MaxKeyGeneratorFactory (Castor JavaDoc)

java.lang.Object
- org.castor.cpa.persistence.sql.keygen.MaxKeyGeneratorFactory

All Implemented Interfaces:

KeyGeneratorFactory
```
public final class MaxKeyGeneratorFactory
extends java.lang.Object
implements KeyGeneratorFactory
```
MAX key generator factory. The short name of this key generator is "MAX".
It uses the following alrorithm: the maximum value of the primary key is fetched and the correspondent record is locked until the end of transaction, generator returns (max + 1). The lock guarantees that key generators of concurrent transactions will not use this key value, so DuplicateKeyException is impossible. If the table is empty, generator returns 1, no lock is put, DuplicateKeyException is possible.

Version:

$Revision: 8093 $ $Date: 2006-04-25 15:08:23 -0600 (Tue, 25 Apr 2006) $

Author:

Oleg Nitz, Ralf Joachim

See Also:

MaxKeyGenerator

Constructor Summary

Constructors
Constructor and Description

MaxKeyGeneratorFactory()

Constructors
Constructor and Description
`MaxKeyGeneratorFactory()`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`KeyGenerator`	`getKeyGenerator(PersistenceFactory factory, java.util.Properties params, int sqlType)` Produce the key generator.
`java.lang.String`	`getKeyGeneratorName()` Get the short name of the key generator.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - MaxKeyGeneratorFactory
```
public MaxKeyGeneratorFactory()
```
- Method Detail
  - getKeyGeneratorName
```
public java.lang.String getKeyGeneratorName()
```
    Get the short name of the key generator. It is used to reference key generators in a mapping configuration file. If several key generators of the same type are used for the same database, then they are referenced by aliases.
    
    Specified by:
    
    getKeyGeneratorName in interface KeyGeneratorFactory
    
    Returns:
    
    Name of the KeyGenerator used to identify key generator (types).
  - getKeyGenerator
```
public KeyGenerator getKeyGenerator(PersistenceFactory factory,
                                    java.util.Properties params,
                                    int sqlType)
                             throws MappingException
```
    Produce the key generator.
    
    Specified by:
    
    getKeyGenerator in interface KeyGeneratorFactory
    
    Parameters:
    
    factory - Helper object for obtaining database-specific QuerySyntax.
    
    params - Parameters for key generator.
    
    sqlType - The SQL type of the primary key, the generated identities must have the corresponding Java type, e.g. java.sql.Types.INTEGER corresponds to java.lang.Integer, java.sql.Types.NUMERIC corresponds to java.lang.BigDecimal.
    
    Returns:
    
    A KeyGenerator instance.
    
    Throws:
    
    MappingException - If there's a problem resolving the mapping information.

Class MaxKeyGeneratorFactory

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

MaxKeyGeneratorFactory

Method Detail

getKeyGeneratorName

getKeyGenerator