Class HsqlMaxValueIncrementer

  extended by
      extended by
          extended by
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.


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

Jean-Pierre Pawlak, Thomas Risberg, Juergen Hoeller
See Also:

Field Summary
Fields inherited from class
Constructor Summary
          Default constructor for bean property style usage.
HsqlMaxValueIncrementer(DataSource dataSource, String incrementerName, String columnName)
          Convenience constructor.
Method Summary
protected  long getNextKey()
          Determine the next key to use, as a long.
Methods inherited from class
afterPropertiesSet, getCacheSize, getColumnName, setCacheSize, setColumnName
Methods inherited from class
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


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)


public HsqlMaxValueIncrementer(DataSource dataSource,
                               String incrementerName,
                               String columnName)
Convenience constructor.

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


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

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