以Locale为键映射的Hibernate注释

Question

我有这些桌子：

CREATE TABLE PRODUCT (
  ID NUMBER(19,0) NOT NULL,
  CONSTRAINT PRODUCT_PK
  PRIMARY KEY (ID)
  USING INDEX (
    CREATE UNIQUE INDEX PRODUCT_PK
    ON PRODUCT(ID)
    ...
  )
)
...

CREATE TABLE PRODUCT_LOCALE (
  PRODUCT_ID NUMBER(19,0) NOT NULL,
  LOCALE VARCHAR2(12 CHAR) NOT NULL,
  NAME VARCHAR2(160 CHAR),
  CONSTRAINT PRODUCT_LOCALE_PK
  PRIMARY KEY (PRODUCT_ID,LOCALE)
)
...

由该类表示：

public class Product extends LocalizedEntity<Product.LocalizedFields> {

  ....

  private Long id;

  public Long getId() {
    return id;
  }

  public void setId(Long id) {
    this.id = id;
  }

  public static class LocalizedFields implements Serializable {

    private String name;

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
  }

}

public abstract class LocalizedEntity<T> implements serializable {

  ....

  private Map<Locale, T> localizedFields = new HashMap<Locale, LF>();

  public Map<Locale, T> getLocalizedFields() {
    return localizedFields;
  }

  public void setLocalizedFields(Map<Locale, T> localizedFields) {
    this.localizedFields = localizedFields;
  }
}

.....
<map name="localizedFields" table="product_locale" lazy="false" fetch="select" batch-size="100">
  <cache usage="read-write" />
  <key column="product_id" not-null="true" />
  <map-key type="locale">
    <column name="locale" length="12" not-null="true" />
  </map-key>
  <composite-element class="com.myproject.Product$LocalizedFields">
    <property name="name" type="string">
        <column name="name" length="500" />
    </property>
  </composite-element>
  </map>
.....

@Entity
@Table(name = "product")
public class Product extends LocalizedEntity<Product.LocalizedFields> {

  ....

  private Long id;

  @Id
  @Column(name = "id")
  @GeneratedValue(strategy= GenerationType.AUTO)
  public Long getId() {
    return id;
  }

  public void setId(Long id) {
    this.id = id;
  }

  @ElementCollection(fetch = FetchType.EAGER)
  @JoinTable(name = "product_locale", joinColumns = @JoinColumn(name = "product_id", nullable = false))
  @MapKeyClass(value = Locale.class)
  @MapKeyColumn(name = "locale", length = 12, nullable = false)
  @BatchSize(size = 100)
  @Fetch(FetchMode.SELECT)
  @Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
  @Embedded
  public Map<Locale, LocalizedFields> getLocalizedFields() {
    return super.getLocalizedFields();
  }

  @Embeddable
  public static class LocalizedFields implements Serializable {

    ....

    private String name;

    @Column(name = "name", length = 500, nullable = false)
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
  }
}

@MappedSuperclass
public abstract class LocalizedEntity<T> implements serializable {

  ....

  private Map<Locale, T> localizedFields = new HashMap<Locale, LF>();

  public Map<Locale, T> getLocalizedFields() {
    return localizedFields;
  }

  public void setLocalizedFields(Map<Locale, T> localizedFields) {
    this.localizedFields = localizedFields;
  }
}

原因：org.hibernate.mappingException：无法确定：java.util.map的类型，位于表：product，列：[org.hibernate.mapping.simplevale.getType(simplevale.java:349)位于org.hibernate.mapping.simplevale.isvalid(simplevale.java:322)位于org.hibernate.mapping.property.isvalid(property.java:241)位于org.hibernate.mapping.persistentclass.validate（ERNATE4.LocalSessionFactoryBean.AfterPropertiesSet（LocalSessionFactoryBean.java:439)位于org.SpringFramework.Beans.Factor.Support.AbstracTautOWIRECAPABLEBeanFactor.InvokeInitMethods（AbstracTautOWIRECAPABLEBeanFactor.1633)位于org.SpringFramework.Beans.Factor.Support.AbstracTautOWIRECAPABLEBeanFactor.InitializeBean（

如果我用@mapkey（“locale”）替换@mapkeyclass（value=locale.class）和@mapkeycolumn,则会引发以下错误：

原因：org.hibernate.AnnotationException：未找到关联类：com.myproject.product$localizedfields在org.hibernate.cfg.Annotations.mapbinder.bindkeyfromAssociationTable（mapbinder.java:133)在org.hibernate.cfg.Annotations.mapbinder.access$000（mapbinder.java:76)在org.hibernate.cfg.Annotations.mapbinder.mapbinder$1。secondpass（mapbinder.java:111)在t org.springframework.orm.hibernate4.localsessionfactorybean.afterpropertiesset(localsessionfactorybean.java:439)在org.springframework.beans.factor.support.abstractautowirecapablebeanfactor.invokeInitMethods(abstractautowirecapablebeanfactor.1633)在

Answer 1

我发现问题是关键的“区域”

根据JPA文档（http://docs.oracle.com/javaee/6/api/index.html?javax/persistence/mapkeyclass.html）：

“为java.util.map类型的关联指定映射键的类型。映射键可以是基本类型、可嵌入类或实体”

有了这些注释，它必须工作：

@ElementCollection(fetch = FetchType.EAGER)
@JoinTable(name = "product_locale", joinColumns = @JoinColumn(name = "product_id", nullable = false))
@MapKeyColumn(name = "locale", length = 12, nullable = false)
@MapKeyType(value = @Type(type = "locale"))
@BatchSize(size = 100)
@Fetch(FetchMode.SELECT)
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)