对RAM做简单的池化实现
首先由于项目的关系需要使用IBM的Rational Assert Manager做ROA的资源存储。所以需要编写一个队RAM进行池化的东西。大致实现类似JDBC下DBCP的功能。当然这里记录下的只是利用pool进行简单池化，并没有添加其他额外的功能。后期在使用中可能会增强该方法的功能。
首先列出该池化实现的需要jar：
junit-4.8.2.jar
log4j-1.2.16.jar
commons-pool-1.6.jar
com.ibm.ram.common_7.5.1.v20110224.jar
ramclient-ant.jar
ramclient.jar
首先pool中主要有三个接口：ObjectPool，ObjectPoolFactory和PoolableObjectFactory。这一组接口是基于Object的，而相对的还有一组也是三个接口就是基于KeyObject，底层使用Map实现。这里我们不需要使用Map的这种数据结构，所以只选择了Object讲解。
而ObjectPool接口implement后，主要就是用于实现池存储的功能。
ObjectPoolFactory这个接口主要是用于池的创建。当需要批量创建配置相同的池时，可以实现该工厂接口去批量穿件ObjectPool。
PoolableObjectFactory这个接口主要就是对我们需要池化的对象的创建，销毁，挂起，和激活等操作的管理工厂。
而pool包中，已经implement了以上接口实现了部分类。我们只需要通过继承那些类，稍作添加一些功能和重写一些方法即可。这种方式也是最简单实用的方式。不用自己去实现一些存储的实现。
而这里对于Object的，有genericObject和stackObject。两者只是存储的方式不同而已。前者使用arraylist实现，后者使用stack实现。本人选择arraylist实现的genericObject系列。作为池子的父类。
public class RAMObjectPool extends GenericObjectPool<RAMSession> {public RAMObjectPool() {super();}public RAMObjectPool(PoolableRAMObjectFactory factory) {super(factory);}public RAMObjectPool(PoolableRAMObjectFactory factory,Config config) {super(factory, config);}@Overridepublic RAMSession borrowObject() throws Exception {return borrowObject();}@Overridepublic void invalidateObject(RAMSession obj) throws Exception {invalidateObject(obj);}@Overridepublic void returnObject(RAMSession obj) throws Exception {returnObject(obj);}public class PoolableRAMObjectFactory extends BasePoolableObjectFactory<RAMSession> {private static Logger logger = Logger.getLogger(PoolableRAMObjectFactory.class);private String url = null;private String userId = null;private String userPwd = null;public PoolableRAMObjectFactory(String ramURL, String ramUserID, String ramPassword) {url = ramURL;userId = ramUserID;userPwd = ramPassword;}/** * create a RAMSession * @return * @throws Exception */@Overridepublic RAMSession makeObject() throws Exception {// Create a connection to Rational Asset Manager RAMSession session = new RAMSession(url,userId, userPwd); if(logger.isDebugEnabled())logger.debug("obj is created");return session;}/** * * @param obj * @return */@Overridepublic boolean validateObject(RAMSession obj) {return true;}@Overridepublic void destroyObject(RAMSession obj) throws Exception {if(obj!=null) {if(logger.isDebugEnabled())logger.debug("obj is destroyed");obj.release();obj = null;}}@Overridepublic void activateObject(RAMSession obj) throws Exception {}@Overridepublic void passivateObject(RAMSession obj) throws Exception {if (obj!=null) {if(logger.isDebugEnabled())logger.debug("obj is cleared");obj.clear();obj = null;}}}public class RAMSessionManager {private static Logger logger = Logger.getLogger(RAMSessionManager.class);private RAMObjectPool objectPool = null;private ThreadLocal<RAMSession> localSession = new ThreadLocal<RAMSession>();private RAMSessionManager() {GenericObjectPool.Config config = null;Properties properties = BaseConfig.load();String ramURL = properties.getProperty("ramURL");String ramUserID = properties.getProperty("ramUserID");String ramPassword = properties.getProperty("ramPassword");try {config = LoadObjectPoolConfig.load(properties.getProperty("poolConfigURL"));} catch (Exception e) {config = null;}if(config==null) {objectPool = new RAMObjectPool(new PoolableRAMObjectFactory(ramURL, ramUserID, ramPassword));} else {objectPool = new RAMObjectPool(new PoolableRAMObjectFactory(ramURL, ramUserID, ramPassword),config);}printDebugInfo();}static class RAMSessionHolder {public static RAMSessionManager instance = new RAMSessionManager();}public static RAMSessionManager getInstance() {return RAMSessionHolder.instance;}/** * create session * @return * @throws Exception */public RAMSession createSession() throws Exception {RAMSession obj = objectPool.borrowObject();if(obj!=null) {printDebugInfo();localSession.set(obj);} else {throw new NullPointerException("RAMSession is null from pool!");}return obj;}/** * if created Session get it, else create Session * @return * @throws Exception */public RAMSession openSession() throws Exception {RAMSession obj = localSession.get();if(obj==null) {obj = createSession();}return obj;}/** * close Session * @param obj * @throws Exception */public void closeSession(RAMSession obj) throws Exception {if(obj!=null) {objectPool.returnObject(obj);printDebugInfo();}}private void printDebugInfo() {if (logger.isDebugEnabled()) {logger.debug("Active number : "+objectPool.getNumActive()+"\t Idle number : "+objectPool.getNumIdle());}}}