Parent key of type encoded string?

How do we create a parent key which is an encoded string? Example:

class Parent {

    @PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
    @Extension(vendorName="datanucleus", key="gae.encoded-pk", value="true")
    private String mEncKey;
}

class Child {

    @PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
    @Extension(vendorName="datanucleus", key="gae.encoded-pk", value="true")
    private String mEncKey;

    // In the doc examples, they have Key as the type here.
    @Persistent
    @Extension(vendorName="datanucleus", key="gae.parent-pk", value="true")
    private String mParentEncKey;
}

yeah I'm not sure how to make mParentEncKey an encoded string type, because the 'key' label is already being used? I would need something like?:

key="gae.parent-pk.encoded-pk"

not sur开发者_开发问答e - is that possible?

Thanks

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I have found a solution for this, you can now map owned relations in a portable manner, check out blog.

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This discussion says to just use gae.parent-pk - GAE will automatically use an encoded string value for a parent key field in Child.

https://groups.google.com/group/google-appengine-java/browse_thread/thread/43e38d0bc8a41bbd/0f0f86693330c1b2