io.smallrye.config

Interface ConfigSourceInterceptor

All Superinterfaces:

Serializable

All Known Implementing Classes:

ExpressionConfigSourceInterceptor, FallbackConfigSourceInterceptor, LoggingConfigSourceInterceptor, ProfileConfigSourceInterceptor, RelocateConfigSourceInterceptor, SecretKeysConfigSourceInterceptor

@Experimental(value="Interceptor API to intercept resolution of a configuration name")
public interface ConfigSourceInterceptor
extends Serializable

The ConfigSourceInterceptor allows to intercept the resolution of a configuration name before the configuration value is resolved by the Config and before any conversion taking place. It can also intercept iteration of configuration names and values.

This is useful to provide logging, transform names or substitute values.

Implementations of ConfigSourceInterceptor are loaded via the ServiceLoader mechanism and can be registered by providing a resource named META-INF/services/io.smallrye.config.ConfigSourceInterceptor, which contains the fully qualified ConfigSourceInterceptor implementation class name as its content.

Alternatively, a ConfigSourceInterceptor can also be loaded with a ConfigSourceInterceptorFactory.

A ConfigSourceInterceptor implementation class can specify a priority by way of the standard javax.annotation.Priority annotation. If no priority is explicitly assigned, the default priority value of io.smallrye.config.Priorities#APPLICATION is assumed. If multiple interceptors are registered with the same priority, then their execution order may be non deterministic.

Field Summary

Fields

Modifier and Type	Field and Description
static ConfigSourceInterceptor	EMPTY

Method Summary

Modifier and Type	Method and Description
ConfigValue	getValue(ConfigSourceInterceptorContext context, String name) Intercept the resolution of a configuration name and either return the corresponding ConfigValue or a custom ConfigValue built by the interceptor.
default Iterator<String>	iterateNames(ConfigSourceInterceptorContext context) Intercept the resolution of the configuration names.
default Iterator<ConfigValue>	iterateValues(ConfigSourceInterceptorContext context) Intercept the resolution of the configuration ConfigValue.

Field Detail

EMPTY

static final ConfigSourceInterceptor EMPTY

Method Detail

getValue

ConfigValue getValue(ConfigSourceInterceptorContext context,
                     String name)

Intercept the resolution of a configuration name and either return the corresponding ConfigValue or a custom ConfigValue built by the interceptor. Calling ConfigSourceInterceptorContext.proceed(String) will continue to execute the interceptor chain. The chain can be short-circuited by returning another instance of ConfigValue.

Parameters:

context - the interceptor context. See ConfigSourceInterceptorContext

name - the configuration name being intercepted.

Returns:

a ConfigValue with information about the name, value, config source and ordinal, or null if the value isn't present.

iterateNames

default Iterator<String> iterateNames(ConfigSourceInterceptorContext context)

Intercept the resolution of the configuration names. The Iterator names may be a subset of the total names retrieved from all the registered ConfigSources. Calling ConfigSourceInterceptorContext.iterateNames() will continue to execute the interceptor chain. The chain can be short-circuited by returning another instance of the Iterator.

Parameters:

context - the interceptor context. See ConfigSourceInterceptorContext

Returns:

an Iterator of Strings with configuration names.

iterateValues

default Iterator<ConfigValue> iterateValues(ConfigSourceInterceptorContext context)

Intercept the resolution of the configuration ConfigValue. Calling ConfigSourceInterceptorContext.iterateNames() will continue to execute the interceptor chain. The chain can be short-circuited by returning another instance of the Iterator.

Parameters:

context - the interceptor context. See ConfigSourceInterceptorContext

Returns:

an Iterator of ConfigValue with information about the name, value, config source and ordinal.