PHP序列化对象树

Question

我有一个如下所示的对象树，我需要对其进行序列化并存储在文件系统中。我需要具有所有类属性的完整层次结构，稍后我将反序列化并恢复类层次结构。

class X implements \Serializable {

  private $x1;

    public function serialize() {
            return serialize(get_class_vars(get_class($this)));
    }

    public function unserialize($data) {
            $values = unserialize($data);
            foreach ($values as $key => $value) {
                    $this->$key = $value;
            }
    }
}

class A implements \Serializable {

  private $a1;
  private $a2;
  // type of a3 is class X!
  protected $a3;

    public function serialize() {
            return serialize(get_class_vars(get_class($this)));
    }

    public function unserialize($data) {
            $values = unserialize($data);
            foreach ($values as $key => $value) {
                    $this->$key = $value;
            }
    }
}

class B extends A implements \Serializable {

  private $b1;
  private $b2;

    public function serialize() {
    //  $base = parent::serialize();
            return serialize(get_class_vars(get_class($this)));
    }

    public function unserialize($data) {
            $values = unserialize($data);
            foreach ($values as $key => $value) {
                    $this->$key = $value;
            }
    }
}


class C extends A implements \Serializable {

  private $c1;
  private $c2;

    public function serialize() {
    //  $base = parent::serialize();
            return serialize(get_class_vars(get_class($this)));
    }

    public function unserialize($data) {
            $values = unserialize($data);
            foreach ($values as $key => $value) {
                    $this->$key = $value;
            }
    }
}

子类可以自己序列化，但是对于基类我不知道如何组合序列化的数据。此外，我从文件系统获取序列化数据，但我不知道我会得到哪个子类。 PHP 的 unserialize() 是否创建了正确的类实例？它还应该初始化基类 A。

我该如何解决？

也许我可以使用 var_dump() 输出，但如何将其存储到变量中？

Answer 1

这就是我推荐的序列化对象的方式：

class Color implements \Serializable
{
    private $Name;
    private $Type;

    public function __construct(string $Name, int $Type)
    {
        $this->Name = $Name;
        $this->Type = $Type;
    }

    public function serialize()
    {
        $Props['Name'] = $this->Name;
        $Props['Type'] = $this->Type;
        return serialize($Props);
    }

    public function unserialize($Data)
    {
        list($this->Name, $this->Type) = unserialize($Data);
    }
}

class Blue extends Color
{
    private $Intensity;

    public function __construct()
    {
        parent::__construct('Blue', 10);
        $this->Intensity = 90;
    }

    public function serialize()
    {
        $Props['parent'] = parent::serialize();
        $Props['Intensity'] = $this->Intensity;
        return serialize($Props);
    }

    public function unserialize($Data)
    {
        $Obj = unserialize($Data);
        parent::unserialize($Obj['parent']);
        $this->Intensity = $Obj['Intensity'];
    }
}

您传递给 serialize() 函数的任何对象都是您将返回（作为字符串）到 unserialize() 的对象。如果你走自己的路，那么你可以在 trait 中实现 serialize()/unserialize() 函数，而 get_object_vars() 将适用于私有变量。

Answer 2

我已经在每个受影响的类中实现了 serialize() 和 unserialize()，如下所示：

        public function serialize() {

            $res = array();

            $reflect = new \ReflectionClass(__CLASS__);
            $propList = $reflect->getProperties();

            foreach($propList as $prop) {
                    if ($prop->class != __CLASS__) {
                            continue; // visible properties of base clases
                    }

                    $name = $prop->name;
                    $res[$name . ":" . __CLASS__] = serialize($this->$name);
            }

            if (method_exists(get_parent_class(__CLASS__), "serialize")) {
                    $base = unserialize(parent::serialize());
                    $res = array_merge($res, $base);
            }

            return serialize($res);
    }

    public function unserialize($data) {

            $values = unserialize($data);
            foreach ($values as $key => $value) {

                    // key contains propertyName:className
                    $prop = explode(":", $key);
                    if ($prop[1] != __CLASS__) {
                            continue;
                    }

                    $this->$prop[0] = unserialize($value);
            }

            // call base class
            if (method_exists(get_parent_class(__CLASS__), "unserialize")) {
                    parent::unserialize($data);
            }
    }

也许有一种解决方案可以将此功能添加到基类以防止代码复制。它应该适用于简单的属性、数组和对象，也适用于具有多级父类的大型对象树。