org.openware.job.ejb
Class SimpleKeyGen

java.lang.Object
  |
  +--org.openware.job.ejb.KeyGen
        |
        +--org.openware.job.ejb.SimpleKeyGen

public class SimpleKeyGen

extends KeyGen

A simple primary key generator that uses an algorithm that is basically a Hi/Lo algorithm. Basically, it reads a key value from the database, adds 1000 to it and writes it back to the database. After this, the next 1000 keys are derived without accessing the database. This algorithm should also allow another tool to use the same table for primary key generation.

Requires the following script (converted to your particular database) be added to your database:

     CREATE TABLE job_SequenceTable (
         primKey INT8,
         nextId  INT8
     );
     INSERT INTO SequenceTable (primKey, nextId) VALUES (1, 1);
 

JOB will do this for you normally.

Version:

$Revision: 1.6 $ $Date: 2001/07/12 20:19:14 $

Author:

Vincent Sheffer

Constructor Summary

SimpleKeyGen()

Method Summary

long	nextKey(java.sql.Connection conn, long numToGet) Get the next key in the sequence.

Methods inherited from class org.openware.job.ejb.KeyGen

getInstance

Methods inherited from class java.lang.Object

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

Constructor Detail

SimpleKeyGen

public SimpleKeyGen()

Method Detail

nextKey

public long nextKey(java.sql.Connection conn,
                    long numToGet)
             throws java.sql.SQLException

Get the next key in the sequence.

NOTE: This method should be called from inside a transaction.

Overrides:

nextKey in class KeyGen

Parameters:

conn - The database connection to use when the value must come from the database table.