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microBean™ Bean: Utility classes for implementing beans.
/* -*- mode: Java; c-basic-offset: 2; indent-tabs-mode: nil; coding: utf-8-unix -*-
*
* Copyright © 2023–2024 microBean™.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
* an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
* specific language governing permissions and limitations under the License.
*/
package org.microbean.bean;
import java.lang.constant.Constable;
import java.lang.constant.ConstantDesc;
import java.lang.constant.DynamicConstantDesc;
import java.lang.constant.MethodHandleDesc;
import java.util.Objects;
import java.util.Optional;
import java.util.SequencedSet;
import static java.lang.constant.ConstantDescs.BSM_INVOKE;
import static org.microbean.bean.ConstantDescs.CD_Bean;
import static org.microbean.bean.ConstantDescs.CD_Factory;
import static org.microbean.bean.ConstantDescs.CD_Id;
/**
* A ({@link Constable}) pairing of an {@link Id} with a {@link Factory}.
*
* @param the type of the contextual instances the associated {@link Factory} creates
*
* @param id the {@link Id}; must not be {@code null}
*
* @param factory the {@link Factory}; must not be {@code null}
*
* @author Laird Nelson
*
* @see Factory
*
* @see Id
*/
public final record Bean(Id id, Factory factory) implements Aggregate, Constable, Ranked {
/**
* Creates a new {@link Bean}.
*
* @param id the {@link Id}; must not be {@code null}
*
* @param factory the {@link Factory}; must not be {@code null}
*
* @exception NullPointerException if either argument is {@code null}
*/
public Bean {
Objects.requireNonNull(id, "id");
Objects.requireNonNull(factory, "factory");
}
@Override // Alternate
public final boolean alternate() {
return this.id().alternate();
}
/**
* Returns this {@link Bean}, forcibly cast appropriately.
*
* @param the type of contextual instances this {@link Bean} creates
*
* @return this {@link Bean}
*/
@SuppressWarnings("unchecked")
public final Bean cast() {
return (Bean)this;
}
@Override // Aggregate
public final SequencedSet dependencies() {
return this.factory().dependencies();
}
@Override // Constable
public final Optional>> describeConstable() {
return (this.factory() instanceof Constable c ? c.describeConstable() : Optional.empty())
.flatMap(factoryDesc -> this.id().describeConstable()
.map(idDesc -> DynamicConstantDesc.of(BSM_INVOKE,
MethodHandleDesc.ofConstructor(CD_Bean,
CD_Id,
CD_Factory),
idDesc,
factoryDesc)));
}
@Override // Object
public final boolean equals(final Object other) {
if (other == this) {
return true;
} else if (other != null && other.getClass() == this.getClass()) {
return Objects.equals(this.id(), ((Bean)other).id());
} else {
return false;
}
}
@Override // Object
public int hashCode() {
return this.id().hashCode();
}
@Override // Alternate (Ranked)
public final int rank() {
return this.id().rank();
}
}