nl.b3p.viewer.util.databaseupdate

Class DatabaseSynchronizer

java.lang.Object

nl.b3p.viewer.util.databaseupdate.DatabaseSynchronizer

All Implemented Interfaces:

javax.servlet.Servlet

public class DatabaseSynchronizer
extends Object
implements javax.servlet.Servlet

Class for Synchronizing the database with the application entitymodel. The class contains a static script holder ('updates'). With versions and the scripts that are needed for upgrading to that version (from the previous defined version). The version of the database model is stored in the database metadata table. First the class checks if there is a 'metadata' table. If not, we assume the database is empty or without Flamingo tables. All scripts that are defined for version '0' are called: - the (at build) auto generated schema-export script - the init script with data that is needed to start. The database is at the latest defined version (fully up to date) so the latest defined version is set in the metadata tabel. >> Update done. If there is a metadata table and a record with the key Metadata.DATABASE_VERSION_KEY then that is the current version of the database model. All scripts that are defined after that version are loaded and called; updating the database to the entity model. The scripts are stored in: 'src/main/resources/scripts' When adding a new script in that folder just define the script name (without database product name) in the 'updates' param with a new version number. When loading the scripts, the loader is first looking for the script with the defined name. For example 'newscript.sql'. If the script is not found the loader is searching for the script with the name '<database product name in lower case>-<script name>' for example: 'postgresql-newscript.sql'. So when a script is the same for all database products (for example simple inserts) you only need to make 1 script '<script name>'. If there are specific database products statements make multiple scripts and name them '<database product name in lower case>->script name>' in the scripts folder. Add the <script name> in the updates var of this class.

Author:

Roy Braam

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	DatabaseSynchronizer.ScriptWorker

Constructor Summary

Constructors

Constructor and Description
DatabaseSynchronizer()

Method Summary

Modifier and Type	Method and Description
void	destroy()
void	doInit(javax.persistence.EntityManager em) Function is called in init() of servlet.
javax.servlet.ServletConfig	getServletConfig()
String	getServletInfo()
static String	getUpdateNumber() Determine the update number.
void	init(javax.servlet.ServletConfig sc)
void	service(javax.servlet.ServletRequest sr, javax.servlet.ServletResponse sr1)

Methods inherited from class java.lang.Object

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

Constructor Detail

DatabaseSynchronizer

public DatabaseSynchronizer()

Method Detail

getUpdateNumber

public static String getUpdateNumber()

Determine the update number. The updates list has an "init" UpdateElement + a number of numbered patch UpdateElement's, this method returns the key of the last patch.

Returns:

the highest/update metadata number

doInit

public void doInit(javax.persistence.EntityManager em)

Function is called in init() of servlet. Starts the updating process.

Parameters:

em - the entity manager to use

init

public void init(javax.servlet.ServletConfig sc)
          throws javax.servlet.ServletException

Specified by:

init in interface javax.servlet.Servlet

Throws:

javax.servlet.ServletException

getServletConfig

public javax.servlet.ServletConfig getServletConfig()

Specified by:

getServletConfig in interface javax.servlet.Servlet

service

public void service(javax.servlet.ServletRequest sr,
                    javax.servlet.ServletResponse sr1)
             throws javax.servlet.ServletException,
                    IOException

Specified by:

service in interface javax.servlet.Servlet

Throws:

javax.servlet.ServletException

IOException

getServletInfo

public String getServletInfo()

Specified by:

getServletInfo in interface javax.servlet.Servlet

destroy

public void destroy()

Specified by:

destroy in interface javax.servlet.Servlet