Package org.apache.commons.configuration

Class DatabaseConfiguration

java.lang.Object

org.apache.commons.configuration.event.EventSource

org.apache.commons.configuration.AbstractConfiguration

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 org.apache.commons.configuration.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(javax.sql.DataSource datasource, java.lang.String table, java.lang.String keyColumn, java.lang.String valueColumn)	Build a configuration from a table.
DatabaseConfiguration(javax.sql.DataSource datasource, java.lang.String table, java.lang.String keyColumn, java.lang.String valueColumn, boolean commits)	Creates a new instance of DatabaseConfiguration that operates on a database table containing a single configuration only.
DatabaseConfiguration(javax.sql.DataSource datasource, java.lang.String table, java.lang.String nameColumn, java.lang.String keyColumn, java.lang.String valueColumn, java.lang.String name)	Build a configuration from a table containing multiple configurations.
DatabaseConfiguration(javax.sql.DataSource datasource, java.lang.String table, java.lang.String nameColumn, java.lang.String keyColumn, java.lang.String valueColumn, java.lang.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(java.lang.String key, java.lang.Object value)	Adds a property to this configuration.
protected void	addPropertyDirect(java.lang.String key, java.lang.Object obj)	Adds a property to this configuration.
void	clear()	Removes all entries from this configuration.
protected void	clearPropertyDirect(java.lang.String key)	Removes the specified value from this configuration.
boolean	containsKey(java.lang.String key)	Checks whether this configuration contains the specified key.
protected java.sql.Connection	getConnection()	Deprecated. Use a custom data source to change the connection used by the class. To be removed in Commons Configuration 2.0
javax.sql.DataSource	getDatasource()	Returns the used DataSource object.
java.util.Iterator<java.lang.String>	getKeys()	Returns an iterator with the names of all properties contained in this configuration.
java.lang.Object	getProperty(java.lang.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 org.apache.commons.configuration.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 org.apache.commons.configuration.event.EventSource

addConfigurationListener, addErrorListener, clearConfigurationListeners, clearErrorListeners, clone, createErrorEvent, createEvent, fireError, fireEvent, getConfigurationListeners, getErrorListeners, isDetailEvents, removeConfigurationListener, removeErrorListener, setDetailEvents

Methods inherited from class java.lang.Object

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

Constructor Detail

DatabaseConfiguration

public DatabaseConfiguration(javax.sql.DataSource datasource,
                             java.lang.String table,
                             java.lang.String nameColumn,
                             java.lang.String keyColumn,
                             java.lang.String valueColumn,
                             java.lang.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(javax.sql.DataSource datasource,
                             java.lang.String table,
                             java.lang.String nameColumn,
                             java.lang.String keyColumn,
                             java.lang.String valueColumn,
                             java.lang.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(javax.sql.DataSource datasource,
                             java.lang.String table,
                             java.lang.String keyColumn,
                             java.lang.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(javax.sql.DataSource datasource,
                             java.lang.String table,
                             java.lang.String keyColumn,
                             java.lang.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 Detail

isDoCommits

public boolean isDoCommits()

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

Returns:

a flag whether commits are performed

getProperty

public java.lang.Object getProperty(java.lang.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(java.lang.String key,
                                 java.lang.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(java.lang.String key,
                        java.lang.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(java.lang.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(java.lang.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 java.util.Iterator<java.lang.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 javax.sql.DataSource getDatasource()

Returns the used DataSource object.

Returns:

the data source

Since:

1.4

getConnection

@Deprecated
protected java.sql.Connection getConnection()
                                     throws java.sql.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:

java.sql.SQLException - if an error occurs

Since:

1.4