namespace woo/domain;//標識映射class ObjectWatcher{    private $all = array();        //存放對象的小倉庫  private $dirty = array();      //存放需要在數據庫中修改的對象  private $new = array();        //存放需要在數據庫中新增的對象  private $delete = array();      //存放需要在數據庫中刪除的對象  private static $instance;      //單例      private function __construct (){}    static function instance(){    if(!self::$instance){      self::$instance = new ObjectWatcher();    }    return self::$instance;  }    //獲取一個唯一的標識,這里采用了領域類類名+ID的方式創建一個唯一標識，避免多個數據庫表調用這個類時出現ID重復的問題  function globalKey(DomainObject $obj){    $key = get_class($obj) . "." . $obj->getId();    return $key;  }    //添加對象  static function add(DomainObject $obj){    $inst = self::instance();    $inst->all[$inst->globalKey($obj)] = $obj;  }    //獲取對象  static function exists($classname,$id){    $inst = self::instance();    $key = "$classname.$id";    if(isset($inst->all[$key]){      return $inst->all[$key];    }    return null;  }    //標記為需要刪除的對象  static function addDelete(DomainObject $obj){    $self = self::instance();    $self->delete[$self->globalKey($obj)] = $obj;  }    //標記為需要修改的對象  static function addDirty(DomainObject $obj){    $inst = self::instance();    if(!in_array($obj,$inst->new,true)){      $inst->dirty[$inst->globalKey($obj)] = $obj;    }  }    //標記為需要新增的對象  static function addNew(DomainObject $obj){    $inst = self::instance();    $inst->new[] = $obj;  }    //標記為干凈的對象  static function addClean(DomainObject $obj){    $self = self::instance();    unset($self->delete[$self->globalKey($obj)]);    unset($self->dirty[$self->globalKey($obj)]);    $self->new = array_filter($self->new,function($a) use($obj) {return !($a === $obj);});  }      //將上述需要增刪改的對象與數據庫交互進行處理    function performOperations(){    foreach($this->dirty as $key=>$obj){      $obj->finder()->update($obj);    //$obj->finder()獲取一個數據映射器    }    foreach($this->new as $key=>$obj){      $obj->finder()->insert($obj);    }    $this->dirty = array();    $this->new = array();  }}//領域模型abstract class DomainObject{      //抽象基類    private $id = -1;    function __construct ($id=null){    if(is_null($id)){      $this->markNew();      //初始化時即被標記為需要新增的對象了    } else {      $this->id = $id;    }    }    //調用了標識映射的標記對象的方法  function markNew(){    ObjectWatcher::addNew($this);  }    function markDeleted(){    ObjectWatcher::addDelete($this);  }    function markDirty(){    ObjectWatcher::addDirty($this);  }    function markClean(){    ObjectWatcher::addClean($this);  }    function setId($id){    $this->id = $id;  }    function getId(){    return $this->id;  }      function finder(){    return self::getFinder(get_class($this));  }    //通過工廠類來實例化一個特定類型的數據映射器對象，例如VenueMapper  //這個對象將被標識映射器中的performOperations方法調用用于與數據庫交互進行增刪改的操作  static function getFinder($type){    return HelperFactory::getFinder($type);  }  }class Venue extends DomainObject {  private $name;  private $spaces;    function __construct ($id = null,$name=null){    $this->name= $name;    $this->spaces = self::getCollection('//woo//domain//space');     parent::__construct($id);  }    function setSpaces(SpaceCollection $spaces){    $this->spaces = $spaces;    $this->markDirty();            //標記為需要修改的對象  }    function addSpace(Space $space){    $this->spaces->add($space);    $space->setVenue($this);    $this->markDirty();            //標記為需要修改的對象  }    function setName($name_s){    $this->name = $name_s;    $this->markDirty();            //標記為需要修改的對象  }    function getName(){    return $this->name;  }}//領域模型class Space extends DomainObject{  //.........  function setName($name_s){    $this->name = $name_s;    $this->markDirty();  }    function setVenue(Venue $venue){    $this->venue = $venue;    $this->markDirty();  }}//數據映射器abstract class Mapper{    abstract static $PDO;    //操作數據庫的pdo對象  function __construct (){    if(!isset(self::$PDO){      $dsn = /woo/base/ApplicationRegistry::getDSN();      if(is_null($dsn)){        throw new /woo/base/AppException("no dns");      }      self::$PDO = new /PDO($dsn);      self::$PDO->setAttribute(/PDO::ATTR_ERRMODE,/PDO::ERRMODE_EXCEPTION);    }  }    //獲取標記的對象  private function getFroMap($id){    return /woo/domain/ObjectWatcher::exists($this->targetClass(),$id);  }      //新增標記的對象  private function addToMap(/woo/domain/DomainObject $obj){//////    return /woo/domain/ObjectWatcher::add($obj);  }      //將數據庫數據映射為對象  function createObject($array){    $old = $this->getFromMap($array['id']);    if($old){return $old;}    $obj = $this->doCreateObject($array);    $this->addToMap($obj);    $obj->markClean();    return $obj;  }    function find($id){                //通過ID從數據庫中獲取一條數據并創建為對象      $old = $this->getFromMap($id);            if($old){return $old}                    $this->selectStmt()->execute(array($id));    $array= $this->selectStmt()->fetch();    $this->selectStmt()->closeCursor();    if(!is_array($array)){      return null;    }    if(!isset($array['id'])){      return null;    }    $object = $this->createObject($array);    $this->addToMap($object);              return $object;    }      function insert(/woo/domain/DomainObject $obj){      //將對象數據插入數據庫    $this->doInsert($obj);    $this->addToMap($obj);              }    //需要在子類中實現的各個抽象方法  abstract function targetClass();                    //獲取類的類型  abstract function update(/woo/domain/DomainObject $objet);        //修改操作  protected abstract function doCreateObject(array $array);        //創建對象  protected abstract function selectStmt();                //查詢操作  protected abstract function doInsert(/woo/domain/DomainObject $object);  //插入操作  }class VenueMapper extends Mapper {  function __construct (){        parent::__construct();      //預處理對象    $this->selectStmt = self::$PDO->prepare("select * from venue where id=?");    $this->updateStmt = self::$PDO->prepare("update venue set name=?,id=? where id=?");    $this->insertStmt = self::$PDO->prepare("insert into venue (name) values(?)");  }    protected function getCollection(array $raw){    //將Space數組轉換成對象集合    return new SpaceCollection($raw,$this);          }    protected function doCreateObject (array $array){  //創建對象    $obj = new /woo/domain/Venue($array['id']);    $obj->setname($array['name']);    return $obj;  }    protected function doInsert(/woo/domain/DomainObject $object){ //將對象插入數據庫    print 'inserting';    debug_print_backtrace();    $values = array($object->getName());    $this->insertStmt->execute($values);    $id = self::$PDO->lastInsertId();    $object->setId($id);  }    function update(/woo/domain/DomainObject $object){    //修改數據庫數據    print "updation/n";    $values = array($object->getName(),$object->getId(),$object->getId());    $this->updateStmt->execute($values);  }    function selectStmt(){          //返回一個預處理對象    return $this->selectStmt;  }  }//客戶端$venue = new /woo/domain/Venue(null,"The Green Tree");        //在初始化時就被標記為新增對象了$venue->addSpace(new /woo/domain/Space(null,"The Space Upstairs"));  //這二行addSpace方法因為venue已經被標記新增所以不會再標記為修改對象,但是space在初始化的時候會被標記為新增對象$venue->addSpace(new /woo/domain/Space(null,"The Bar Stage"));　　　　　　/woo/domain/ObjectWatcher::instance()->performOperations();      //與數據庫交互新增一條Venue數據,以及二條space數據