How can I map a column of Json Array into a list or map of non-pk column mapping?

I have two tables.

-- child
id           key (VARCHAR, UNIQUE)
----------------------------------
0            'a'
1            'b'

-- parent
id           child_keys (JSON)
------------------------------
0            ["a", "b"]

Ho can I map the child_keys column into a List or Map of Child?

class Parent {

    // works
    @JdbcTypeCode(SqlTypes.JSON)
    @Column(name = "child_keys")
    List<String> childKeys;

    // how can I do this?
    // Child(0,"a"), Child(1,"b")
    List<Child> children;

    // or this?
    // "a"-Child(0,"a"), "b"-Child(1, "b")
    Map<String, Child> children;
}