org.exolab.castor.jdo.keygen

Class MaxKeyGenerator

java.lang.Object

org.exolab.castor.jdo.keygen.MaxKeyGenerator

All Implemented Interfaces:

KeyGenerator

public final class MaxKeyGenerator
extends java.lang.Object
implements KeyGenerator

MAX key generator.

Version:

$Revision: 5951 $ $Date: 2006-04-10 16:39:24 -0600 (Mon, 10 Apr 2006) $

Author:

Oleg Nitz, Leonardo Souza Mario Bueno, Bruce Snyder

See Also:

MaxKeyGeneratorFactory

Field Summary

Fields inherited from interface org.exolab.castor.persist.spi.KeyGenerator

AFTER_INSERT, BEFORE_INSERT, DURING_INSERT

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method and Description
java.lang.Object	generateKey(java.sql.Connection conn, java.lang.String tableName, java.lang.String primKeyName, java.util.Properties props) Generate a new key for the specified table as "MAX(primary_key) + 1".
byte	getStyle() Style of key generator: BEFORE_INSERT, DURING_INSERT or AFTER_INSERT ?
boolean	isInSameConnection() Is key generated in the same connection as INSERT?
java.lang.String	patchSQL(java.lang.String insert, java.lang.String primKeyName) Gives a possibility to patch the Castor-generated SQL statement for INSERT (makes sense for DURING_INSERT key generators)
void	supportsSqlType(int sqlType) Determine if the key generator supports a given sql type.

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.

Throws:

MappingException

Method Detail

supportsSqlType

public void supportsSqlType(int sqlType)
                     throws MappingException

Determine if the key generator supports a given sql type.

Specified by:

supportsSqlType in interface KeyGenerator

Parameters:

sqlType -

Throws:

MappingException

generateKey

public java.lang.Object generateKey(java.sql.Connection conn,
                                    java.lang.String tableName,
                                    java.lang.String primKeyName,
                                    java.util.Properties props)
                             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.

Specified by:

generateKey in interface KeyGenerator

Parameters:

conn - An open connection within the given transaction

tableName - The table name

primKeyName - The primary key name

props - A temporary replacement for Principal object

Returns:

A new key

Throws:

PersistenceException - An error occured talking to persistent storage

getStyle

public final byte getStyle()

Style of key generator: BEFORE_INSERT, DURING_INSERT or AFTER_INSERT ?

Specified by:

getStyle in interface KeyGenerator

patchSQL

public final java.lang.String patchSQL(java.lang.String insert,
                                       java.lang.String primKeyName)

Gives a possibility to patch the Castor-generated SQL statement for INSERT (makes sense for DURING_INSERT key generators)

Specified by:

patchSQL in interface KeyGenerator

Parameters:

insert - Castor-generated INSERT statement

primKeyName - The primary key name

isInSameConnection

public boolean isInSameConnection()

Is key generated in the same connection as INSERT?

Specified by:

isInSameConnection in interface KeyGenerator