */ public class Conn { /** * 记录对象的创建时间 */ private long createTime; /** * 初始化Conn对象，模拟创建Conn对象平均消耗500ms * @throws InterruptedException */ public Conn() throws InterruptedException { Thread.sleep(500); createTime = System.currentTimeMillis(); LoggerFactory.getLogger(getClass()).debug(" init conn suc... " + createTime); } /** * 报告Conn对象信息 */ public void report() { LoggerFactory.getLogger(getClass()).info("this is a available conn " + createTime); } } 利用工厂模式，使对象池通过该工厂模式创建管理的对象 package com.peaceful.pool.demo; 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; /** * common-pool2 使用方式 * <p/> * 为了使用common-pool2对象池管理，我们必须实现{@link org.apache.commons.pool2.PooledObjectFactory}或者其子类 * 这是一个工厂模式，告诉对象池怎样去创建要管理的对象 * <p/> * BasePooledObjectFactory 是对{@link org.apache.commons.pool2.PooledObjectFactory}的一个基本实现，我们可以继承该类，减少一些方法的实现 * <p/> * 在实现{@link org.apache.commons.pool2.PooledObjectFactory}接口时，我们一定要实现的接口方法是{@link PooledObjectFactory#makeObject()}方法。 * * @author WangJun <wangjuntytl@163.com> * @version 1.0 15/10/28 * @since 1.6 */ public class ConnFactory extends BasePooledObjectFactory<Conn> { /** * 间接实现{@link PooledObjectFactory#makeObject()}方法，表明怎样创建需要管理对象 */ @Override public Conn create() throws Exception { return new Conn(); } /** * 在common-pool2中为了统计管理的对象的一些信息，比如调用次数，空闲时间，上次使用时间等，需要对管理的对象进行包装，然后在放入到对象池中 * * @param obj 对象池要管理的对象 * @return 返回包装后的PooledObject对象 */ @Override public PooledObject<Conn> wrap(Conn obj) { return new DefaultPooledObject<Conn>(obj); } } 为了模拟的更真实，ConnPool池可以让使用者个性化配置 package com.peaceful.pool.demo; import org.apache.commons.pool2.impl.GenericObjectPoolConfig; /** * common-pool2 使用方式 * <p/> * {@link org.apache.commons.pool2.impl.GenericObjectPool}支持个性化配置，我们可以配置对象池中总共的对象数，最大、最小空闲对象数等等 * 这边继承{@link GenericObjectPoolConfig}是为了ConnPool也可以进行个性化的配置 * * @author WangJun <wangjuntytl@163.com> * @version 1.0 15/10/28 * @since 1.6 */ public class ConnPoolConfig extends GenericObjectPoolConfig { public ConnPoolConfig() { // defaults to make your life with connection pool easier :) setMinIdle(5); setTestOnBorrow(true); } } 有了创建对象的工厂，我们就可以创建一个对象池实例 package com.peaceful.pool.demo; import org.apache.commons.pool2.impl.GenericObjectPool; /** * common-pool2 使用方式 * <p/> * Conn对象管理池，这里利用GenericObjectPool作为对象池 * * @author WangJun <wangjuntytl@163.com> * @version 1.0 15/10/28 * @since 1.6 */ public class ConnPool extends GenericObjectPool<Conn> { /** * 调用{@link GenericObjectPool}的构造方法，构造ConnPool */ public ConnPool() { super(new ConnFactory(), new ConnPoolConfig()); } /** * 调用{@link GenericObjectPool}的构造方法，构造ConnPool */ public ConnPool(ConnPoolConfig connPoolConfig) { super(new ConnFactory(), connPoolConfig); } } 这样一个就完成了整个ConnPool的编码，下面我们在写一个demo，演示使用ConnPool public class ConnDemo { public static void main(String[] args) throws Exception { ConnPoolConfig connPoolConfig = new ConnPoolConfig(); connPoolConfig.setMinIdle(5); connPoolConfig.setMaxIdle(8); ConnPool connPool = new ConnPool(connPoolConfig); Conn conn1 = connPool.borrowObject(); Conn conn2 = connPool.borrowObject(); Conn conn3 = connPool.borrowObject(); Conn conn4 = connPool.borrowObject(); Conn conn5 = connPool.borrowObject(); conn1.report(); connPool.returnObject(conn1); conn2.report(); connPool.returnObject(conn2); conn3.report(); connPool.returnObject(conn3); conn4.report(); connPool.returnObject(conn4); conn5.report(); connPool.returnObject(conn5); conn5.report(); // 被归还的对象的引用，不可以在次归还 // java.lang.IllegalStateException: Object has already been retured to this pool or is invalid try { connPool.returnObject(conn5); }catch (Exception e){ e.printStackTrace(); } } } 下面是ConnDemo的运行结果 [2015-10-28 14:56:06 DEBUG] {com.peaceful.pool.demo.Conn:18}- init conn suc... [2015-10-28 14:56:07 DEBUG] {com.peaceful.pool.demo.Conn:18}- init conn suc... [2015-10-28 14:56:07 DEBUG] {com.peaceful.pool.demo.Conn:18}- init conn suc... [2015-10-28 14:56:08 DEBUG] {com.peaceful.pool.demo.Conn:18}- init conn suc... [2015-10-28 14:56:08 DEBUG] {com.peaceful.pool.demo.Conn:18}- init conn suc... [2015-10-28 14:56:08 INFO ] {com.peaceful.pool.demo.Conn:22}-this is a available conn 1446015366746 [2015-10-28 14:56:08 INFO ] {com.peaceful.pool.demo.Conn:22}-this is a available conn 1446015367346 [2015-10-28 14:56:08 INFO ] {com.peaceful.pool.demo.Conn:22}-this is a available conn 1446015367853 [2015-10-28 14:56:08 INFO ] {com.peaceful.pool.demo.Conn:22}-this is a available conn 1446015368354 [2015-10-28 14:56:08 INFO ] {com.peaceful.pool.demo.Conn:22}-this is a available conn 1446015368860 [2015-10-28 14:56:08 INFO ] {com.peaceful.pool.demo.Conn:22}-this is a available conn 1446015368860 java.lang.IllegalStateException: Object has already been retured to this pool or is invalid at org.apache.commons.pool2.impl.GenericObjectPool.returnObject(GenericObjectPool.java:595) at com.peaceful.pool.demo.ConnDemo.main(ConnDemo.java:37) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at com.intellij.rt.execution.application.AppMain.main(AppMain.java:140)