//從池中獲取對(duì)象
T borrowObject() throws Exception, NoSuchElementException,IllegalStateException;
//將對(duì)象放回池中
void returnObject(T obj) throws Exception;
//廢棄對(duì)象
void invalidateObject(T obj) throws Exception;
//添加對(duì)象
void addObject() throws Exception, IllegalStateException,UnsupportedOperationException;
//獲取對(duì)象個(gè)數(shù)
int getNumIdle();
//獲取活躍對(duì)象個(gè)數(shù)
int getNumActive();
//清除池，池可用
void clear() throws Exception, UnsupportedOperationException;
//關(guān)閉池，池不可用
void close();

//創(chuàng)建一個(gè)新對(duì)象;當(dāng)對(duì)象池中的對(duì)象個(gè)數(shù)不足時(shí),將會(huì)使用此方法來"輸出"一個(gè)新的"對(duì)象",并交付給對(duì)象池管理
PooledObject<T> makeObject() throws Exception;
//銷毀對(duì)象,如果對(duì)象池中檢測到某個(gè)"對(duì)象"idle的時(shí)間超時(shí),或者操作者向?qū)ο蟪?歸還對(duì)象"時(shí)檢測到"對(duì)象"已經(jīng)無效,那么此時(shí)將會(huì)導(dǎo)致"對(duì)象銷毀";"銷毀對(duì)象"的操作設(shè)計(jì)相差甚遠(yuǎn),但是必須明確:當(dāng)調(diào)用此方法時(shí),"對(duì)象"的生命周期必須結(jié)束.如果object是線程,那么此時(shí)線程必須退出;如果object是socket操作,那么此時(shí)socket必須關(guān)閉;如果object是文件流操作,那么此時(shí)"數(shù)據(jù)flush"且正常關(guān)閉.
void destroyObject(PooledObject<T> p) throws Exception;
//檢測對(duì)象是否"有效";Pool中不能保存無效的"對(duì)象",因此"后臺(tái)檢測線程"會(huì)周期性的檢測Pool中"對(duì)象"的有效性,如果對(duì)象無效則會(huì)導(dǎo)致此對(duì)象從Pool中移除,并destroy;此外在調(diào)用者從Pool獲取一個(gè)"對(duì)象"時(shí),也會(huì)檢測"對(duì)象"的有效性,確保不能講"無效"的對(duì)象輸出給調(diào)用者;當(dāng)調(diào)用者使用完畢將"對(duì)象歸還"到Pool時(shí),仍然會(huì)檢測對(duì)象的有效性.所謂有效性,就是此"對(duì)象"的狀態(tài)是否符合預(yù)期,是否可以對(duì)調(diào)用者直接使用;如果對(duì)象是Socket,那么它的有效性就是socket的通道是否暢通/阻塞是否超時(shí)等.
boolean validateObject(PooledObject<T> p);
// "激活"對(duì)象,當(dāng)Pool中決定移除一個(gè)對(duì)象交付給調(diào)用者時(shí)額外的"激活"操作,比如可以在activateObject方法中"重置"參數(shù)列表讓調(diào)用者使用時(shí)感覺像一個(gè)"新創(chuàng)建"的對(duì)象一樣;如果object是一個(gè)線程,可以在"激活"操作中重置"線程中斷標(biāo)記",或者讓線程從阻塞中喚醒等;如果object是一個(gè)socket,那么可以在"激活操作"中刷新通道,或者對(duì)socket進(jìn)行鏈接重建(假如socket意外關(guān)閉)等.
void activateObject(PooledObject<T> p) throws Exception;
//"鈍化"對(duì)象,當(dāng)調(diào)用者"歸還對(duì)象"時(shí),Pool將會(huì)"鈍化對(duì)象";鈍化的言外之意,就是此"對(duì)象"暫且需要"休息"一下.如果object是一個(gè)socket,那么可以passivateObject中清除buffer,將socket阻塞;如果object是一個(gè)線程,可以在"鈍化"操作中將線程sleep或者將線程中的某個(gè)對(duì)象wait.需要注意的時(shí),activateObject和passivateObject兩個(gè)方法需要對(duì)應(yīng),避免死鎖或者"對(duì)象"狀態(tài)的混亂.
void passivateObject(PooledObject<T> p) throws Exception;

T getObject();
long getCreateTime();
long getActiveTimeMillis();
long getIdleTimeMillis();
long getLastBorrowTime();
long getLastReturnTime();
long getLastUsedTime();
int compareTo(PooledObject<T> other);
boolean equals(Object obj);
int hashCode();
String toString();
//后臺(tái)清理線程
boolean startEvictionTest();
boolean endEvictionTest(Deque<PooledObject<T>> idleQueue);
boolean allocate();
boolean deallocate();
void invalidate()
void setLogAbandoned(boolean logAbandoned);
void use();
void printStackTrace(PrintWriter writer);
PooledObjectState getState();
//自動(dòng)補(bǔ)償功能
void markAbandoned();
void markReturning();