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.

Method Summary

Methods

Modifier and Type	Method and Description
<T> void	addPropertyConverter(TypeLiteral<T> typeToConvert, PropertyConverter<T> propertyConverter) This method can be used for programmatically adding PropertyConverters.
void	addPropertySources(PropertySource... propertySourcesToAdd) This method can be used for programmatically adding PropertySources.
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.
List<PropertySource>	getPropertySources() This method returns the current list of registered PropertySources ordered via their ordinal.
PropertyValueCombinationPolicy	getPropertyValueCombinationPolicy() Access the PropertyValueCombinationPolicy used to evaluate the final property values.
ConfigurationContextBuilder	toBuilder() Creates a ConfigurationContextBuilder preinitialized with the data from this instance.

Method Detail

addPropertySources

void addPropertySources(PropertySource... propertySourcesToAdd)

This method can be used for programmatically adding PropertySources. It is not needed for normal 'usage' by end users, but only for Extension Developers!

Parameters:

propertySourcesToAdd - the PropertySources to add

getPropertySources

List<PropertySource> getPropertySources()

This method returns the current list 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 get 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 list of registered PropertySources. The returned list need not be modifiable

addPropertyConverter

<T> void addPropertyConverter(TypeLiteral<T> typeToConvert,
                            PropertyConverter<T> propertyConverter)

This method can be used for programmatically adding PropertyConverters. It is not needed for normal 'usage' by end users, but only for Extension Developers!

Type Parameters:

T - the type of the type literal

Parameters:

typeToConvert - the type which the converter is for

propertyConverter - the PropertyConverters to add for this type

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 cladd name.

A simplified scenario could be like:

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

Returns:

map with sorted list 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 PropertyConverter have the same ordinal number they will get 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), valueOf(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 converter that is able to convert the configured value, 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 converter

Returns:

a sorted list of registered PropertySources per type.

getPropertyFilters

List<PropertyFilter> getPropertyFilters()

Access the current PropertyFilter instances.

Returns:

the list of registered PropertyFilters, never null.

getPropertyValueCombinationPolicy

PropertyValueCombinationPolicy getPropertyValueCombinationPolicy()

Access the PropertyValueCombinationPolicy used to evaluate the final property values.

Returns:

the PropertyValueCombinationPolicy used, never null.

toBuilder

ConfigurationContextBuilder toBuilder()

Creates a ConfigurationContextBuilder preinitialized with the data from this instance.

Returns:

a new builder instance, never null.