Hibernate @IdClass @EmbeddedID相关注解

Hibernate Annotations 

Mapping composite primary keys and foreign keys to composite primary keys： 

http://docs.jboss.org/hibernate/annotations/3.5/reference/en/html_single/#d0e2177

引用Composite primary keys use a embedded class as the primary key representation, so you‘d use the @Id and @Embeddable annotations. Alternatively, you can use the @EmbeddedId annotation. Note that the dependent class has to be serializable and implements equals()/hashCode(). You can also use @IdClass.

@Entity
public class RegionalArticle implements Serializable {

    @Id
    public RegionalArticlePk getPk() { ... }
}

@Embeddable
public class RegionalArticlePk implements Serializable { ... }       

@Entity
public class RegionalArticle implements Serializable {

    @EmbeddedId
    public RegionalArticlePk getPk() { ... }
}

public class RegionalArticlePk implements Serializable { ... }

Hibernate @IdClass @EmbeddedID相关注解

原文：http://blog.csdn.net/love_xsq/article/details/41981511