001/* 002 * Units of Measurement Reference Implementation 003 * Copyright (c) 2005-2020, Units of Measurement project. 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.format; 031 032import java.io.IOException; 033import java.text.ParsePosition; 034 035import javax.measure.MeasurementException; 036import javax.measure.Unit; 037import javax.measure.format.UnitFormat; 038 039import tech.units.indriya.AbstractUnit; 040 041/** 042 * <p> 043 * This class provides the interface for formatting and parsing {@link Unit units}. 044 * </p> 045 * 046 * <p> 047 * For all metric units, the 20 <b>SI prefixes</b> used to form decimal multiples and sub-multiples of SI units are recognized.<br> 048 * As well as the 8 <b>Binary prefixes</b>.<br> 049 * For example:<code> 050 * AbstractUnit.parse("m°C").equals(MetricPrefix.MILLI(Units.CELSIUS)) 051 * AbstractUnit.parse("kW").equals(MetricPrefix.KILO(Units.WATT))</code> 052 * </p> 053 * 054 * @author <a href="mailto:jean-marie@dautelle.com">Jean-Marie Dautelle</a> 055 * @author <a href="mailto:werner@units.tech">Werner Keil</a> 056 * @version 1.2, $Date: 2019-02-23 $ 057 * @since 1.0 058 * 059 */ 060public abstract class AbstractUnitFormat implements UnitFormat { 061 062 /** 063 * Returns the {@link SymbolMap} for this unit format. 064 * 065 * @return the symbol map used by this format. 066 */ 067 protected abstract SymbolMap getSymbols(); 068 069 /** 070 * Formats the specified unit. 071 * 072 * @param unit 073 * the unit to format. 074 * @param appendable 075 * the appendable destination. 076 * @return The appendable destination passed in as {@code appendable}, with formatted text appended. 077 * @throws IOException 078 * if an error occurs. 079 */ 080 public abstract Appendable format(Unit<?> unit, Appendable appendable) throws IOException; 081 082 /** 083 * Formats an object to produce a string. This is equivalent to <blockquote> {@link #format(Unit, StringBuilder) format}<code>(unit, 084 * new StringBuilder()).toString();</code> </blockquote> 085 * 086 * @param obj 087 * The object to format 088 * @return Formatted string. 089 * @exception IllegalArgumentException 090 * if the Format cannot format the given object 091 */ 092 public final String format(Unit<?> unit) { 093 if (unit instanceof AbstractUnit) { 094 return format((AbstractUnit<?>) unit, new StringBuilder()).toString(); 095 } 096 097 try { 098 return (this.format(unit, new StringBuilder())).toString(); 099 } catch (IOException ex) { 100 throw new MeasurementException(ex); // Should never happen. 101 } 102 } 103 104 @Override 105 public void label(Unit<?> unit, String label) { 106 // do nothing, if subclasses want to use it, override there 107 } 108 109 /** 110 * Parses a portion of the specified <code>CharSequence</code> from the specified position to produce a unit. If there is no unit to parse 111 * {@link AbstractUnit#ONE} is returned. 112 * 113 * @param csq 114 * the <code>CharSequence</code> to parse. 115 * @param cursor 116 * the cursor holding the current parsing index. 117 * @return the unit parsed from the specified character sub-sequence. 118 * @throws IllegalArgumentException 119 * if any problem occurs while parsing the specified character sequence (e.g. illegal syntax). 120 */ 121 public abstract Unit<?> parse(CharSequence csq, ParsePosition cursor) throws IllegalArgumentException; 122 123 /** 124 * Parses a portion of the specified <code>CharSequence</code> from the specified position to produce a unit. If there is no unit to parse 125 * {@link AbstractUnit#ONE} is returned. 126 * 127 * @param csq 128 * the <code>CharSequence</code> to parse. 129 * @param index 130 * the current parsing index. 131 * @return the unit parsed from the specified character sub-sequence. 132 * @throws IllegalArgumentException 133 * if any problem occurs while parsing the specified character sequence (e.g. illegal syntax). 134 */ 135 protected abstract Unit<?> parse(CharSequence csq, int index) throws IllegalArgumentException; 136 137 /** 138 * Convenience method equivalent to {@link #format(AbstractUnit, Appendable)} except it does not raise an IOException. 139 * 140 * @param unit 141 * the unit to format. 142 * @param dest 143 * the appendable destination. 144 * @return the specified <code>StringBuilder</code>. 145 */ 146 private final StringBuilder format(AbstractUnit<?> unit, StringBuilder dest) { 147 try { 148 return (StringBuilder) this.format(unit, (Appendable) dest); 149 } catch (IOException ex) { 150 throw new MeasurementException(ex); // Can never happen. 151 } 152 } 153 154 /** 155 * serialVersionUID 156 */ 157 // private static final long serialVersionUID = -2046025267890654321L; 158}