org.openstreetmap.atlas.utilities.configuration.Configuration Maven / Gradle / Ivy

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"Library to load OSM data into an Atlas format"
There is a newer version: 7.0.8
package org.openstreetmap.atlas.utilities.configuration;

import java.util.Optional;
import java.util.Set;
import java.util.function.Function;

/**
 * Configuration interface providing key-value look with support for defaults and transformations.
 *
 * @author brian_l_davis
 */
public interface Configuration
{
    /**
     * Returns a set view of all the top level keys in this {@link Configuration}.
     *
     * @return the set of top level keys
     */
    Set configurationDataKeySet();

    /**
     * Returns a returns a copy Configuration specific to a keyword with overwritten values
     *
     * @param keyword
     *            keyword string
     * @return Configuration
     */
    Configuration configurationForKeyword(String keyword);

    /**
     * Returns a {@link Configurable} wrapper around the configured property.
     *
     * @param key
     *            property key
     * @return a {@link Configurable} wrapper
     */
    Configurable get(String key);

    /**
     * Returns a {@link Configurable} wrapper around the configured property.
     *
     * @param key
     *            property key
     * @param transform
     *            applied to the configured property
     * @param 
     *            configured type
     * @param 
     *            transformed type
     * @return a {@link Configurable} wrapper
     */
     Configurable get(String key, Function transform);

    /**
     * Returns a {@link Configurable} wrapper around the configured property.
     *
     * @param key
     *            property key
     * @param defaultValue
     *            value returned if not found in the configuration
     * @param transform
     *            applied to the configured property
     * @param 
     *            configured type
     * @param 
     *            transformed type
     * @return a {@link Configurable} wrapper
     */
     Configurable get(String key, R defaultValue, Function transform);

    /**
     * Returns a {@link Configurable} wrapper around the configured property.
     *
     * @param key
     *            property key
     * @param defaultValue
     *            value returned if not found in the configuration
     * @param 
     *            configured type
     * @return a {@link Configurable} wrapper
     */
     Configurable get(String key, T defaultValue);

    /**
     * Returns a new configuration with contents starting at the provided key.
     * 
     * Assuming the initial configuration is:
     *
     * 
     * {@code
     * {
     *     "a" :
     *     {
     *         "b" : "c"
     *     }
     *
     * }
     * }
     * 
     *
     * With a key provided as "a", the new sub configuration looks like:
     *
     *      * {@code
     * {
     *     "b" : "c"
     * }
     * }
     * 
     *
     * @param key
     *            The provided key
     * @return The sub Configuration if it exists under the key, Optional.empty otherwise.
     */
    Optional subConfiguration(String key);
}