休眠保存集合

Question

我使用Hibernate 4（與Spring）將我的對象保存到數據庫中。 我有一些問題，當我嘗試保存收集兒童的父母。

我的表：

| A | => PK (Composite) [String + Integer] 
| B | => PK (Composite) [Stirng + Integer] + Integer 

天然化B的PK是複合材料A的相同pk和含有B.

集合在我的代碼我想：

A parent = new A(); 
parent.addCollection(new B()); 
parentDao.create(parent) 

當Hibernate支持對象時，它可以將一個String設置爲PK，並計算Inter的最大值+1。 對於B PK，同樣的方法，Hibernate從A（parent => child）設置相同的PK值並計算第二個Intenger的max + 1。

有可能嗎？ 在此先感謝

編輯

我的班級：

Class A { 
    static Class A_PK { 
     private String codAzienda; 
     private Integer year; 
     ... Get, Set, HashCode, Equals and toString() ... 
    } 

    private A_PK id; 

    ... another columns ... 

    @OneToMany(cascade=ALL) 
    @JoinColumns({ 
     @JoinColumn(name="cod_azienda"), 
     @JoinColumn(name="year") 
    }) 
    List<B> children; 
} 

Class B { 
    static Class B_PK { 
     private String codAzienda; 
     private Integer year; 
     private Integer nextId; 
     ... Get, Set, HashCode, Equals and toString() ... 
    } 

@EmbeddedId 
@AttributeOverrides({ 
    @AttributeOverride(name = "codAzienda", column = @Column(name = "cod_azienda")), 
    @AttributeOverride(name = "codCliente", column = @Column(name = "cod_cliente")) 
}) 

    private B_PK id; 
    ... another columns ... 
} 

Answer 1

嘗試以下操作：

A.java

@Entity 
@Table(name = "TABLE_A") 
public class A implements Serializable { 

    @Id 
    @Column(name = "STR_ID") 
    private String strId; 

    @Id 
    @Column(name = "INT_ID") 
    @GeneratedValue(strategy = GenerationType.TABLE) 
    private Integer intId; 

    @OneToMany(cascade = CascadeType.ALL, mappedBy = "a") 
    private List<B> bs; 

    public A(String strId) { 
     this.strId = strId; 
    } 

    public void addB(B b) { 
     if (bs == null) { 
      bs = new ArrayList<B>(); 
     } 
     b.setA(this); 
     bs.add(b); 
    } 
} 

B.java

@Entity 
@Table(name = "TABLE_B") 
public class B implements Serializable { 

    @Id 
    @Column(name = "INT_ID") 
    @GeneratedValue(strategy = GenerationType.TABLE) 
    private Integer intId; 

    @Id 
    @ManyToOne 
    @JoinColumns({ 
     @JoinColumn(name = "A_STR_FK", referencedColumnName = "STR_ID"), 
     @JoinColumn(name = "A_INT_FK", referencedColumnName = "INT_ID") 
    }) 
    private A a; 

    void setA(A a) { 
     this.a = a; 
    } 
}