如何使用具有多列/复合主键的表(jpa 1.0@idclass)实现继承?

给出下表:

CREATE TABLE Employees
(
  first_name VARCHAR(50) NOT NULL,
  last_name VARCHAR(50) NOT NULL,
  birth_date DATE NOT NULL,
  PRIMARY KEY (first_name, last_name)
);

CREATE TABLE Managers
(
  first_name VARCHAR(50) NOT NULL,
  last_name VARCHAR(50) NOT NULL,
  salary INTEGER NOT NULL,
  total_bonus INTEGER NULL,
  PRIMARY KEY (first_name, last_name),
  CONSTRAINT managers_employees_fk FOREIGN KEY (first_name, last_name) REFERENCES Employees (first_name, last_name)
);

CREATE TABLE Workers
(
  first_name VARCHAR(50) NOT NULL,
  last_name VARCHAR(50) NOT NULL,
  wage INTEGER NOT NULL,
  PRIMARY KEY (first_name, last_name),
  CONSTRAINT workers_employees_fk FOREIGN KEY (first_name, last_name) REFERENCES Employees (first_name, last_name)
);

如何使用jpa 1.0@idclass注释实现实体和复合主键类?

出现的子问题有:

1. 子类是否定义自己的ID类?
2. 如果是,它们是否继承自超级类的ID类?
3. 子类是否获得@idclass注释?

注意这个问题是故意天真的。我想看看类声明、带有字段访问注释的属性(不带getter和setter)可能就足够了。

谢谢