org.apache.commons.configuration.DatabaseConfiguration

All Implemented Interfaces:: Configuration

public class DatabaseConfiguration extends AbstractConfiguration

Configuration stored in a database. The properties are retrieved from a table containing at least one column for the keys, and one column for the values. It's possible to store several configurations in the same table by adding a column containing the name of the configuration. The name of the table and the columns is specified in the constructor.

Example 1 - One configuration per table

CREATE TABLE myconfig (
    `key`   VARCHAR NOT NULL PRIMARY KEY,
    `value` VARCHAR
);

INSERT INTO myconfig (key, value) VALUES ('foo', 'bar');


Configuration config = new DatabaseConfiguration(datasource, "myconfig", "key", "value");
String value = config.getString("foo");

Example 2 - Multiple configurations per table

CREATE TABLE myconfigs (
    `name`  VARCHAR NOT NULL,
    `key`   VARCHAR NOT NULL,
    `value` VARCHAR,
    CONSTRAINT sys_pk_myconfigs PRIMARY KEY (`name`, `key`)
);

INSERT INTO myconfigs (name, key, value) VALUES ('config1', 'key1', 'value1');
INSERT INTO myconfigs (name, key, value) VALUES ('config2', 'key2', 'value2');


Configuration config1 = new DatabaseConfiguration(datasource, "myconfigs", "name", "key", "value", "config1");
String value1 = conf.getString("key1");

Configuration config2 = new DatabaseConfiguration(datasource, "myconfigs", "name", "key", "value", "config2");
String value2 = conf.getString("key2");

The configuration can be instructed to perform commits after database updates. This is achieved by setting the commits parameter of the constructors to true. If commits should not be performed (which is the default behavior), it should be ensured that the connections returned by the DataSource are in auto-commit mode.

Note: Like JDBC itself, protection against SQL injection is left to the user.

Since:: 1.0
Version:: $Id: DatabaseConfiguration.java 1344442 2012-05-30 20:17:35Z oheger $
Author:: Emmanuel Bourg

Field Summary

Fields inherited from class AbstractConfiguration
END_TOKEN, EVENT_ADD_PROPERTY, EVENT_CLEAR, EVENT_CLEAR_PROPERTY, EVENT_READ_PROPERTY, EVENT_SET_PROPERTY, START_TOKEN
Constructor Summary

Constructors

Constructor

Description

DatabaseConfiguration(DataSource datasource, String table, String keyColumn, String valueColumn)

Build a configuration from a table.

DatabaseConfiguration(DataSource datasource, String table, String keyColumn, String valueColumn, boolean commits)

Creates a new instance of DatabaseConfiguration that operates on a database table containing a single configuration only.

DatabaseConfiguration(DataSource datasource, String table, String nameColumn, String keyColumn, String valueColumn, String name)

Build a configuration from a table containing multiple configurations.

DatabaseConfiguration(DataSource datasource, String table, String nameColumn, String keyColumn, String valueColumn, String name, boolean commits)

Creates a new instance of DatabaseConfiguration that operates on a database table containing multiple configurations.
Method Summary

Modifier and Type

Method

Description

void

addProperty(String key, Object value)

Adds a property to this configuration.

protected void

addPropertyDirect(String key, Object obj)

Adds a property to this configuration.

void

clear()

Removes all entries from this configuration.

protected void

clearPropertyDirect(String key)

Removes the specified value from this configuration.

boolean

containsKey(String key)

Checks whether this configuration contains the specified key.

protected Connection

getConnection()

Deprecated.
Use a custom data source to change the connection used by the class.

DataSource

getDatasource()

Returns the used DataSource object.

Iterator<String>

getKeys()

Returns an iterator with the names of all properties contained in this configuration.

Object

getProperty(String key)

Returns the value of the specified property.

boolean

isDoCommits()

Returns a flag whether this configuration performs commits after database updates.

boolean

isEmpty()

Checks if this configuration is empty.

Methods inherited from class AbstractConfiguration
addErrorLogListener, append, clearProperty, copy, createInterpolator, getBigDecimal, getBigDecimal, getBigInteger, getBigInteger, getBoolean, getBoolean, getBoolean, getByte, getByte, getByte, getDefaultListDelimiter, getDelimiter, getDouble, getDouble, getDouble, getFloat, getFloat, getFloat, getInt, getInt, getInteger, getInterpolator, getKeys, getList, getList, getListDelimiter, getLogger, getLong, getLong, getLong, getProperties, getProperties, getShort, getShort, getShort, getString, getString, getStringArray, getSubstitutor, interpolate, interpolate, interpolatedConfiguration, interpolateHelper, isDelimiterParsingDisabled, isScalarValue, isThrowExceptionOnMissing, resolveContainerStore, setDefaultListDelimiter, setDelimiter, setDelimiterParsingDisabled, setListDelimiter, setLogger, setProperty, setThrowExceptionOnMissing, subset

Methods inherited from class EventSource
addConfigurationListener, addErrorListener, clearConfigurationListeners, clearErrorListeners, clone, createErrorEvent, createEvent, fireError, fireEvent, getConfigurationListeners, getErrorListeners, isDetailEvents, removeConfigurationListener, removeErrorListener, setDetailEvents

Methods inherited from class Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details
- DatabaseConfiguration
  
  public DatabaseConfiguration(DataSource datasource, String table, String nameColumn, String keyColumn, String valueColumn, String name)
  
  Build a configuration from a table containing multiple configurations. No commits are performed by the new configuration instance.
  
  Parameters:
  
  datasource - the datasource to connect to the database
  
  table - the name of the table containing the configurations
  
  nameColumn - the column containing the name of the configuration
  
  keyColumn - the column containing the keys of the configuration
  
  valueColumn - the column containing the values of the configuration
  
  name - the name of the configuration
- DatabaseConfiguration
  
  public DatabaseConfiguration(DataSource datasource, String table, String nameColumn, String keyColumn, String valueColumn, String name, boolean commits)
  
  Creates a new instance of DatabaseConfiguration that operates on a database table containing multiple configurations.
  
  Parameters:
  
  datasource - the DataSource to connect to the database
  
  table - the name of the table containing the configurations
  
  nameColumn - the column containing the name of the configuration
  
  keyColumn - the column containing the keys of the configuration
  
  valueColumn - the column containing the values of the configuration
  
  name - the name of the configuration
  
  commits - a flag whether the configuration should perform a commit after a database update
- DatabaseConfiguration
  
  public DatabaseConfiguration(DataSource datasource, String table, String keyColumn, String valueColumn)
  
  Build a configuration from a table.
  
  Parameters:
  
  datasource - the datasource to connect to the database
  
  table - the name of the table containing the configurations
  
  keyColumn - the column containing the keys of the configuration
  
  valueColumn - the column containing the values of the configuration
- DatabaseConfiguration
  
  public DatabaseConfiguration(DataSource datasource, String table, String keyColumn, String valueColumn, boolean commits)
  
  Creates a new instance of DatabaseConfiguration that operates on a database table containing a single configuration only.
  
  Parameters:
  
  datasource - the DataSource to connect to the database
  
  table - the name of the table containing the configurations
  
  keyColumn - the column containing the keys of the configuration
  
  valueColumn - the column containing the values of the configuration
  
  commits - a flag whether the configuration should perform a commit after a database update
Method Details
- isDoCommits
  
  public boolean isDoCommits()
  
  Returns a flag whether this configuration performs commits after database updates.
  
  Returns:
  
  a flag whether commits are performed
- getProperty
  
  public Object getProperty(String key)
  
  Returns the value of the specified property. If this causes a database error, an error event will be generated of type EVENT_READ_PROPERTY with the causing exception. The event's propertyName is set to the passed in property key, the propertyValue is undefined.
  
  Parameters:
  
  key - the key of the desired property
  
  Returns:
  
  the value of this property
- addPropertyDirect
  
  protected void addPropertyDirect(String key, Object obj)
  
  Adds a property to this configuration. If this causes a database error, an error event will be generated of type EVENT_ADD_PROPERTY with the causing exception. The event's propertyName is set to the passed in property key, the propertyValue points to the passed in value.
  
  Specified by:
  
  addPropertyDirect in class AbstractConfiguration
  
  Parameters:
  
  key - the property key
  
  obj - the value of the property to add
- addProperty
  
  public void addProperty(String key, Object value)
  
  Adds a property to this configuration. This implementation will temporarily disable list delimiter parsing, so that even if the value contains the list delimiter, only a single record will be written into the managed table. The implementation of getProperty() will take care about delimiters. So list delimiters are fully supported by DatabaseConfiguration, but internally treated a bit differently.
  
  Specified by:
  
  addProperty in interface Configuration
  
  Overrides:
  
  addProperty in class AbstractConfiguration
  
  Parameters:
  
  key - the key of the new property
  
  value - the value to be added
- isEmpty
  
  public boolean isEmpty()
  
  Checks if this configuration is empty. If this causes a database error, an error event will be generated of type EVENT_READ_PROPERTY with the causing exception. Both the event's propertyName and propertyValue will be undefined.
  
  Returns:
  
  a flag whether this configuration is empty.
- containsKey
  
  public boolean containsKey(String key)
  
  Checks whether this configuration contains the specified key. If this causes a database error, an error event will be generated of type EVENT_READ_PROPERTY with the causing exception. The event's propertyName will be set to the passed in key, the propertyValue will be undefined.
  
  Parameters:
  
  key - the key to be checked
  
  Returns:
  
  a flag whether this key is defined
- clearPropertyDirect
  
  protected void clearPropertyDirect(String key)
  
  Removes the specified value from this configuration. If this causes a database error, an error event will be generated of type EVENT_CLEAR_PROPERTY with the causing exception. The event's propertyName will be set to the passed in key, the propertyValue will be undefined.
  
  Overrides:
  
  clearPropertyDirect in class AbstractConfiguration
  
  Parameters:
  
  key - the key of the property to be removed
- clear
  
  public void clear()
  
  Removes all entries from this configuration. If this causes a database error, an error event will be generated of type EVENT_CLEAR with the causing exception. Both the event's propertyName and the propertyValue will be undefined.
  
  Specified by:
  
  clear in interface Configuration
  
  Overrides:
  
  clear in class AbstractConfiguration
- getKeys
  
  public Iterator<String> getKeys()
  
  Returns an iterator with the names of all properties contained in this configuration. If this causes a database error, an error event will be generated of type EVENT_READ_PROPERTY with the causing exception. Both the event's propertyName and the propertyValue will be undefined.
  
  Returns:
  
  an iterator with the contained keys (an empty iterator in case of an error)
- getDatasource
  
  public DataSource getDatasource()
  
  Returns the used DataSource object.
  
  Returns:
  
  the data source
  
  Since:
  
  1.4
- getConnection
  
  @Deprecated protected Connection getConnection() throws SQLException
  
  Deprecated.
  Use a custom data source to change the connection used by the class. To be removed in Commons Configuration 2.0
  
  Returns a Connection object. This method is called when ever the database is to be accessed. This implementation returns a connection from the current DataSource.
  
  Returns:
  
  the Connection object to be used
  
  Throws:
  
  SQLException - if an error occurs
  
  Since:
  
  1.4

Class DatabaseConfiguration

Example 1 - One configuration per table

Example 2 - Multiple configurations per table

Note: Like JDBC itself, protection against SQL injection is left to the user.

Field Summary

Fields inherited from class AbstractConfiguration

Constructor Summary

Method Summary

Methods inherited from class AbstractConfiguration

Methods inherited from class EventSource

Methods inherited from class Object

Constructor Details

DatabaseConfiguration

DatabaseConfiguration

DatabaseConfiguration

DatabaseConfiguration

Method Details

isDoCommits

getProperty

addPropertyDirect

addProperty

isEmpty

containsKey

clearPropertyDirect

clear

getKeys

getDatasource

getConnection