AbstractParameterizableGenerator.java
package dev.orne.test.rnd.params;
/*-
* #%L
* Orne Test Generators
* %%
* Copyright (C) 2022 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 javax.validation.constraints.NotNull;
import org.apache.commons.lang3.Validate;
import org.apache.commons.lang3.builder.EqualsBuilder;
import org.apache.commons.lang3.builder.HashCodeBuilder;
import org.apache.commons.lang3.reflect.TypeUtils;
import org.apiguardian.api.API;
import org.apiguardian.api.API.Status;
import dev.orne.test.rnd.AbstractGenerator;
/**
* Abstract implementation of {@code ParameterizableGenerator}.
*
* @author <a href="mailto:wamphiry@orne.dev">(w) Iker Hernaez</a>
* @version 1.0, 2022-11
* @param <P> The parameters type
* @since 0.1
*/
@API(status=Status.EXPERIMENTAL, since="0.1")
public abstract class AbstractParameterizableGenerator<
P extends GenerationParameters>
extends AbstractGenerator
implements ParameterizableGenerator {
/** The type of generation parameters. */
private final @NotNull Class<P> parametersType;
/**
* Creates a new instance.
*
* @param paramsType The type of parameters
*/
protected AbstractParameterizableGenerator(
final @NotNull Class<P> paramsType) {
super();
this.parametersType = Validate.notNull(paramsType);
}
/**
* Crates a new instance.
*/
@SuppressWarnings("unchecked")
protected AbstractParameterizableGenerator() {
super();
this.parametersType = (Class<P>) TypeUtils.unrollVariables(
TypeUtils.getTypeArguments(getClass(), AbstractParameterizableGenerator.class),
AbstractParameterizableGenerator.class.getTypeParameters()[0]);
Validate.notNull(
this.parametersType,
"Cannot infer the type of parameters from class %s. Wrong implementation?",
getClass());
}
/**
* Returns the type of generation parameters.
*
* @return The type of generation parameters
*/
public @NotNull Class<P> getParametersType() {
return this.parametersType;
}
/**
* Returns the generation parameters extractor.
*
* @return The generation parameters extractor
*/
public @NotNull ParametersExtractor<P> getExtractor() {
return ParametersExtractors.getExtractor(this.parametersType);
}
/**
* {@inheritDoc}
*/
@Override
public <T> @NotNull T defaultValue(
final @NotNull Class<T> type) {
return defaultValue(type, createEmptyParams());
}
/**
* {@inheritDoc}
*/
@Override
public <T> @NotNull T defaultValue(
final @NotNull Class<T> type,
final @NotNull Object... sources) {
return defaultValue(type, createParams(sources));
}
/**
* Returns the default value for the specified type and parameters.
*
* @param <T> The requested value type.
* @param type The requested value type.
* @param parameters The generation parameters
* @return The default value for the specified type.
* @throws IllegalArgumentException If the specified type is not supported.
*/
public abstract @NotNull <T> T defaultValue(
@NotNull Class<T> type,
@NotNull P parameters);
/**
* {@inheritDoc}
*/
@Override
public <T> T nullableDefaultValue(
final @NotNull Class<T> type) {
return nullableDefaultValue(type, createEmptyParams());
}
/**
* {@inheritDoc}
*/
@Override
public <T> T nullableDefaultValue(
final @NotNull Class<T> type,
final @NotNull Object... sources) {
return nullableDefaultValue(type, createParams(sources));
}
/**
* Returns the default value for the specified type and parameters
* allowing {@code null} values.
* <p>
* This method should return {@code null} except for native types when
* no {@code NotNull} constraint is present.
*
* @param <T> The requested value type.
* @param type The requested value type.
* @param parameters The generation parameters
* @return The nullable default value for the specified type.
* @throws IllegalArgumentException If the specified type is not supported.
*/
public <T> T nullableDefaultValue(
final @NotNull Class<T> type,
final @NotNull P parameters) {
assertSupported(type);
final T value;
final boolean nullsAllowed = !(parameters instanceof NullableParameters)
|| ((NullableParameters) parameters).isNullable();
if (nullsAllowed) {
value = null;
} else {
value = defaultValue(type, parameters);
}
return value;
}
/**
* {@inheritDoc}
*/
@Override
public <T> @NotNull T randomValue(
final @NotNull Class<T> type) {
return randomValue(type, createEmptyParams());
}
/**
* {@inheritDoc}
*/
@Override
public <T> @NotNull T randomValue(
final @NotNull Class<T> type,
final @NotNull Object... sources) {
return randomValue(type, createParams(sources));
}
/**
* Returns a random value of the specified type and parameters.
*
* @param <T> The requested value type.
* @param type The requested value type.
* @param parameters The generation parameters
* @return A random value for the specified type.
* @throws IllegalArgumentException If the specified type is not supported.
*/
public abstract @NotNull <T> T randomValue(
@NotNull Class<T> type,
@NotNull P parameters);
/**
* {@inheritDoc}
*/
@Override
public <T> T nullableRandomValue(
final @NotNull Class<T> type) {
return nullableRandomValue(type, createEmptyParams());
}
/**
* {@inheritDoc}
*/
@Override
public <T> T nullableRandomValue(
final @NotNull Class<T> type,
final @NotNull Object... sources) {
return nullableRandomValue(type, createParams(sources));
}
/**
* Returns a random value of the specified type and parameters.
* <p>
* The returned value has a probability of be {@code null} except for
* native types when no {@code NotNull} constraint is present.
* If not {@code null} behaves as {@code randomValue()}.
*
* @param <T> The requested value type.
* @param type The requested value type.
* @param parameters The generation parameters
* @return A random nullable value for the specified type.
* @throws IllegalArgumentException If the specified type is not supported.
* @see #randomValue(Class, GenerationParameters)
*/
public <T> T nullableRandomValue(
final @NotNull Class<T> type,
final @NotNull P parameters) {
assertSupported(type);
final T value;
final boolean nullsAllowed = !(parameters instanceof NullableParameters)
|| ((NullableParameters) parameters).isNullable();
if (nullsAllowed && randomNull(type)) {
value = null;
} else {
value = randomValue(type, parameters);
}
return value;
}
/**
* Creates a new empty instance of generation parameters.
*
* @return A new empty instance of generation parameters.
*/
public @NotNull P createEmptyParams() {
try {
return getParametersType().getDeclaredConstructor().newInstance();
} catch (final Exception e ) {
throw new IllegalArgumentException("The parameters type has not default constructor. Override createEmptyParams().", e);
}
}
/**
* Creates a new instance of generation parameters with the values
* extracted from the specified sources.
*
* @param sources The sources to extract the parameters values from
* @return A new instance of generation parameters.
*/
public @NotNull P createParams(
final @NotNull Object... sources) {
final P result = createEmptyParams();
getExtractor().extractParameters(result, sources);
return result;
}
/**
* {@inheritDoc}
*/
@Override
public int hashCode() {
return new HashCodeBuilder()
.appendSuper(super.hashCode())
.append(this.parametersType)
.build();
}
/**
* {@inheritDoc}
*/
@Override
public boolean equals(final Object obj) {
if (obj == null) { return false; }
if (obj == this) { return true; }
if (obj.getClass() != getClass()) { return false; }
final AbstractParameterizableGenerator<?> other = (AbstractParameterizableGenerator<?>) obj;
return new EqualsBuilder()
.appendSuper(super.equals(obj))
.append(this.parametersType, other.parametersType)
.build();
}
}