org.castor.cpa.persistence.sql.keygen
Class MaxKeyGenerator

java.lang.Object
  org.castor.cpa.persistence.sql.keygen.AbstractKeyGenerator
      org.castor.cpa.persistence.sql.keygen.AbstractBeforeKeyGenerator
          org.castor.cpa.persistence.sql.keygen.MaxKeyGenerator

All Implemented Interfaces:

KeyGenerator

public final class MaxKeyGenerator
extends AbstractBeforeKeyGenerator

MAX key generators.

Version:

$Revision$ $Date: 2006-04-25 15:08:23 -0600 (Tue, 25 Apr 2006) $

Author:

Oleg Nitz, Leonardo Souza Mario Bueno, Bruce Snyder, Ralf Joachim

See Also:

MaxKeyGeneratorFactory

Constructor Summary

MaxKeyGenerator(PersistenceFactory factory, int sqlType)
Initialize the MAX key generator.

Method Summary

java.lang.Object	generateKey(java.sql.Connection conn, java.lang.String tableName, java.lang.String primKeyName) Generate a new key for the specified table as "MAX(primary_key) + 1".
boolean	isInSameConnection() Is key generated in the same connection as INSERT? For DURING_INSERT style this method is never called.

Methods inherited from class org.castor.cpa.persistence.sql.keygen.AbstractBeforeKeyGenerator

bindIdentity, buildStatement, executeStatement

Methods inherited from class org.castor.cpa.persistence.sql.keygen.AbstractKeyGenerator

closeSeparateConnection, getSeparateConnection

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MaxKeyGenerator

public MaxKeyGenerator(PersistenceFactory factory,
                       int sqlType)
                throws MappingException

Initialize the MAX key generator.

Parameters:

factory - A PersistenceFactory instance.

sqlType - A SQLTypidentifier.

Throws:

MappingException - if this key generator is not compatible with the persistance factory.

Method Detail

generateKey

public java.lang.Object generateKey(java.sql.Connection conn,
                                    java.lang.String tableName,
                                    java.lang.String primKeyName)
                             throws PersistenceException

Generate a new key for the specified table as "MAX(primary_key) + 1". If there is no records in the table, then the value 1 is returned.
Generate a new key for the specified table. This method is called when a new object is about to be created. In some environments the name of the owner of the object is known, e.g. the principal in a J2EE server. This method is never called for DURING_INSERT key generators.

Parameters:

conn - An open connection within the given transaction

tableName - The table name

primKeyName - The primary key name

Returns:

A new key

Throws:

PersistenceException - An error occured talking to persistent storage

isInSameConnection

public boolean isInSameConnection()

Is key generated in the same connection as INSERT? For DURING_INSERT style this method is never called.

Returns:

{code}True{code} If this instance is in same JDBC Connection.