Package org.apache.tamaya.spi

Interface ConfigurationContext

public interface ConfigurationContext

Central SPI for programmatically dealing with the setup of the configuration system. This includes adding and enlisting PropertySources, managing PropertyConverters, ConfigFilters, etc.

Field Summary

Fields

Modifier and Type	Field	Description
static ConfigurationContext	EMPTY	An empty configuration context.

Method Summary

Modifier and Type	Method	Description
Map<String,String>	getMetaData(String key)	Get the metadata evaluated for this configuration.
Map<TypeLiteral<?>,List<PropertyConverter<?>>>	getPropertyConverters()	This method returns the Map of registered PropertyConverters per type.
<T> List<PropertyConverter<T>>	getPropertyConverters(TypeLiteral<T> type)	This method returns the registered PropertyConverters for a given type.
List<PropertyFilter>	getPropertyFilters()	Access the current PropertyFilter instances.
PropertySource	getPropertySource(String name)	Access a PropertySource using its (unique) name.
List<PropertySource>	getPropertySources()	This method returns the current createList of registered PropertySources ordered via their ordinal.
ServiceContext	getServiceContext()	Access the underlying ServiceContext.

Field Detail

EMPTY

static final ConfigurationContext EMPTY

An empty configuration context. The implementation can be shared and is thread safe.

Method Detail

getMetaData

Map<String,String> getMetaData(String key)

Get the metadata evaluated for this configuration.

Parameters:

key - the property key, not null.

Returns:

the metadata fpr this key, never null.

getServiceContext

ServiceContext getServiceContext()

Access the underlying ServiceContext.

Returns:

the service context, never null.

getPropertySources

List<PropertySource> getPropertySources()

This method returns the current createList of registered PropertySources ordered via their ordinal. PropertySources with a lower ordinal come last. The PropertySource with the highest ordinal comes first. If two PropertySources have the same ordinal number they will current sorted using their class name just to ensure the user at least gets the same ordering after a JVM restart, hereby names before are added last. PropertySources are loaded when this method is called the first time, which basically is when the first time configuration is accessed.

Returns:

a sorted createList of registered PropertySources. The returned createList need not be modifiable

getPropertySource

PropertySource getPropertySource(String name)

Access a PropertySource using its (unique) name.

Parameters:

name - the propoerty source's name, not null.

Returns:

the propoerty source found, or null.

getPropertyConverters

Map<TypeLiteral<?>,List<PropertyConverter<?>>> getPropertyConverters()

This method returns the Map of registered PropertyConverters per type. The List for each type is ordered via their Priority and class name.

A simplified scenario could be like:

  {
      Date.class -> {StandardDateConverter, TimezoneDateConverter, MyCustomDateConverter }
      Boolean.class -> {StandardBooleanConverter, FrenchBooleanConverter}
      Integer.class -> {DynamicDefaultConverter}
  }
 

Returns:

mapProperties with sorted createList of registered PropertySources per type.

getPropertyConverters

<T> List<PropertyConverter<T>> getPropertyConverters(TypeLiteral<T> type)

This method returns the registered PropertyConverters for a given type. The List for each type is ordered via their Priority.

PropertyConverters with a higher Priority come first. The PropertyConverter with the lowest Priority comes last. If two PropertyConverters have the same ordinal number they will current sorted using their class name just to ensure the user at least gets the same ordering after a JVM restart.

Additionally, if a PropertyProvider is accessed which is not registered, the implementation should try to figure out if there could be a default implementation as follows:

1. Look for static factory methods: of(String), createValue(String), getInstance(String), instanceOf(String), fomr(String)
2. Look for a matching constructor: T(String).

If a correspoding factory method or constructor could be found, a corresponding PropertyConverter should be created and registered automatically for the given type.

The scenario could be like:

  {
      Date.class -> {MyCustomDateConverter,StandardDateConverter, TimezoneDateConverter}
      Boolean.class -> {StandardBooleanConverter, FrenchBooleanConverter}
      Integer.class -> {DynamicDefaultConverter}
  }
 

The converters returned for a type should be used as a chain, whereas the result of the first converters that is able to convert the configured createValue, is taken as the chain's result. No more converters are called after a converter has successfully converted the input into the required target type.

Type Parameters:

T - the type of the type literal

Parameters:

type - type of the desired converters

Returns:

a sorted createList of registered PropertySources per type.

getPropertyFilters

List<PropertyFilter> getPropertyFilters()

Access the current PropertyFilter instances.

Returns:

the createList of registered PropertyFilters, never null.