AbstractConfig.java
package dev.orne.config.impl;
/*-
* #%L
* Orne Config
* %%
* Copyright (C) 2019 - 2025 Orne Developments
* %%
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Lesser Public License for more details.
*
* You should have received a copy of the GNU General Lesser Public
* License along with this program. If not, see
* <http://www.gnu.org/licenses/lgpl-3.0.html>.
* #L%
*/
import java.util.Objects;
import java.util.Optional;
import java.util.stream.Stream;
import javax.validation.constraints.NotBlank;
import javax.validation.constraints.NotNull;
import org.apache.commons.lang3.Validate;
import org.apiguardian.api.API;
import dev.orne.config.Config;
import dev.orne.config.ConfigException;
import dev.orne.config.NonIterableConfigException;
import dev.orne.config.ValueDecoder;
import dev.orne.config.ValueDecorator;
import dev.orne.config.WatchableConfig;
/**
* Base abstract implementation of configuration properties provider.
*
* @author <a href="https://github.com/ihernaez">(w) Iker Hernaez</a>
* @version 1.0, 2025-04
* @since 1.0
*/
@API(status = API.Status.INTERNAL, since = "1.0")
public abstract class AbstractConfig
implements Config {
/** Error message for blank property keys. */
protected static final String KEY_BLANK_ERR =
"Property key must be a non blank string";
/** The parent configuration. */
private final Config parent;
/** If parent configuration property values are overridden values of this instance. */
private final boolean overrideParentProperties;
/** The configuration properties values decoder. */
private final @NotNull ValueDecoder decoder;
/** The configuration properties values decorator. */
private final @NotNull ValueDecorator decorator;
/** The configuration properties values variable resolver. */
private final VariableResolver resolver;
/**
* Creates a new instance.
*
* @param options The configuration builder options.
*/
protected AbstractConfig(
final @NotNull ConfigOptions options) {
super();
Objects.requireNonNull(options);
if (options.getCryptoProvider() != null) {
if (options.getDecoder() == null) {
options.setDecoder(options.getCryptoProvider()::decrypt);
} else {
options.setDecoder(
options.getDecoder().compose(options.getCryptoProvider()::decrypt));
}
}
if (options.getDecoder() == null) {
options.setDecoder(ValueDecoder.DEFAULT);
}
if (options.isVariableResolutionEnabled()) {
this.resolver = new VariableResolver(this);
if (options.getDecorator() == null) {
options.setDecorator(resolver::decorate);
} else {
options.setDecorator(options.getDecorator().compose(resolver::decorate));
}
} else {
this.resolver = null;
}
if (options.getDecorator() == null) {
options.setDecorator(ValueDecorator.DEFAULT);
}
this.parent = options.getParent();
this.overrideParentProperties = options.isOverrideParentProperties();
this.decoder = options.getDecoder();
this.decorator = options.getDecorator();
if (getParent() instanceof WatchableConfig && this.resolver != null) {
((WatchableConfig) getParent()).addListener(
(config, keys) -> this.resolver.clearCache());
}
}
/**
* Returns the parent configuration, if any.
*
* @return The parent configuration
*/
@Override
public Config getParent() {
return this.parent;
}
/**
* Returns {@code true} if the properties values from the parent
* configuration (if any) are overridden by the properties values
* from this instance.
*
* @return {@code true} if the properties values from the parent
* configuration are overridden by the properties values from this
* instance.
*/
public boolean isOverrideParentProperties() {
return this.overrideParentProperties;
}
/**
* Returns the read configuration properties values decoder.
*
* @return The configuration properties values decoder.
*/
protected @NotNull ValueDecoder getDecoder() {
return this.decoder;
}
/**
* Returns the read configuration properties values decorator.
*
* @return The configuration properties values decorator.
*/
protected @NotNull ValueDecorator getDecorator() {
return this.decorator;
}
/**
* Returns the configuration properties values variable resolver.
*
* @return The configuration properties values variable resolver.
*/
protected @NotNull Optional<VariableResolver> getResolver() {
return Optional.ofNullable(this.resolver);
}
/**
* {@inheritDoc}
*/
@Override
public boolean isEmpty() {
return isEmptyInt() &&
(this.parent == null || this.parent.isEmpty());
}
/**
* Returns {@code true} if this configuration instance contains no
* property.
* <p>
* Parent configuration
*
* @return Returns {@code true} if the configuration contains no property.
* @throws NonIterableConfigException If the configuration property keys
* cannot be iterated.
* @throws ConfigException If an error occurs accessing the configuration.
*/
protected abstract boolean isEmptyInt();
/**
* {@inheritDoc}
*/
@Override
public boolean contains(
final @NotBlank String key) {
Validate.notBlank(key, KEY_BLANK_ERR);
return containsInt(key) ||
(this.parent != null && this.parent.contains(key));
}
/**
* Returns {@code true} if the property with the key passed as argument
* has been configured in this configuration instance.
*
* @param key The configuration property.
* @return Returns {@code true} if the property has been configured.
*/
protected abstract boolean containsInt(
@NotBlank String key);
/**
* {@inheritDoc}
*/
@Override
public @NotNull Stream<String> getKeys() {
if (this.parent == null) {
return getKeysInt();
} else {
try {
return Stream.concat(getKeysInt(), this.parent.getKeys());
} catch (final NonIterableConfigException e) {
return getKeysInt();
}
}
}
/**
* Returns the configuration property keys contained in this configuration
* instance .
*
* @return The configuration property keys.
* @throws NonIterableConfigException If the configuration property keys
* cannot be iterated.
* @throws ConfigException If an error occurs accessing the configuration.
*/
protected abstract @NotNull Stream<String> getKeysInt();
/**
* {@inheritDoc}
*/
@Override
public String get(
final @NotBlank String key) {
Validate.notBlank(key, KEY_BLANK_ERR);
return this.decorator.decorate(getUndecored(key));
}
/**
* {@inheritDoc}
*/
@Override
public String getUndecored(
final @NotBlank String key) {
final String value;
if (this.overrideParentProperties) {
if (containsInt(key)) {
value = this.decoder.decode(getInt(key));
} else if (this.parent != null) {
value = this.parent.getUndecored(key);
} else {
value = null;
}
} else {
if (this.parent != null && this.parent.contains(key)) {
value = this.parent.getUndecored(key);
} else {
value = this.decoder.decode(getInt(key));
}
}
return value;
}
/**
* Returns the value of the configuration property as {@code String}.
*
* @param key The configuration property.
* @return The configuration parameter value.
* @throws ConfigException If an error occurs retrieving the configuration
* property value.
*/
protected abstract String getInt(
final @NotBlank String key);
}