KeyGenerator (Castor JavaDoc)

All Known Implementing Classes:

AbstractAfterKeyGenerator, AbstractBeforeKeyGenerator, AbstractKeyGenerator, HighLowKeyGenerator, IdentityKeyGenerator, MaxKeyGenerator, NoKeyGenerator, SequenceAfterKeyGenerator, SequenceBeforeKeyGenerator, SequenceDuringKeyGenerator, TableKeyGenerator, UUIDKeyGenerator
```
public interface KeyGenerator
```
Interface for a key generator. The key generator is used for producing identities for objects before they are created in the database.
All the key generators belonging to the same database share the same non-transactional connection to the database.
The key generator is configured from the mapping file using Bean-like accessor methods.

Version:

$Revision: 8639 $ $Date: 2005-04-25 15:33:21 -0600 (Mon, 25 Apr 2005) $

Author:

Assaf Arkin, Oleg Nitz, Bruce Snyder

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`KeyGenerator`	`buildStatement(SQLEngine engine)`	Builds the SQL insert statement.
`java.lang.Object`	`executeStatement(Database database, CastorConnection conn, Identity identity, ProposedEntity entity)`	Executes the SQL statement after preparing the PreparedStatement.
`java.lang.Object`	`generateKey(java.sql.Connection conn, java.lang.String tableName, java.lang.String primKeyName)`	Generate a new key for the specified table.
`boolean`	`isInSameConnection()`	Is key generated in the same connection as INSERT? For DURING_INSERT style this method is never called.

- Method Detail
  - generateKey
```
java.lang.Object generateKey(java.sql.Connection conn,
                             java.lang.String tableName,
                             java.lang.String primKeyName)
                      throws PersistenceException
```
    Generate a new key for the specified table. This method is called when a new object is about to be created. In some environments the name of the owner of the object is known, e.g. the principal in a J2EE server. This method is never called for DURING_INSERT key generators.
    
    Parameters:
    
    conn - An open connection within the given transaction
    
    tableName - The table name
    
    primKeyName - The primary key name
    
    Returns:
    
    A new key
    
    Throws:
    
    PersistenceException - An error occured talking to persistent storage
  - isInSameConnection
```
boolean isInSameConnection()
```
    Is key generated in the same connection as INSERT? For DURING_INSERT style this method is never called.
    
    Returns:
    
    {code}True{code} If this instance is in same JDBC Connection.
  - executeStatement
```
java.lang.Object executeStatement(Database database,
                                  CastorConnection conn,
                                  Identity identity,
                                  ProposedEntity entity)
                           throws PersistenceException
```
    Executes the SQL statement after preparing the PreparedStatement.
    
    Parameters:
    
    database - A database instance.
    
    conn - CastorConnection holding connection and PersistenceFactory to be used to create statement.
    
    identity - Identity of the object to insert.
    
    entity - Entity instance from which field values to be fetached to bind with sql insert statement.
    
    Returns:
    
    Identity
    
    Throws:
    
    PersistenceException - If failed to insert record into database. This could happen if a database access error occurs, If identity size mismatches, unable to retrieve Identity, If provided Identity is null, If Extended engine is null.
  - buildStatement
```
KeyGenerator buildStatement(SQLEngine engine)
```
    Builds the SQL insert statement.
    
    Parameters:
    
    engine - SQL engine for all persistence operations at entities of the type this class is responsible for. Holds all required information of the entity type.
    
    Returns:
    
    KeyGenerator

Interface KeyGenerator

Method Summary

Method Detail

generateKey

isInSameConnection

executeStatement

buildStatement