commons-pool对象池实例（一）

使用commons-pool 框架实现了一个对象池例子。将官网的例子稍微改动了一下而已。

使用的版本是：

<dependency>
	<groupId>org.apache.commons</groupId>
	<artifactId>commons-pool2</artifactId>
	<version>2.4.2</version>
</dependency>

 

 

对象池实现类：

 

package com.my.pool.pooledobject;

import org.apache.commons.pool2.ObjectPool;

public class PooledStringBuffer {
	private ObjectPool<StringBuffer> pool;
	
	public PooledStringBuffer(ObjectPool<StringBuffer> pool) {
		this.pool = pool;
	}
	
	public boolean print(String data) {
		boolean flag = false;
		if(pool!=null) {
			StringBuffer buf = null;
			try{
				buf = pool.borrowObject();
				buf.append(data);
				System.out.println(buf.toString());
				return true;
			}catch(Exception e) {
				e.printStackTrace();
			}finally {
				try {
					pool.returnObject(buf);
				} catch (Exception e) {
					e.printStackTrace();
				}
			}
		}
		
		return flag;
	}
	
}

 

对象池的工厂：

package com.my.pool.pooledobject;

import org.apache.commons.pool2.BasePooledObjectFactory;
import org.apache.commons.pool2.PooledObject;
import org.apache.commons.pool2.impl.DefaultPooledObject;

/**
 * 先创建，后打包
 *
 */
public class PooledStringBufferFactory extends BasePooledObjectFactory<StringBuffer>{

	@Override
	public StringBuffer create() throws Exception {
		return new StringBuffer();
	}

	@Override
	/**
	 * 打包成一个可以调度的对象
	 */
	public PooledObject<StringBuffer> wrap(StringBuffer obj) {
		return new DefaultPooledObject<StringBuffer>(obj);
	}
	
	@Override
	/**
	 * 归还后调用的方法
	 */
	public void passivateObject(PooledObject<StringBuffer> pooledObject) {
		pooledObject.getObject().setLength(0);
	}

}

 

主类：

package com.my.pool.main;

import org.apache.commons.pool2.impl.GenericObjectPool;
import org.apache.commons.pool2.impl.GenericObjectPoolConfig;

import com.my.pool.pooledobject.PooledStringBuffer;
import com.my.pool.pooledobject.PooledStringBufferFactory;

public class MainClass {
	public static void main(String[] args) {
		GenericObjectPoolConfig config = new GenericObjectPoolConfig();
		//最长等待分配时间
		config.setMaxWaitMillis(1000l);
		//池内最多对象数
		config.setMaxTotal(100);
		//池内最大空闲数目
		config.setMaxIdle(20);
		//池内最小空闲数目
		config.setMinIdle(10);
		
		GenericObjectPool<StringBuffer> pool = new GenericObjectPool<StringBuffer>(new PooledStringBufferFactory(), config);
		
		PooledStringBuffer bufUtil = new PooledStringBuffer(pool);
		bufUtil.print("OK");
	}
}

 

    对象池可以应用于数据库连接池的管理，可以重复利用对象，提高性能。实际应用中使用spring进行配置管理会更方便