class expensive{

static stack pool = new stack();

public static expensive getobjectfrompool(){

retun (expensive) pool.pop();

}

public static void shutdownthepool(){

pool = null;

}

public expensive(){

//先構造對象

pool.push(this)；

}

finalize (){

if(pool!=null){

gc.registerforfinally(this;)//先把他叫醒挨宰

pool.push(this);//將“清醒的”對象加入到對象池中,讓他起死回生

}

}

}

class app{

static void main(){

new expensive();

……

expensive e = expensiv. getobjectfrompool();

//下面就可以使用e了

expensive.shutdownthepool();//關閉應用程序前，先關閉對象池，否則會在內存中留下“孔洞”，因為finalize已經被重寫了

}

}