## 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.

See Also:
  `for more simple cases`, `Type`

Method Summary
`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`

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