org.springframework.jdbc.support.incrementer
Class MySQLMaxValueIncrementer

java.lang.Object
  extended by org.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer
      extended by org.springframework.jdbc.support.incrementer.AbstractColumnMaxValueIncrementer
          extended by org.springframework.jdbc.support.incrementer.MySQLMaxValueIncrementer
All Implemented Interfaces:
InitializingBean, DataFieldMaxValueIncrementer

public class MySQLMaxValueIncrementer
extends AbstractColumnMaxValueIncrementer

DataFieldMaxValueIncrementer that increments the 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:
Jean-Pierre Pawlak, Thomas Risberg, Juergen Hoeller

Field Summary
 
Fields inherited from class org.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer
paddingLength
 
Constructor Summary
MySQLMaxValueIncrementer()
          Default constructor for bean property style usage.
MySQLMaxValueIncrementer(javax.sql.DataSource dataSource, java.lang.String incrementerName, java.lang.String columnName)
          Convenience constructor.
 
Method Summary
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

MySQLMaxValueIncrementer

public MySQLMaxValueIncrementer()
Default constructor for bean property style usage.

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

MySQLMaxValueIncrementer

public MySQLMaxValueIncrementer(javax.sql.DataSource dataSource,
                                java.lang.String incrementerName,
                                java.lang.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