org.apache.deltaspike.core.spi.config

Interface ConfigSource

All Known Implementing Classes:

CdiTestSuiteRunner.TestConfigSource

public interface ConfigSource

Implement this interfaces to provide a ConfigSource. A ConfigSource provides properties from a specific place, like JNDI configuration, a properties file, etc

The custom implementation can be 'registered' using a ConfigSourceProvider or via the ServiceLoader mechanism. In the later case it must get registered via creating a META-INF/services/org.apache.deltaspike.core.spi.config.ConfigSource file and adding the fully qualified class name of your ConfigSource implementation into it.

If a ConfigSource implements the AutoCloseable interface it will automatically be released when the Config is shut down.

Field Summary

Fields

Modifier and Type	Field and Description
static String	DELTASPIKE_ORDINAL The default name for the ordinal field.

Method Summary

Modifier and Type	Method and Description
String	getConfigName()
int	getOrdinal() Lookup order: System properties (ordinal 400) Environment properties (ordinal 300) JNDI values (ordinal 200) Properties file values (/META-INF/apache-deltaspike.properties) (ordinal 100) Important Hints for custom implementations: If a custom implementation should be invoked before the default implementations, use a value > 400 If a custom implementation should be invoked after the default implementations, use a value < 100 IMPORTANT: Have a look at the abstract base-implementation DeltaSpike is using internally, if a custom implementation should load the ordinal value from the config-source like the default implementations provided by DeltaSpike do.
Map<String,String>	getProperties() Return properties contained in this config source.
String	getPropertyValue(String key)
boolean	isScannable() Determines if this config source should be scanned for its list of properties.
default void	setOnAttributeChange(Consumer<Set<String>> reportAttributeChange) This callback should get invoked if an attribute change got detected inside the ConfigSource.

Field Detail

DELTASPIKE_ORDINAL

static final String DELTASPIKE_ORDINAL

The default name for the ordinal field. Any ConfigSource might use it's own though or even return a hardcoded in getOrdinal().

See Also:

Constant Field Values

Method Detail

getOrdinal

int getOrdinal()

Lookup order:

1. System properties (ordinal 400)
2. Environment properties (ordinal 300)
3. JNDI values (ordinal 200)
4. Properties file values (/META-INF/apache-deltaspike.properties) (ordinal 100)

Important Hints for custom implementations:

If a custom implementation should be invoked before the default implementations, use a value > 400

If a custom implementation should be invoked after the default implementations, use a value < 100

IMPORTANT: Have a look at the abstract base-implementation DeltaSpike is using internally, if a custom implementation should load the ordinal value from the config-source like the default implementations provided by DeltaSpike do.

Reordering of the default order of the config-sources:

Example: If the properties file/s should be used before the other implementations, you have to configure an ordinal > 400. That means, you have to add e.g. deltaspike_ordinal=401 to /META-INF/apache-deltaspike.properties . Hint: In case of property files every file is handled as independent config-source, but all of them have ordinal 400 by default (and can be reordered in a fine-grained manner.

Returns:

the 'importance' aka ordinal of the configured values. The higher, the more important.

getProperties

Map<String,String> getProperties()

Return properties contained in this config source.

Returns:

Properties available in this config source.

getPropertyValue

String getPropertyValue(String key)

Parameters:

key - for the property

Returns:

configured value or null if this ConfigSource doesn't provide any value for the given key.

getConfigName

String getConfigName()

Returns:

the 'name' of the configuration source, e.g. 'property-file mylocation/myproperty.properties'

isScannable

boolean isScannable()

Determines if this config source should be scanned for its list of properties. Generally, slow ConfigSources should return false here.

Returns:

true if this ConfigSource should be scanned for its list of properties, false if it should not be scanned.

setOnAttributeChange

default void setOnAttributeChange(Consumer<Set<String>> reportAttributeChange)

This callback should get invoked if an attribute change got detected inside the ConfigSource. An example would be a database backed ConfigSource which scans the DB every second in a background task. And once it detects a change in values, it will notify the Config about the changed attributes by invoking reportAttributeChange.accept(changedKeys);

Parameters:

reportAttributeChange - will be set by the Config after this ConfigSource got created and before any configured values get served.