ch.agent.crnickl.api

Interface Surrogate

All Known Implementing Classes:

SurrogateImpl

public interface Surrogate

A Surrogate represents a database object.

Author:

Jean-Paul Vetterli

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object o)
Database	getDatabase() Return the database of the database object.
DBObjectType	getDBObjectType() Return a keyword identifying the type of database object of this surrogate.
DBObjectId	getId() Return the id of this database object.
DBObject	getObject() Returns the database object corresponding to the surrogate.
int	hashCode() Return the hashCode of this surrogate unless it is in construction.
boolean	inConstruction() Test whether the data object is in the database or is a new object being constructed.
String	toString() Applications can rely on this method when needing to display the surrogate in a user interface or in a report.
void	upgrade(Surrogate surrogate) Leave the in construction state and take the identity of the parameter.

Method Detail

toString

String toString()

Applications can rely on this method when needing to display the surrogate in a user interface or in a report.

Overrides:

toString in class Object

Returns:

a readable and useful representation of the surrogate

inConstruction

boolean inConstruction()

Test whether the data object is in the database or is a new object being constructed.

Returns:

true if the database object is in construction

upgrade

void upgrade(Surrogate surrogate)

Leave the in construction state and take the identity of the parameter. This is the only modification which can be made to a surrogate. It is illegal to use this method on a surrogate not in construction and it is illegal to pass an incompatible surrogate or a surrogate in construction.

Parameters:

surrogate - a surrogate which will transmit its identity to this surrogate

getObject

DBObject getObject()

Returns the database object corresponding to the surrogate. If the object cannot be found (for example because it was deleted), the method return an invalid database object. If the surrogate is in construction, the method returns null.

Returns:

the database object or null

getId

DBObjectId getId()

Return the id of this database object. The id can be null, meaning the object is in construction.

Returns:

a DBObjectId or null

getDatabase

Database getDatabase()

Return the database of the database object.

Returns:

a database

getDBObjectType

DBObjectType getDBObjectType()

Return a keyword identifying the type of database object of this surrogate.

Returns:

a constant value identifying the database object type

equals

boolean equals(Object o)

Clients can rely on this method to return true when the underlying database objects are the same. The method returns false when inConstruction() is true for one of the objects involved.

Overrides:

equals in class Object

Returns:

true if this surrogate corresponds to the same database object as the argument's

hashCode

int hashCode()

Return the hashCode of this surrogate unless it is in construction. When inConstruction() is true throw an IllegalStateException.

Overrides:

hashCode in class Object

Returns:

the hashCode of this surrogate