org.springframework.jdbc.support.incrementer
Class MySQLMaxValueIncrementer

java.lang.Object
  org.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer
      org.springframework.jdbc.support.incrementer.MySQLMaxValueIncrementer

All Implemented Interfaces:

DataFieldMaxValueIncrementer, InitializingBean

public class MySQLMaxValueIncrementer

extends AbstractDataFieldMaxValueIncrementer

Class to increment maximum value of a given MySQL table with the equivalent of an auto-increment column. Note: If you use this class, your MySQL 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. The table type of the sequence table should be MyISAM so the sequences are allocated without regard to any transactions that might be in progress.

Example:

 create table tab (id int unsigned not null primary key, text varchar(100));
 create table tab_sequence (value int not null) type=MYISAM;
 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.

Author:

Isabelle Muszynski, Jean-Pierre Pawlak, Thomas Risberg

Field Summary

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

paddingLength

Constructor Summary

MySQLMaxValueIncrementer()
Default constructor.

MySQLMaxValueIncrementer(DataSource ds, String incrementerName, String columnName)
Convenience constructor.

Method Summary

void	afterPropertiesSet() Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
int	getCacheSize() Return the number of buffered keys.
String	getColumnName() Return the name of the column in the sequence table.
protected long	getNextKey() Determine the next key to use, as a long.
void	setCacheSize(int cacheSize) Set the number of buffered keys.
void	setColumnName(String columnName) Set the name of the column in the sequence table.

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

MySQLMaxValueIncrementer

public MySQLMaxValueIncrementer()

Default constructor.

MySQLMaxValueIncrementer

public MySQLMaxValueIncrementer(DataSource ds,
                                String incrementerName,
                                String columnName)

Convenience constructor.

Parameters:

ds - 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

setColumnName

public void setColumnName(String columnName)

Set the name of the column in the sequence table.

getColumnName

public String getColumnName()

Return the name of the column in the sequence table.

setCacheSize

public void setCacheSize(int cacheSize)

Set the number of buffered keys.

getCacheSize

public int getCacheSize()

Return the number of buffered keys.

afterPropertiesSet

public void afterPropertiesSet()

Description copied from interface: InitializingBean

Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).

This method allows the bean instance to perform initialization only possible when all bean properties have been set and to throw an exception in the event of misconfiguration.

Specified by:

afterPropertiesSet in interface InitializingBean

Overrides:

afterPropertiesSet in class AbstractDataFieldMaxValueIncrementer

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