org.hibernate.usertype

Interface CompositeUserType

public interface CompositeUserType

A UserType that may be dereferenced in a query. This interface allows a custom type to define "properties". These need not necessarily correspond to physical JavaBeans style properties.

A CompositeUserType may be used in almost every way that a component may be used. It may even contain many-to-one associations.

Implementors must be immutable and must declare a public default constructor.

Unlike UserType, cacheability does not depend upon serializability. Instead, assemble() and disassemble provide conversion to/from a cacheable representation.

Author:

Gavin King

See Also:

for more simple cases, Type

Method Summary

Methods

Modifier and Type	Method and Description
Object	assemble(Serializable cached, SessionImplementor session, Object owner) Reconstruct an object from the cacheable representation.
Object	deepCopy(Object value) Return a deep copy of the persistent state, stopping at entities and at collections.
Serializable	disassemble(Object value, SessionImplementor session) Transform the object into its cacheable representation.
boolean	equals(Object x, Object y) Compare two instances of the class mapped by this type for persistence "equality".
String[]	getPropertyNames() Get the "property names" that may be used in a query.
Type[]	getPropertyTypes() Get the corresponding "property types".
Object	getPropertyValue(Object component, int property) Get the value of a property.
int	hashCode(Object x) Get a hashcode for the instance, consistent with persistence "equality"
boolean	isMutable() Check if objects of this type mutable.
Object	nullSafeGet(ResultSet rs, String[] names, SessionImplementor session, Object owner) Retrieve an instance of the mapped class from a JDBC resultset.
void	nullSafeSet(PreparedStatement st, Object value, int index, SessionImplementor session) Write an instance of the mapped class to a prepared statement.
Object	replace(Object original, Object target, SessionImplementor session, Object owner) During merge, replace the existing (target) value in the entity we are merging to with a new (original) value from the detached entity we are merging.
Class	returnedClass() The class returned by nullSafeGet().
void	setPropertyValue(Object component, int property, Object value) Set the value of a property.

Method Detail

getPropertyNames

String[] getPropertyNames()

Get the "property names" that may be used in a query.

Returns:

an array of "property names"

getPropertyTypes

Type[] getPropertyTypes()

Get the corresponding "property types".

Returns:

an array of Hibernate types

getPropertyValue

Object getPropertyValue(Object component,
                      int property)
                        throws HibernateException

Get the value of a property.

Parameters:

component - an instance of class mapped by this "type"

property -

Returns:

the property value

Throws:

HibernateException

setPropertyValue

void setPropertyValue(Object component,
                    int property,
                    Object value)
                      throws HibernateException

Set the value of a property.

Parameters:

component - an instance of class mapped by this "type"

property -

value - the value to set

Throws:

HibernateException

returnedClass

Class returnedClass()

The class returned by nullSafeGet().

Returns:

Class

equals

boolean equals(Object x,
             Object y)
               throws HibernateException

Compare two instances of the class mapped by this type for persistence "equality". Equality of the persistent state.

Throws:

HibernateException

hashCode

int hashCode(Object x)
             throws HibernateException

Get a hashcode for the instance, consistent with persistence "equality"

Throws:

HibernateException

nullSafeGet

Object nullSafeGet(ResultSet rs,
                 String[] names,
                 SessionImplementor session,
                 Object owner)
                   throws HibernateException,
                          SQLException

Retrieve an instance of the mapped class from a JDBC resultset. Implementors should handle possibility of null values.

Parameters:

rs - a JDBC result set

names - the column names

session -

owner - the containing entity

Returns:

Object

Throws:

HibernateException

SQLException

nullSafeSet

void nullSafeSet(PreparedStatement st,
               Object value,
               int index,
               SessionImplementor session)
                 throws HibernateException,
                        SQLException

Write an instance of the mapped class to a prepared statement. Implementors should handle possibility of null values. A multi-column type should be written to parameters starting from index.

Parameters:

st - a JDBC prepared statement

value - the object to write

index - statement parameter index

session -

Throws:

HibernateException

SQLException

deepCopy

Object deepCopy(Object value)
                throws HibernateException

Return a deep copy of the persistent state, stopping at entities and at collections.

Parameters:

value - generally a collection element or entity field

Returns:

Object a copy

Throws:

HibernateException

isMutable

boolean isMutable()

Check if objects of this type mutable.

Returns:

boolean

disassemble

Serializable disassemble(Object value,
                       SessionImplementor session)
                         throws HibernateException

Transform the object into its cacheable representation. At the very least this method should perform a deep copy. That may not be enough for some implementations, however; for example, associations must be cached as identifier values. (optional operation)

Parameters:

value - the object to be cached

session -

Returns:

a cachable representation of the object

Throws:

HibernateException

assemble

Object assemble(Serializable cached,
              SessionImplementor session,
              Object owner)
                throws HibernateException

Reconstruct an object from the cacheable representation. At the very least this method should perform a deep copy. (optional operation)

Parameters:

cached - the object to be cached

session -

owner - the owner of the cached object

Returns:

a reconstructed object from the cachable representation

Throws:

HibernateException

replace

Object replace(Object original,
             Object target,
             SessionImplementor session,
             Object owner)
               throws HibernateException

During merge, replace the existing (target) value in the entity we are merging to with a new (original) value from the detached entity we are merging. For immutable objects, or null values, it is safe to simply return the first parameter. For mutable objects, it is safe to return a copy of the first parameter. However, since composite user types often define component values, it might make sense to recursively replace component values in the target object.

Throws:

HibernateException