org.ujorm.orm
Class UjoSequencer

java.lang.Object
  org.ujorm.orm.UjoSequencer

Direct Known Subclasses:

NativeDbSequencer

public class UjoSequencer
extends Object

The default sequence provider. A result value is recieved from a special database table.

Field Summary

protected long	maxValue Total limit, zero means no restriction
static int	SEQ_LIMIT DB field: seqLimit
static int	SEQ_MAX_VALUE DB field: maxValue
static int	SEQ_STEP DB field: step
protected long	seqLimit Buffer limit
protected long	sequence Current sequence value
protected MetaTable	table Basic table.

Constructor Summary

UjoSequencer(MetaTable table)

Method Summary

protected int	executeSql(Connection connection, String sql, String tableName) Executes UPDATE for required parameters
long[]	getCurrentDBSequence(Connection connection, StringBuilder sql) Returns current db sequence for an actual table with a performance optimizations.
MetaDatabase	getDatabase() Returns model of the database
String	getDatabaseSchema() Returns the database schema
int	getIncrement() The UJO cache is the number of pre-allocated numbers inside the OrmUjo framework.
int	getInitDbCache() The cache of a database sequence is zero by default.
MetaTable	getTable() Returns a related table or null if sequence is general for the all MetaDatabase space
boolean	isSequenceTableRequired() Method returns true because the internal table 'ujorm_pk_support' is required to get a next sequence value.
long	nextValue(Session session) Returns the next sequence value by a synchronized method.
void	reset() Forces to reload sequence from db on next call for nextValue.

Methods inherited from class java.lang.Object

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

Field Detail

SEQ_LIMIT

public static final int SEQ_LIMIT

DB field: seqLimit

See Also:

Constant Field Values

SEQ_STEP

public static final int SEQ_STEP

DB field: step

See Also:

Constant Field Values

SEQ_MAX_VALUE

public static final int SEQ_MAX_VALUE

DB field: maxValue

See Also:

Constant Field Values

table

protected final MetaTable table

Basic table.

sequence

protected long sequence

Current sequence value

seqLimit

protected long seqLimit

Buffer limit

maxValue

protected long maxValue

Total limit, zero means no restriction

Constructor Detail

UjoSequencer

public UjoSequencer(MetaTable table)

Method Detail

nextValue

public long nextValue(Session session)

Returns the next sequence value by a synchronized method.

getDatabaseSchema

public String getDatabaseSchema()

Returns the database schema

getIncrement

public int getIncrement()

The UJO cache is the number of pre-allocated numbers inside the OrmUjo framework.

getInitDbCache

public int getInitDbCache()

The cache of a database sequence is zero by default.

getDatabase

public MetaDatabase getDatabase()

Returns model of the database

getTable

public MetaTable getTable()

Returns a related table or null if sequence is general for the all MetaDatabase space

isSequenceTableRequired

public boolean isSequenceTableRequired()

Method returns true because the internal table 'ujorm_pk_support' is required to get a next sequence value. In case you have a different imlementation, there is possible overwrite this method and return an another value.

reset

public void reset()

Forces to reload sequence from db on next call for nextValue.

getCurrentDBSequence

public long[] getCurrentDBSequence(Connection connection,
                                   StringBuilder sql)
                            throws Exception

Returns current db sequence for an actual table with a performance optimizations.

Parameters:

connection - Connection

sql - Temporarry buffer for a better performance. The value can be null a not null will be cleaned always.

Returns:

Returns current db sequence for an actual table with a value order:
[SEQ_LIMIT, SEQ_STEP, SEQ_MAX_VALUE].
If no sequence is found then the method returns the value null.

Throws:

Exception

executeSql

protected int executeSql(Connection connection,
                         String sql,
                         String tableName)
                  throws SQLException

Executes UPDATE for required parameters

Throws:

SQLException