org.springframework.jdbc.support.incrementer

Class HsqlMaxValueIncrementer

java.lang.Object

org.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer

org.springframework.jdbc.support.incrementer.AbstractColumnMaxValueIncrementer

org.springframework.jdbc.support.incrementer.HsqlMaxValueIncrementer

All Implemented Interfaces:

InitializingBean, DataFieldMaxValueIncrementer

public class HsqlMaxValueIncrementer
extends AbstractColumnMaxValueIncrementer

DataFieldMaxValueIncrementer that increments the maximum value of a given HSQL table with the equivalent of an auto-increment column. Note: If you use this class, your HSQL key column should NOT be auto-increment, as the sequence table does the job.

The sequence is kept in a table. There should be one sequence table per table that needs an auto-generated key.

Example:

create table tab (id int not null primary key, text varchar(100));
 create table tab_sequence (value identity);
 insert into tab_sequence values(0);

If "cacheSize" is set, the intermediate values are served without querying the database. If the server or your application is stopped or crashes or a transaction is rolled back, the unused values will never be served. The maximum hole size in numbering is consequently the value of cacheSize.

NOTE: HSQL now supports sequences and you should consider using them instead: HsqlSequenceMaxValueIncrementer

Author:

Jean-Pierre Pawlak, Thomas Risberg, Juergen Hoeller

See Also:

HsqlSequenceMaxValueIncrementer

Field Summary

Fields inherited from class org.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer

paddingLength

Constructor Summary

Constructors

Constructor and Description
HsqlMaxValueIncrementer() Default constructor for bean property style usage.
HsqlMaxValueIncrementer(DataSource dataSource, String incrementerName, String columnName) Convenience constructor.

Method Summary

Modifier and Type	Method and Description
protected long	getNextKey() Determine the next key to use, as a long.

Methods inherited from class org.springframework.jdbc.support.incrementer.AbstractColumnMaxValueIncrementer

afterPropertiesSet, getCacheSize, getColumnName, setCacheSize, setColumnName

Methods inherited from class org.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer

getDataSource, getIncrementerName, getPaddingLength, nextIntValue, nextLongValue, nextStringValue, setDataSource, setIncrementerName, setPaddingLength

Methods inherited from class java.lang.Object

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

Constructor Detail

HsqlMaxValueIncrementer

public HsqlMaxValueIncrementer()

Default constructor for bean property style usage.

See Also:

AbstractDataFieldMaxValueIncrementer.setDataSource(javax.sql.DataSource), AbstractDataFieldMaxValueIncrementer.setIncrementerName(java.lang.String), AbstractColumnMaxValueIncrementer.setColumnName(java.lang.String)

HsqlMaxValueIncrementer

public HsqlMaxValueIncrementer(DataSource dataSource,
                               String incrementerName,
                               String columnName)

Convenience constructor.

Parameters:

dataSource - the DataSource to use

incrementerName - the name of the sequence/table to use

columnName - the name of the column in the sequence table to use

Method Detail

getNextKey

protected long getNextKey()
                   throws DataAccessException

Description copied from class: AbstractDataFieldMaxValueIncrementer

Determine the next key to use, as a long.

Specified by:

getNextKey in class AbstractDataFieldMaxValueIncrementer

Returns:

the key to use as a long. It will eventually be converted later in another format by the public concrete methods of this class.

Throws:

DataAccessException