001/* 002 * Units of Measurement API 003 * Copyright (c) 2014-2023, 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 nor the names of its 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 javax.measure.spi; 031 032import java.util.Set; 033 034import javax.measure.Dimension; 035import javax.measure.Quantity; 036import javax.measure.Unit; 037 038/** 039 * A system of units grouped together for historical or cultural reasons.<br> 040 * Common system of units are "SI" (System International), "Imperial" (British), "US" (US Customary). Nothing prevents a unit from belonging to 041 * several systems of units at the same time (for example an {@code Imperial} system would have many of the units held by the {@code US} Customary 042 * system). 043 * 044 * @author <a href="mailto:jean-marie@dautelle.com">Jean-Marie Dautelle</a> 045 * @author <a href="mailto:werner@uom.technology">Werner Keil</a> 046 * @version 1.1, June 21, 2018 047 * @since 1.0 048 * 049 * @see <a href="http://en.wikipedia.org/wiki/International_System_of_Units"> Wikipedia: International System of Units</a> 050 * @see <a href="http://en.wikipedia.org/wiki/Systems_of_measurement"> Wikipedia: System of measurement</a> 051 */ 052public interface SystemOfUnits { 053 054 /** 055 * @return a name 056 */ 057 String getName(); 058 059 /** 060 * Returns the default unit for the specified quantity or {@code null} if none is defined for the given quantity in this unit system. 061 * 062 * @param <Q> 063 * the compile-time quantity type. 064 * @param quantityType 065 * the quantity type. 066 * @return the unit for the specified quantity. 067 */ 068 <Q extends Quantity<Q>> Unit<Q> getUnit(Class<Q> quantityType); 069 070 /** 071 * Returns a unit with the given {@linkplain String string} representation or {@code null} if none is found in this unit system. 072 * 073 * @param string 074 * the string representation of a unit, not {@code null}. 075 * @return the unit with the given string representation. 076 * @since 2.0 077 */ 078 Unit<?> getUnit(String string); 079 080 /** 081 * Returns a read only view over the units explicitly defined by this system. This include the base and derived units which are assigned a special 082 * name and symbol. This set does not include new units created by arithmetic or other operations. 083 * 084 * @return the defined collection of units. 085 */ 086 Set<? extends Unit<?>> getUnits(); 087 088 /** 089 * Returns the units defined in this system having the specified dimension (convenience method). 090 * 091 * @param dimension 092 * the dimension of the units to be returned. 093 * @return the collection of units of specified dimension. 094 */ 095 Set<? extends Unit<?>> getUnits(Dimension dimension); 096}