001/*
002 * Units of Measurement Reference Implementation
003 * Copyright (c) 2005-2018, Jean-Marie Dautelle, Werner Keil, Otavio Santana.
004 *
005 * All rights reserved.
006 *
007 * Redistribution and use in source and binary forms, with or without modification,
008 * are permitted provided that the following conditions are met:
009 *
010 * 1. Redistributions of source code must retain the above copyright notice,
011 *    this list of conditions and the following disclaimer.
012 *
013 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions
014 *    and the following disclaimer in the documentation and/or other materials provided with the distribution.
015 *
016 * 3. Neither the name of JSR-385, Indriya nor the names of their contributors may be used to endorse or promote products
017 *    derived from this software without specific prior written permission.
018 *
019 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
020 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
021 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
022 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
023 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
024 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
025 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
026 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
027 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
028 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
029 */
030package tech.units.indriya.unit;
031
032import javax.measure.Dimension;
033import javax.measure.Quantity;
034import javax.measure.Unit;
035import javax.measure.UnitConverter;
036
037import tech.units.indriya.AbstractConverter;
038import tech.units.indriya.AbstractUnit;
039import tech.units.indriya.quantity.QuantityDimension;
040
041import java.util.Map;
042
043/**
044 * <p>
045 * This class represents the building blocks on top of which all others physical units are created. Base units are always unscaled SI units.
046 * </p>
047 * 
048 * <p>
049 * When using the {@link tech.units.indriya.spi.StandardModel standard model}, all seven <b>SI</b> base units are dimensionally independent.
050 * </p>
051 *
052 * @see <a href="http://en.wikipedia.org/wiki/SI_base_unit"> Wikipedia: SI base unit</a>
053 *
054 * @author <a href="mailto:jean-marie@dautelle.com">Jean-Marie Dautelle</a>
055 * @author <a href="mailto:units@catmedia.us">Werner Keil</a>
056 * @version 1.2, August 06, 2017
057 * @since 1.0
058 */
059public final class BaseUnit<Q extends Quantity<Q>> extends AbstractUnit<Q> {
060
061  /**
062     * 
063     */
064  private static final long serialVersionUID = 1721629233768215930L;
065
066  /**
067   * Holds the symbol.
068   */
069  private final String symbol;
070
071  /**
072   * Holds the base unit dimension.
073   */
074  private final Dimension dimension;
075
076  private Q quantityType;
077
078  protected Q getQuantityType() {
079    return quantityType;
080  }
081
082  /**
083   * Creates a base unit having the specified symbol and dimension.
084   *
085   * @param symbol
086   *          the symbol of this base unit.
087   */
088  public BaseUnit(String symbol, Dimension dimension, Q quant) {
089    this.symbol = symbol;
090    this.dimension = dimension;
091    quantityType = quant;
092  }
093
094  /**
095   * Creates a base unit having the specified symbol and dimension.
096   *
097   * @param symbol
098   *          the symbol of this base unit.
099   */
100  public BaseUnit(String symbol, Dimension dimension) {
101    this.symbol = symbol;
102    this.dimension = dimension;
103  }
104
105  /**
106   * Creates a base unit having the specified symbol.
107   *
108   * @param symbol
109   *          the symbol of this base unit.
110   */
111  public BaseUnit(String symbol) {
112    this.symbol = symbol;
113    this.dimension = QuantityDimension.NONE;
114  }
115
116  /**
117   * Creates a base unit having the specified symbol and name.
118   *
119   * @param symbol
120   *          the symbol of this base unit.
121   * @param name
122   *          the name of this base unit.
123   * @throws IllegalArgumentException
124   *           if the specified symbol is associated to a different unit.
125   */
126  public BaseUnit(String symbol, String name) {
127    this(symbol);
128    this.name = name;
129  }
130
131  @Override
132  public String getSymbol() {
133    return symbol;
134  }
135
136  @Override
137  public Unit<Q> toSystemUnit() {
138    return this;
139  }
140
141  @Override
142  public UnitConverter getSystemConverter() throws UnsupportedOperationException {
143    return AbstractConverter.IDENTITY;
144  }
145
146  @Override
147  public Dimension getDimension() {
148    return dimension;
149  }
150
151  @Override
152  public final boolean equals(Object obj) {
153    if (this == obj)
154      return true;
155    if (obj instanceof BaseUnit) {
156      BaseUnit<?> thatUnit = (BaseUnit<?>) obj;
157      return this.symbol.equals(thatUnit.symbol) && this.dimension.equals(thatUnit.dimension);
158    }
159    if (obj instanceof AbstractUnit) {
160      return AbstractUnit.Equalizer.areEqual(this, (AbstractUnit) obj);
161    } else {
162      return false;
163    }
164  }
165
166  @Override
167  public final int hashCode() {
168    return symbol.hashCode();
169  }
170
171  @Override
172  public Map<? extends AbstractUnit<Q>, Integer> getBaseUnits() {
173    // TODO Shall we return null, empty list or what (e.g. Optional in SE
174    // 8)?
175    return null;
176  }
177
178
179}