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/**
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* This file is part of the LDP4j Project:
* http://www.ldp4j.org/
*
* Center for Open Middleware
* http://www.centeropenmiddleware.com/
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* Copyright (C) 2014-2016 Center for Open Middleware.
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* 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.
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* Artifact : org.ldp4j.framework:ldp4j-application-api:0.2.2
* Bundle : ldp4j-application-api-0.2.2.jar
* #-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=#
*/
package org.ldp4j.application.vocabulary;
import java.util.Objects;
/**
* A term implementation that enforces the creation of immutable terms defined
* for an {@code AbstractImmutableVocabulary}, which behave as {@code Enum} constants.
*
* @version 1.0
* @since 1.0.0
* @author Miguel Esteban Gutiérrez
* @see AbstractImmutableVocabulary
*/
public class ImmutableTerm implements Term {
private static final long serialVersionUID = 6842492155071877731L;
private static final int HASH_CODE_SALT = 19;
private final int ordinal;
private final String name;
private final AbstractImmutableVocabulary vocabulary;
private final String entityName;
/**
* Create a new term for a vocabulary and entity.
*
* @param vocabulary
* the vocabulary to which the term will belong to.
* @param entityName
* the entity name of the term.
* @throws NullPointerException
* if any of the vocabulary is {@code null}.
* @throws IllegalArgumentException
* if the entity name is not valid.
*/
public ImmutableTerm(AbstractImmutableVocabulary vocabulary, String entityName) {
this.vocabulary = Objects.requireNonNull(vocabulary,"Vocabulary cannot be null");
this.entityName = entityName;
this.name = TermUtils.toTermName(entityName);
this.ordinal = vocabulary.reserveTermName(this.name);
vocabulary.registerTerm(this);
}
/**
* {@inheritDoc}
*/
@Override
public final int ordinal() {
return ordinal;
}
/**
* {@inheritDoc}
*/
@Override
public final String name() {
return name;
}
/**
* {@inheritDoc}
*/
@Override
public final String entityName() {
return entityName;
}
/**
* {@inheritDoc}
*/
@Override
public final String qualifiedEntityName() {
return vocabulary.getNamespace() + entityName;
}
/**
* {@inheritDoc}
*/
@Override
public final Vocabulary getDeclaringVocabulary() {
return vocabulary;
}
/**
* {@inheritDoc}
* This method may be overridden, though it typically isn't necessary or
* desirable. An term type should override this method when a more specific
* value types are supported.
*/
@Override
public V as(Class valueClass) {
try {
return TypeAdapter.adapt(this, valueClass);
} catch (CannotAdaptClassesException e) {
throw new UnsupportedOperationException("Class '"+getClass().getCanonicalName()+" cannot be transformed to '"+valueClass.getCanonicalName()+"'",e);
}
}
/**
* Returns true if the specified object is equal to this term constant.
*
* @param other
* the object to be compared for equality with this object.
* @return true if the specified object is equal to this term constant.
*/
@Override
public final boolean equals(Object other) {
return this == other;
}
/**
* Returns a hash code for this term constant.
*
* @return a hash code for this term constant.
*/
@Override
public final int hashCode() {
return super.hashCode()*HASH_CODE_SALT;
}
/**
* Throws CloneNotSupportedException. This guarantees that terms are never
* cloned, which is necessary to preserve their "singleton" status.
*
* @return (never returns)
*/
@Override
protected final Object clone() throws CloneNotSupportedException { // NOSONAR
throw new CloneNotSupportedException();
}
/**
* Returns the qualified entity name of this term constant.
* This method may be overridden, though it typically isn't necessary or
* desirable. An term type should override this method when a more
* "programmer-friendly" string form exists.
*
* @return the name of this term constant
*/
@Override
public String toString() {
return qualifiedEntityName();
}
/**
* Compares this term with the specified object for order. Returns a
* negative integer, zero, or a positive integer as this object is less
* than, equal to, or greater than the specified object.
*
* Term constants are only comparable to other term constants of the same
* vocabulary. The natural order implemented by this method is the order in
* which the constants are declared.
*/
@Override
public int compareTo(Term other) {
ImmutableTerm self = this;
if(self.getDeclaringVocabulary() != other.getDeclaringVocabulary()) {
throw new ClassCastException();
}
return self.ordinal - other.ordinal();
}
}