org.springframework.jdbc.support.incrementer

Class SqlServerMaxValueIncrementer

java.lang.Object

org.springframework.jdbc.support.incrementer.AbstractDataFieldMaxValueIncrementer

org.springframework.jdbc.support.incrementer.AbstractColumnMaxValueIncrementer

org.springframework.jdbc.support.incrementer.SqlServerMaxValueIncrementer

All Implemented Interfaces:

InitializingBean, DataFieldMaxValueIncrementer

public class SqlServerMaxValueIncrementer
extends AbstractColumnMaxValueIncrementer

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

This class is inteded to be used with Microsoft SQL Server.

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 (id bigint identity)
 insert into tab_sequence default values

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. HINT: Since Microsoft SQL Server supports the JDBC 3.0 getGeneratedKeys method, it is recommended to use IDENTITY columns directly in the tables and then using a SimpleJdbcInsert or utilizing a KeyHolder when calling the with the update(PreparedStatementCreator psc, KeyHolder generatedKeyHolder) method of the JdbcTemplate.

Thanks to Preben Nilsson for the suggestion!

Since:

2.5.5

Author:

Thomas Risberg

Field Summary

Fields

Modifier and Type	Field and Description
private int	nextValueIndex The next id to serve from the value cache
private long[]	valueCache The current cache of values

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

paddingLength

Constructor Summary

Constructors

Constructor and Description
SqlServerMaxValueIncrementer() Default constructor for bean property style usage.
SqlServerMaxValueIncrementer(javax.sql.DataSource dataSource, java.lang.String incrementerName, java.lang.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

Field Detail

valueCache

private long[] valueCache

The current cache of values

nextValueIndex

private int nextValueIndex

The next id to serve from the value cache

Constructor Detail

SqlServerMaxValueIncrementer

public SqlServerMaxValueIncrementer()

Default constructor for bean property style usage.

See Also:

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

SqlServerMaxValueIncrementer

public SqlServerMaxValueIncrementer(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