# Package org.apache.lucene.queryparser.flexible.core.config

Base classes used to configure the query processing.

See: Description

Interface Summary
FieldConfigListener: This interface should be implemented by classes that wants to listen for field configuration requests.

Class Summary
AbstractQueryConfig: This class is the base of `QueryConfigHandler` and `FieldConfig`.
ConfigurationKey<T>: An instance of this class represents a key that is used to retrieve a value from `AbstractQueryConfig`.
FieldConfig: This class represents a field configuration.
QueryConfigHandler: This class can be used to hold any query configuration and no field configuration.

## Package org.apache.lucene.queryparser.flexible.core.config Description

Base classes used to configure the query processing.

## Query Configuration Interfaces

The package `org.apache.lucene.queryparser.flexible.config` contains query configuration handler abstract class that all config handlers should extend.

See `StandardQueryConfigHandler` for a reference implementation.

The `QueryConfigHandler` and `FieldConfig` are used in the processors to access config information in a flexible and independent way. See `TermRangeQueryNodeProcessor` for a reference implementation.