Copyright (c) 2008 - 2015 Oracle Corporation. All rights reserved.
This program and the accompanying materials are made available under the
terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
which accompanies this distribution.
The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
and the Eclipse Distribution License is available at
http://www.eclipse.org/org/documents/edl-v10.php.
Contributors:
Petros Splinakis - Java Persistence 2.2
Linda DeMichiel - Java Persistence 2.1
Linda DeMichiel - Java Persistence 2.0
/*******************************************************************************
* Copyright (c) 2008 - 2015 Oracle Corporation. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0
* which accompanies this distribution.
* The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Petros Splinakis - Java Persistence 2.2
* Linda DeMichiel - Java Persistence 2.1
* Linda DeMichiel - Java Persistence 2.0
*
******************************************************************************/
package javax.persistence;
import java.lang.annotation.Repeatable;
import java.lang.annotation.Target;
import java.lang.annotation.Retention;
import static java.lang.annotation.ElementType.TYPE;
import static java.lang.annotation.ElementType.METHOD;
import static java.lang.annotation.ElementType.FIELD;
import static java.lang.annotation.RetentionPolicy.RUNTIME;
Used to override the mapping of a Basic (whether
explicit or default) property or field or Id property or
field.
May be applied to an entity that extends a mapped superclass or
to an embedded field or property to override a basic mapping or id
mapping defined by the mapped superclass or embeddable class (or
embeddable class of one of its attributes).
May be applied to an element collection containing instances of
an embeddable class or to a map collection whose key and/or value
is an embeddable class. When AttributeOverride is
applied to a map, "key." or "value." must
be used to prefix the name of the attribute that is being
overridden in order to specify it as part of the map key or map
value.
To override mappings at multiple levels of embedding, a dot (".")
notation form must be used in the name element to indicate an
attribute within an embedded attribute. The value of each identifier
used with the dot notation is the name of the respective embedded
field or property.
If AttributeOverride is not specified, the column
is mapped the same as in the original mapping.
Example 1:
@MappedSuperclass
public class Employee {
@Id protected Integer id;
@Version protected Integer version;
protected String address;
public Integer getId() { ... }
public void setId(Integer id) { ... }
public String getAddress() { ... }
public void setAddress(String address) { ... }
}
@Entity
@AttributeOverride(name="address", column=@Column(name="ADDR"))
public class PartTimeEmployee extends Employee {
// address field mapping overridden to ADDR
protected Float wage();
public Float getHourlyWage() { ... }
public void setHourlyWage(Float wage) { ... }
}
Example 2:
@Embeddable public class Address {
protected String street;
protected String city;
protected String state;
@Embedded protected Zipcode zipcode;
}
@Embeddable public class Zipcode {
protected String zip;
protected String plusFour;
}
@Entity public class Customer {
@Id protected Integer id;
protected String name;
@AttributeOverrides({
@AttributeOverride(name="state",
column=@Column(name="ADDR_STATE")),
@AttributeOverride(name="zipcode.zip",
column=@Column(name="ADDR_ZIP"))
})
@Embedded protected Address address;
...
}
Example 3:
@Entity public class PropertyRecord {
@EmbeddedId PropertyOwner owner;
@AttributeOverrides({
@AttributeOverride(name="key.street",
column=@Column(name="STREET_NAME")),
@AttributeOverride(name="value.size",
column=@Column(name="SQUARE_FEET")),
@AttributeOverride(name="value.tax",
column=@Column(name="ASSESSMENT"))
})
@ElementCollection
Map<Address, PropertyInfo> parcels;
}
@Embeddable public class PropertyInfo {
Integer parcelNumber;
Integer size;
BigDecimal tax;
}
See Also: Since: Java Persistence 1.0
/**
* Used to override the mapping of a <code>Basic</code> (whether
* explicit or default) property or field or <code>Id</code> property or
* field.
*
* <p> May be applied to an entity that extends a mapped superclass or
* to an embedded field or property to override a basic mapping or id
* mapping defined by the mapped superclass or embeddable class (or
* embeddable class of one of its attributes).
* <p> May be applied to an element collection containing instances of
* an embeddable class or to a map collection whose key and/or value
* is an embeddable class. When <code>AttributeOverride</code> is
* applied to a map, "<code>key.</code>" or "<code>value.</code>" must
* be used to prefix the name of the attribute that is being
* overridden in order to specify it as part of the map key or map
* value.
*
* <p> To override mappings at multiple levels of embedding, a dot (".")
* notation form must be used in the <code>name</code> element to indicate an
* attribute within an embedded attribute. The value of each identifier
* used with the dot notation is the name of the respective embedded
* field or property.
*
* <p> If <code>AttributeOverride</code> is not specified, the column
* is mapped the same as in the original mapping.
*
* <pre>
* Example 1:
*
* @MappedSuperclass
* public class Employee {
* @Id protected Integer id;
* @Version protected Integer version;
* protected String address;
* public Integer getId() { ... }
* public void setId(Integer id) { ... }
* public String getAddress() { ... }
* public void setAddress(String address) { ... }
* }
*
* @Entity
* @AttributeOverride(name="address", column=@Column(name="ADDR"))
* public class PartTimeEmployee extends Employee {
* // address field mapping overridden to ADDR
* protected Float wage();
* public Float getHourlyWage() { ... }
* public void setHourlyWage(Float wage) { ... }
* }
*
*
* Example 2:
*
* @Embeddable public class Address {
* protected String street;
* protected String city;
* protected String state;
* @Embedded protected Zipcode zipcode;
* }
*
* @Embeddable public class Zipcode {
* protected String zip;
* protected String plusFour;
* }
*
* @Entity public class Customer {
* @Id protected Integer id;
* protected String name;
* @AttributeOverrides({
* @AttributeOverride(name="state",
* column=@Column(name="ADDR_STATE")),
* @AttributeOverride(name="zipcode.zip",
* column=@Column(name="ADDR_ZIP"))
* })
* @Embedded protected Address address;
* ...
* }
*
*
* Example 3:
*
* @Entity public class PropertyRecord {
* @EmbeddedId PropertyOwner owner;
* @AttributeOverrides({
* @AttributeOverride(name="key.street",
* column=@Column(name="STREET_NAME")),
* @AttributeOverride(name="value.size",
* column=@Column(name="SQUARE_FEET")),
* @AttributeOverride(name="value.tax",
* column=@Column(name="ASSESSMENT"))
* })
* @ElementCollection
* Map<Address, PropertyInfo> parcels;
* }
*
* @Embeddable public class PropertyInfo {
* Integer parcelNumber;
* Integer size;
* BigDecimal tax;
* }
*
* </pre>
*
* @see Embedded
* @see Embeddable
* @see MappedSuperclass
* @see AssociationOverride
*
* @since Java Persistence 1.0
*/
@Repeatable(AttributeOverrides.class)
@Target({TYPE, METHOD, FIELD})
@Retention(RUNTIME)
public @interface AttributeOverride {
(Required) The name of the property whose mapping is being
overridden if property-based access is being used, or the
name of the field if field-based access is used.
/**
* (Required) The name of the property whose mapping is being
* overridden if property-based access is being used, or the
* name of the field if field-based access is used.
*/
String name();
(Required) The column that is being mapped to the persistent
attribute. The mapping type will remain the same as is
defined in the embeddable class or mapped superclass.
/**
* (Required) The column that is being mapped to the persistent
* attribute. The mapping type will remain the same as is
* defined in the embeddable class or mapped superclass.
*/
Column column();
}