这些选项包括：可选值的缺省值、要在数据编组对象前或数据编出对象后调用的方法，以及用于引用对象的标识值。

These include defaults for optional values, methods to be called before marshalling or after unmarshalling objects, and identifier values for referencing objects.

youdao

要数据编组的对象必须是类的一个实例，该类是用绑定中的全局映射定义的。

The object to be marshalled must be an instance of a class that's defined with a global mapping in the binding.

youdao

然后必须将数据库内容读取到对象模型中，并请求底层框架将其内部的结构编组为xml格式。

You would then have to read the contents of the database into your object model and then request the underlying framework to Marshall its internal structure to an XML format.

youdao