org.eclipse.microprofile.config

Interface Config

@ProviderType
public interface Config

Resolves the property value by searching through all configured ConfigSources. If the same property is specified in multiple ConfigSources, the value in the ConfigSource with the highest ordinal will be used.

If multiple ConfigSources are specified with the same ordinal, the ConfigSource.getName() will be used for sorting.

The config objects produced via the injection model @Inject Config are guaranteed to be serializable, while the programmatically created ones are not required to be serializable.

If one or more converters are registered for a class of a requested value then the registered Converter which has the highest @javax.annotation.Priority is used to convert the string value retrieved from the config sources.

Usage

For accessing the config you can use the ConfigProvider:

 public void doSomething(
   Config cfg = ConfigProvider.getConfig();
   String archiveUrl = cfg.getValue("my.project.archive.endpoint", String.class);
   Integer archivePort = cfg.getValue("my.project.archive.port", Integer.class);
 

It is also possible to inject the Config if a DI container is available:

 public class MyService {
     @Inject
     private Config config;
 }
 

See getValue(String, Class) and getOptionalValue(String, Class) for accessing a configured value.

Configured values can also be accessed via injection. See ConfigProperty for more information.

Author:

Mark Struberg, Gerhard Petracek, Ron Smeral, Emily Jiang, Gunnar Morling

Method Summary

Modifier and Type	Method and Description
Iterable<ConfigSource>	getConfigSources() Return all of the currently registered configuration sources for this configuration.
<T> Optional<T>	getOptionalValue(String propertyName, Class<T> propertyType) Return the resolved property value with the specified type for the specified property name from the underlying configuration sources.
Iterable<String>	getPropertyNames() Return all property names returned by any of the underlying configuration sources.
<T> T	getValue(String propertyName, Class<T> propertyType) Return the resolved property value with the specified type for the specified property name from the underlying configuration sources.

Method Detail

getValue

<T> T getValue(String propertyName,
               Class<T> propertyType)

Return the resolved property value with the specified type for the specified property name from the underlying configuration sources.

The configuration value is not guaranteed to be cached by the implementation, and may be expensive to compute; therefore, if the returned value is intended to be frequently used, callers should consider storing rather than recomputing it.

Type Parameters:

T - The property type

Parameters:

propertyName - The configuration property name

propertyType - The type into which the resolved property value should get converted

Returns:

the resolved property value as an instance of the requested type

Throws:

IllegalArgumentException - if the property cannot be converted to the specified type

NoSuchElementException - if the property isn't present in the configuration

getOptionalValue

<T> Optional<T> getOptionalValue(String propertyName,
                                 Class<T> propertyType)

Return the resolved property value with the specified type for the specified property name from the underlying configuration sources.

The configuration value is not guaranteed to be cached by the implementation, and may be expensive to compute; therefore, if the returned value is intended to be frequently used, callers should consider storing rather than recomputing it. If this method is used very often then consider to locally store the configured value.

Type Parameters:

T - The property type

Parameters:

propertyName - The configuration property name

propertyType - The type into which the resolved property value should be converted

Returns:

The resolved property value as an Optional wrapping the requested type

Throws:

IllegalArgumentException - if the property cannot be converted to the specified type

getPropertyNames

Iterable<String> getPropertyNames()

Return all property names returned by any of the underlying configuration sources. The order of the returned property names is unspecified.

Returns:

the names of all configured keys of the underlying configuration.

getConfigSources

Iterable<ConfigSource> getConfigSources()

Return all of the currently registered configuration sources for this configuration. The returned sources will be sorted by descending ordinal value and name, which can be iterated in a thread-safe manner.

Returns:

the configuration sources