biz.chitec.quarterback.util
Class PropertiesStorer

java.lang.Object
  biz.chitec.quarterback.util.PropertiesStorer

public final class PropertiesStorer

extends java.lang.Object

Static helper class to store a Properties object into a database. For this to work, a table has to be defined:

 create table propertiestable (
   name varchar(40) not null default '',
   thekey varchar(255) not null default '',
   thevalue mediumtext not null default '',
   unique (name,thekey)
 );
 

Property tables' names have to be defines uniquely, of course. Storing is done in a way that the least possible information is lost in case of an intermediate crash.

Version:

$Id: aab46855022cadb795457d1199df1372a3f15d29 $

Author:

cantamen/Dirk Hillbrecht 2005

Constructor Summary

private

PropertiesStorer() This is a fully static class

Method Summary

static void	dropProperties(java.sql.Statement dbstmt, java.lang.String propertiesname) Drops a properties object finally from the database.
static java.lang.String	getProperty(java.sql.Statement dbstmt, java.lang.String propertiesname, java.lang.String key, java.lang.String defaultvalue) Get a single property from the database.
static java.util.Properties	loadProperties(java.sql.Statement dbstmt, java.lang.String propertiesname, java.util.Properties defaults) Loads a properties object from the database.
static void	storeProperties(java.sql.Statement dbstmt, java.lang.String propertiesname, java.util.Set allowedkeys, java.util.Properties props) Stores a properties object into the database.

Methods inherited from class java.lang.Object

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

Constructor Detail

PropertiesStorer

private PropertiesStorer()

This is a fully static class

Method Detail

storeProperties

public static void storeProperties(java.sql.Statement dbstmt,
                                   java.lang.String propertiesname,
                                   java.util.Set allowedkeys,
                                   java.util.Properties props)
                            throws java.sql.SQLException

Stores a properties object into the database. The properties object is handled as a complete replacement for all entries in the database. I.e. if an entry is in the database but not in the properties object, it is removed from the database. It is possible to define the given properties object to be only a replacement for parts of the data stored in the database. In this case, "allowedkeys" must be different from null and containing all the keys which should be covered by the contents of the given properties.

The method locks the entries for this properties object as long as it stores them. For this, it uses the RowLock mechanism.

Parameters:

dbstmt - Statement to work on

propertiesname - Name of the properties object

allowedkeys - Complete set of keys which are changeable, null if irrelevant

props - The properties to store

Throws:

java.sql.SQLException - If something goes wrong in the database

loadProperties

public static java.util.Properties loadProperties(java.sql.Statement dbstmt,
                                                  java.lang.String propertiesname,
                                                  java.util.Properties defaults)
                                           throws java.sql.SQLException

Loads a properties object from the database. The method locks the entries for this properties object as long as it loads them.

Parameters:

dbstmt - Statement to work on

propertiesname - Name of the properties table to load

defaults - Default (or "parent") properties for the properties to build, null if none exist

Returns:

Filled properties object

Throws:

java.sql.SQLException

getProperty

public static java.lang.String getProperty(java.sql.Statement dbstmt,
                                           java.lang.String propertiesname,
                                           java.lang.String key,
                                           java.lang.String defaultvalue)
                                    throws java.sql.SQLException

Get a single property from the database. This method should only be used if only one certain value is needed from the properties element. If you need multiple elements, you should always read the complete Properties bundle via loadProperties(Statement, String, Properties).

Parameters:

dbstmt - Statement to work on the database with

propertiesname - Name of the bundle

key - The needed value's key.

defaultvalue - The default value to return if nothing is stored in the database

Returns:

The value stored in the database or the given default value if nothing is stored.

Throws:

java.sql.SQLException - If something goes wrong with the database

dropProperties

public static void dropProperties(java.sql.Statement dbstmt,
                                  java.lang.String propertiesname)
                           throws java.sql.SQLException

Drops a properties object finally from the database. After calling this method, the properties are completely and unrecoverably deleted from the database.

Parameters:

dbstmt - Statement to work on

propertiesname - Name of the properties table to drop

Throws:

java.sql.SQLException